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rec.autos.vw Version:
1 Jan 93 = Inception, more or less.
1 Feb 93 = Removing O2 Snsr; Offrd lights #; tools 1 Mar 93 = Brake rotor edits; VW part numbers; sagging doors; Compression checks; adjusting valves. 1 Apr 93 = Stuff on interchangeability on parts; Rim offsets 1 May 93 = Eliminating rattles & squeaks, updated timing belt procedure, water pump failure diagnosis, added keyword <NOISE> for easy diagnosis, clutch sizes.
1 Jun 93 = CAM Baffles, Index.
1 Jul 93 = Edits.
1 Aug 93 = Chemical Info added.
1 Sep 93 = Edits, Tool info edits, dielectric grease, MTL caution 1 Oct 93 = Edits.
1 Nov 93 = Coolant/phosphates updated, rim ranges. 1 Dec 93 = Corrections on rim ranges, hesitation updates, 1 Jan 94 = Tom Coradeschi reformats. 15Jan 94 = Battery updates, Tire pressures, body care. 1 Feb 94 = Copyright BS added. Charge indicator diagnosis. 15Feb 94 = Split performance issues into its own faq! 1 Mar 94 = Edits, update recall info 1 Apr 94 = Edits. Updated brakes & transmissions a bit 1 May 94 = Remove bushings, edits
15May 94 = More rough idle & black smoke stuff added. 1 Jun 94 = Paint touch up procedure. 15Jun 94 = Updated with ND BBS stuff (coolant, bulbs) 1 Jul 94 = Edits
15Jul 94 = Tesing synchros. Overheating, windshields, seats, rim care 1 Aug 94 = Edits
15Aug 94 = Paintless dent removal.
1 Sep 94 = Inline fuel filter removal. 15Sep 94 = Edits.
1 Oct 94 = Edits
1 Nov 94 = Added some coolant service info, windshield Urethane, maintenance schedule.
1 Dec 94 = Updated FI cleaners.
1 Jan 95 = Updated coolant.
15Jan 95 = Exhaust hangers, retrofittimg programmable wiper control 15Feb 95 = Leather care
15Mar 95 = Approval received for *.answers & archival @ MIT 1 Apr 95 = W6DPO plug comparison
15Apr 95 = Tire build dates
1 May 95 = Vinyl/Rubber Conditioner update Moderator:
Jan Vandenbrande
jan@ug.eds.com
jan@lipari.usc.edu (school address, works) See also the list of contributors at the end. Please feel free to submit any additional info.
Copyright Notice (c) -- 1994:
All Rights Reserved The information contained here is collectively copyrighted by the authors. The right to reproduce this is hereby given, provided it is copied intact, with the copyright notice inclusive. However, the authors explicitly prohibit selling this document, any of its parts, or any document which contains parts of this document. (Inspired from faq.audio ;->)
PURPOSE:
This FAQ is geared predominantly at the technical aspects of watercooled VWs based on the Golf Chassis (A1-A3: Golf I/Rabbit, Golf II & III, Sciroccos, Corrados, Jettas, Vento, Convertibles) using the original Audi "1600 type" engine block (now available up 2 liters) and the new VR6 2.8/2.9l engine aimed at the US/Canadian market. Not covered are the engines/fuel systems available outside North America such as the 1300 cc engines, carburetors/mono-throttle FI systems. These cars have many similarities with Dashers/Passats/Fox's. These are mostly mechanical, but not for the styling, suspension & exhausts. These technical aspects handles issues that will help you maintain the car in near stock conditions. The perfomance FAQ discusses issues to improve upon the stock design.
Quite often, to remain stock complient is as expensive as it is to upgrade to better after market (performance) parts. Shocks and tires are a good example of this. Index:
General issues (tools, VW part no system) Chemicals (Useful chemicals to have around) Engine (Rough idle/stalling, oil filter, more power, water pump, plugs, O2 sensor) Electrical (Bosch # conventions, charging problems, lights, etc) Transmission (CV Joints, shifting, gear oils) Brakes (Types, fluids, rotors) Tires/Rims/Suspension (shocks, tire widths & rim upgrades, performance) Body/Interior (Eliminating rattles, waxing) Miscellanea (Corrado spoilers squeaks)
GENERAL
Q: I have a problem with my car? What do I do? How should I go about fixing it?
- Diagnose the problem as well as you can: When does it happen? Is it speed
dependent? Is there a noise associated with it? Where is it coming from? Is the problem temperature dependent? Happens at start up/after a while? Are there any physical signs such as fluids/grease/wear marks? Does everything look in good order/everything still attached?
While you are going over your car, check whether all the basic things are in order.
VW engines run hot and the 4 cyl. vibrate a lot. As a result things rattle loose and dry out quickly. This in turn causes a host of other problems. Electrical connections & wires: Connectors tend to corrode, wires break internally. Older VWs have a lot of problems which will make you think the car is totally gone while all it may be is a loose wire, or a bad ground. Also check out less obvious things: alternator brushes, fuse box, Hall connections *inside* the distributor? Vacuum hoses: They crack, they leak. Replace where needed. Beware of all rubber components. They wear out with all the heat. If your engine does not run, there are really two main sources: Mechanical and periphery. Generally, VW engines hold up mechanically rather well, and even with mechanical problems you can often get the engine to run. Usually the problem is located with the periphery. You really only need two basic things to make an engine run: Fuel and a spark at +/- the right moment. Suspect a problem with either one first and trace it from there. If for example the problems occurs each time it rains, suspect something wrong with an electrical connection or water leaking onto the fuze box. Yours truly once had problems with a carb and was able to start and run the engine while spraying carb cleaner directly into the intake manifold (with the carb REMOVED). Cleaning the car and engine is often helpful in locating the problem, especially leaks. It also make working on the car so much easier, for you and the mechanic. If you haven't found it yet, read through your manuals and try to identify the offending piece? Ask around. r.a.vw is an excellent source for help, but please be as detailed as you can. If you are having trouble diagnosing the problem, just imagine how hard it is for us not even having seen the car. So *please* don't post: "My car makes a funny noise. What could it be?" Start with make, model, year, and an accurate diagnosis. After you narrow it down to a couple of potential sources, start with the easiest and cheapest fix.
My experience is that a majority of seemingly serious problems can be traced to very simple problems.
Mechanics do NOT have the time to check individual components. Many work on commission (like department stores) and the more cars they work on (not fix) the more they earn. Therefore, they usually take the quickest route for them (replace stuff), and of course you end up paying for that shiny new part through the nose even though it does not fix the problem.
Besides, would you pay a mechanic $200 to fix a 50 cent connector because it took him/her the whole day to find it? Q: I want to work on my VW. What tools should I get? - I'd recommend Muir's (Complete Idiot) Stage I and Stage II tool list. Here
is roughly the "phylosophy" to follow:
Most people start with a couple of tools and then buy more as time progresses and they learn how to work on their car. It makes sense, except that it is usually cheaper to buy the most complete "set" rather than buying a small set and then adding on (e.g., socket "set" - 50 US cents a socket in the largest set, individual = 2-7 US$/piece).
My recommendation therefore is to buy the largest possible set of whatever you can afford. Trust me, you will always be going back for more. In addition, good tools will last you your lifetime!
Next, what brand name should you get. First look for tools with a life time warrantee (though that may not be an indication of quality). In North America, SnapOn, MAC, Stanley, Mechanix, Blackhawk, KD, and Sears Craftsman tools (though their quality and warrantee policy is rumored to be declining).
Avoid cheap tools, they are NOT worth the money, they can do more harm than good (stripping), and may actually hurt you. My order of preference is (and I'll be flamed for this, but this IS based on 15 years of experience): Made in the USA or NW-Europe, & Japan. I usually stay away from Taiwanese tools except for one shot "light" duty items. They are getting better, but so far quality has varied too much to be reliable. A basic set should consist of:
Socket set:
Most versatile is a 3/8" ratchet drive set. It must contain 10, 13, 17, 19mm, and sparkplug socket, a couple extension bars and a 3/8-1/4" adaptor. 12 pt sockets are the most common, but you may want to consider a 6 pt set instead. They are MUCH less likely to strip and break if you need to exert a good amount of torque. Deep sockets are also useful in case you need to clear a bolt. A torque wrench is also very useful. Unfortunately there is no one size for all torques on the car. There are a variety of models: Cheapest are those with a read out gauge. They work well but usually you end up in a position that you cannot read the gauge. I prefer the "click type" torque wrenches where you dial in the desired torque and it will give you a loud click once you attain that. Screw drivers: Get a whole bunch of sizes, spade & Phillips Allen Keys: Get a whole bunch of sizes, though you may want to get Allen key Sockets to use with your 3/8" drive (once you figure out the sizes you need). Wrenches: Get the largest set you can afford. Open and closed. Same sizes as above. Get at least one large adjustable one. Pliers: Again, get the largest set you can afford, regular & miniature, straight, needle nosed. Vise Grips are useful too. Hammers: Get a plastic & rubber one. The "normal" hammers are usually not used on cars except in utter frustration. Jack & Stands: I'd recommend a floor jack over a bottle or scissor jack. A floor jack will make raising your car *so* much easier. Stands are also a must. You don't want you car crashing down on you. Use with wood and some foam rubber to protect you car's undercoating. Lights: At the minimum get a knock-about light with a shatter proof heavy duty lamp in it (don't even *think* of using a regular light bulb, dangerous, and they only last 10 minutes under those conditions). A well lit garage (i.e., 8" neon lamps is ideal). Oil Filter wrench: Different types exist and it depends on what works best for your car. My favorite is the one that looks like an extension bar with a loop of seat belt material.
Air Pump:
Pump up tires...
Tire gauges:
Dial types are usually the most accurate. Odds an ends:
Tie wraps, electrical wires & connectors, elec. tape, vacuum hoses, hose clamps.
"Oh-Oh" Type of Tools:
Occasionally, things WILL go wrong, usually 5 minutes before all shops close on a day before a long weekend, when your other car is gone or your bike has a flat, all your neighbors with tools or out of town, and right before you embark on a long trip, and a very unsympathetic spouse watching on. For many of these, you can wait for a sale, but do get them when you have a chance. Screw Extractor Set/Easy Out:
Get a set, just in case, to remove stripped screws/bolts/brake bleed nipples.
Magnetic Pickup:
Basically a magnet on an antenna. Lose a nut down your intake manifold throat or down a cylinder?...this should help. Don't even *think* on starting the car.
Claw pick up:
Like the above except it has little claws on the end of a flexible tube to pick things up. Similar use as above.
>>>> STILL NEEDS WORK <<<<< Q: My A1 based VW sounds very buzzy and noisy, vibrations in the <NOISE> engine compartment. What's wrong?
- Check the front right engine mount. They wear out in ~50k miles.
From [KIRBY ERLANDSEN]: My tricks are to cut the old one out with a hacksaw (this is easy because you can remove the hacksaw blade and cut from the inside out ) and put the new mount in the freezer while you heat the bracket in the oven. Then with gloves on, you can hammer the two together fairly easily. [Note, oil the components FIRST] If that does not work, bring it to a machine shop and have them press it in for you. See also a1.mounts in the archives. Q: My odometer/trip odometer stopped working. How do I fix it? - This is an old known problem. The odometer gear which drives the 1/10 mile
splits thus no longer engages the shaft to the 1/10 mile digit wheel. You can glue it back with epoxy (after you spend some prime time behind your dash removing the speedometer and opening it up).
Hints on removing: A2's are a lot easier than A1's. The hardest part is unscrewing the speedo cable. Try taking the lower dash covers off and put your hand up from the bottom. Also I just remove the steering wheel before working on the cluster. It makes it a whole lot easier, but be sure your steering wheel and shaft are marked so you can get them back on the same. Otherwise your wheel will be crooked when you drive straight. Reinstalling is harder because you have to be sure the square drive on the speedo matches up with the cluster. Otherwise the cable will not seat fully or the speedo nut is hard to start.
Also, be careful to align the wiring connector before trying to insert - it's polarized. Other hint: I also twisted some fine wire around the flanges of the gear (near the shaft) and put glue over the wire and flanges. Make sure to get the gear back in the proper position under the worm gear. Other hint: I usually go down to the junk yard and look for damaged dashboards and speedo's. Usually one has the gear I need -- I just pry it off -- this is a no cost item if you have a friendly junk yard owner. Other hint: Another approach I used on my '79 Rabbit was to go to a hobby shop and find a small pinion gear for those electric race cars. It had the right number of teeth, and same ID, but was slightly wider and had an Allen set screw.
I filed off the outer edges to clear the other worm gears and mounted it on the shaft with the set screw. Looked weird, but worked OK. The gear will cost about $3 and you need the fine Allen key wrench. You can also send it to have it fixed at: VDO (the OEM) in VA, (703) 665-0100 Q: What is VWs part numbering scheme?
- Each part number is composed of nine numbers in three groups, followed
optionally with a letter suffix (taken from WolfSport's catalog):
vvv ggg ppp [s] vvv: Vehicle type ggg: PRIMARY INDEX 171 = R/G I 100-199 = Engine/Cooling/Clutch 161 = Jetta I 200-299 = Exhaust, Fuel Tank 165 = Jetta II 300-399 = Transmission/Transaxle 261 = 16V GTI 400-499 = Front Axle/Suspension 531 = Scirocco I 500-599 = Rear Axle 535 = Scirocco II 600-699 = Brake 155 = Convertible 700-799 = Cables, Bumpers and Foot control 191 = Golf 800-899 = Body/Interior 900-999 = Electrical, ignition, fuel injection ppp: Individual Part Number s: Suffix, optional
The primary index and the part number are the most important numbers because many of the cars share the same parts. So do not be surprised to see a 171-Rabbit type part in a Jetta. Note that some part numbers are exclusively related to certain parts of the car. For example, vvv = 020 are related to the transmission, vvv = 056 common oil filter. Note: This is scheme has been in use since the Beetle days (111 - Standard Beetle - LHD) but I leave that for the [A] FAQ. AUDI uses the same scheme as well (?). CHEMICALS
NOTE:
This section lists some of the more useful chemicals to use on cars. Be aware that many of these chemicals are harmful if used improperly and could result in stripped paint, rubber becoming brittle, up to poisoning, cancer and death.
Dispose of them environmentally!
See also the section of Waxing for body care chemicals. Q: What are some of the useful chemicals to have around? - Cleaners:
Brake Cleaner:
(Spray) Make sure it's not too harmful for rubber and keep it away from paint.
Carb Cleaner:
Probably a bit dated by now, but the one that was most impressive was Fire Dragon (Spray), however most others work fine as well. If you have an oxy sensor and cat, make sure the stuff you get is compaitible
I also used ChemClean to dunk the entire carb (see below)
FI/Valve Cleaner:
What ever you get make sure it does NOT harm catalytic conv or the oxysensor. The following are recommended and seem to work faily well. They are added to a tank of gas, or fed directly into the FI system. Lubro Molly: there are two products, an injector cleaner and a valve cleaner. You can run the valve cleaner straight through your injection system by hooking it to one of the vaccum hoses and sucking it straight into the valves. Produces lots of smoke but really helped my friends old 924. These are expensive at $12-14 for both. RedLine SL1: works very well and relatively cheap: $3.50 for the 12oz bottle. My current favorite. Chevron Techron: get the real thing, not the ProGuard stuff. Not too expensive at $5.99/20oz bottle. (Imparts, others) Chevron however, warns you not to use it too often between oil changes... (I think no more than 5 treatments) 44K (BG Products): VW also recommends this more concentrated to be used every 4k miles (= VW Part #208 (?)). VW AutoBahn injector cleaner (rumored to be the same as Chevron Techron for a lower price, for once). Chevron ProGuard: only if none of the above is available. I used it a few times, but couldn't tell a difference. I think it contains Techron, but if you can get the real thing... Note that ProGuard is a weaker version of Techron.
General:
"Simple Green": General purpose cleaner (great and safe), engine cleaner It's a non-oil soap (i.e., surfactant) based product that smells like mint toothpaste.
"Chem Clean":
A can or bucket of chemicals that degreases bearings CVJs, or carbs REAL fast (that stuff is amazing). It is however murder on skin and nails. Hand Cleaner: With pumice. Just buy a big vat. They are great, much better than dishwash liquid or regular soap.
Lubricants:
Penetrant oil:
E.g., "Liquid Wrench". Eventually loosens stuck parts. WD40 :
General purpose light "lubricant"/penetrant Anti-Seize:
See below.
Case of engine Oil
Lithium Grease:
Spray can for hard to reach places Molybdenum Grease:
For bearings (NOT CVJs!)
Talcum Powder:
For rubber components
Silicone Spray:
Good for lubricating non-metal components. Rumored to dry out rubber though.
Paint/Body:
Body Paint:
For touch ups/scratches.
Primer:
I prefer cold galvanizing primer
Naval Jelly:
Rust remover (Phosphoric acid, i.e., coka cola). Others:
Brake quiet:
Sticky stuff to put on the pad *backing* to eliminate squeals. Glues:
Depending on what you need to glue, use Epoxy, rubber cement, RTV/Silicone Rubber, etc. ThreadLocker: See below. Distilled water: Battery & for coolant mixing
There is more, but buy some only as you need them because they may dry out. Q: What should I do with Loctite Threadlocker (tm) and Anti Seize (tm)? - Use Anti-seize on anything that you will disassemble again and is subject
to corrosion (water pump bolts, wheel bolts, exhaust bolts), but be careful on sparkplugs and oxygen sensors (it contains lead which kills the cat, make sure it's on the threads only). Use Loctite Threadlocker (medium strength is ok) on anything you don't want to rattle loose and you cannot use serrated o-rings: Brake bolts, etc.
I use anti-seize the most, and if you torque things right, I never had a problem of anything rattling loose.
Note that Loctite also seals out air, and therefore prevents corrosion which means that disassembly will also be facilitated, compared to something rusted shut. A small tube of each goes A LONG way. Q: What power steering fluid should I use? - Be very careful most newer VW cannot use generic power steering fluid.
From the ND BBS:
Just read up in the manual and all VW's use ATF II up till april 89. After april 89 use the special Petrosin hydraulic fluid CHF
ENGINE
Q: I have a very rough idle/stalling/hesitation/bucking problem when the car is cold (or warm in some cases). What can I do to fix it? - This is an old problem that may have numerous causes. Mostly A2
Golfs/GTIs/Jettas/GLIs (8v & 16V) are affected. First make sure everything "obvious" is ok: vacuum (hoses, pipes, intake), electrical connections, tuned up right, spark plugs, distributor, good tank of gas, etc. These are by far the most likely causes of this annoying problem.
[jan, 19930902, overheard in the VW shop] VW is going to embark in some form of campaign, not sure whether it is an actual NHTSA mandated one, to replace all the ECU's with one using gold plated connectors, replace and reroute several vacuum hoses, and replace the throttle body (the shaft has a radial play causing a vacuum leak in some cases). I believe that recent Passats, A2 Jettas and GTIs are included in this. Depending on the model, do the following: - Change to a different brand/type of gas (4-5 tanks) VW had a bulletin out
on this. They recommend Shell, Chevron & AMOCO(?) - Use a good Fuel Injector Cleaner every 4000 miles. See Chemicals
for recommendations.
- Use fuel dryer (using ISOPROPANOL NOT Methanol)
- Check (idle) throttle switch
- Clean sensor plate or airmass sensor & throttle body orifices
- Change the fuel filter
- Clean idle stabilizer VALVE with brake or carb cleaner (VW&P) (Note:
Earlier cars had a Digital Idle Stabilizer circuitry (DIS) which is something different, and *rarely* fails).
For RD (8V) series idle stablilizer problems (& others probably): Symptom: Idles extremely rough when cold, improves after warmup. Doesn't compensate for A/C compressor load when on. Diagnosis: Disconnect the connector from the valve, measure resistance from the center pin to each side, both should be about 12.5 ohms. If either one reads high or open, replace it. (will be about $200 at your Bosch dealer, owww). Reason: The internals of the valve form a bidirectional DC servomotor, the windings of which are connected through a commutator, which has a nasty habit of arcing until the connection is gone.
- Check *all* vacuum hoses (inc. those going to the brake booster & the
brake booster itself)
- Check *all* air pipe connections (esp. between the throttle body & air
cleaner housing). Look around hose clamps, crimped ends, where there may be relative motion and cause a tear. - Check for vacuum leaks anywhere else, e.g., around the intake manifold.
- Check *all* electrical connections (see also later on bad grounds)
Be aware of the old "leak in the windshield molding or firewall gommets that drips and shorts out the fuse box" problem. Many A1's suffer that problem, especially those with badly installed replacement windshield (most places, BTW). - Check inside the distributor (carbon build up will cause misfires/bad idle)
- Check warm-up regulator/thermo switches
- Check proper working of the Oxygen [Lambda] Sensor (see Bentley)
Hint: Disconnect the O2 sensor, if the car runs better suspect that it may be bad.
Replace if suspect. Some O2 sensors will last longer than their expected 30/60k miles lifetime, others fail *much* sooner. Resetting the warning light for maintenance is NOT a good substitute. - Clean contacts of the ECU, and all engine management related components
with an aerosol contact cleaner (note: Newer VWs use gold plated contacts, so this definite a problem area in older cars!) - Check ground of ECU. There is a bulletin out on this. Usually this
failure is acompanied with black smoke billowing from your exhaust. - Check fuel pump relay, it may have an intermittent failure. HARD
to diagnose, until it cuts out entirely. If it does die, jump the two large terminals on the relay block to operate the pump so you won't be stranded. [frank.sikernitsky@mail.trincoll.edu] - Check the working of the injectors (incl 5th one).
- Check the injector O-rings (older cars)
- Clean the tank screen at the bottom of the tank or on the transfer fuel
pump (& also clean the tank if you find junk) From WENDTM@FIRNVX.FIRN.EDU (Mark): When I pulled the hose off the intake side of the fuel pump it only dribbled slowly from the tank! No Gusher! That was a real clue that the tank was faulty, and not the pump. :) - Clean the screen *inside* the fuel pump.
- Check whether the filtering banjo bolt (has a screen) near the fuel
distributor has been removed at the first service (mostly A2 cars with FI in the US, don't know about Europe). It's replaced with a bolt w/o a screen (Part nos: Screw = N 0210715 Washers = N 0138128, for *most* A2 cars). If it is left, it may clog or restrict flow. - Check the health of the fuel pump(s) (measure the amount of current it is
drawing). Note, many A2s have two pumps! - Improperly grounded potentiometer (90 Golf: scottz@pangea.Stanford.EDU)
- Check the CONTROL PRESSURE REGULATOR. Apparently the heating element
wears out, and it won't give correct pressure until it warms up - Faulty oil pump relief valve. Pumps up the hydraulic lifters too much
limiting compression. Apparently mentioned in EuroCar. - If nothing helped, you may need a new ECU! (The 91?,92? Jettas went
through 5 different ECUs, according to my mechanic). - Catalytic converter clogged and breaking up. However, if that happens
it will rattle like a coffee can with coins in it. - If the car bucks/loses power around 3000-4000 rpm when accelerating,
check the full throttle switch. seibed@lamar.ColoState.EDU (Edward Seibert) - >>>> MORE????
- For Vanagons, see VANAGON_Stall in the archives.
Q: What oil filter should I use on my VW?
A: VW's, MANN's or Bosch (OEM). FRAM (PH2870) or other brands do NOT have the same valving (backflow, bypass), valving rates, rigidity of construction, and quality. The other brands will work ok, but you may be running a risk. Several known cases of Corrado G60s blowing FRAM filters open. Some known cases of Porsches ruining engines with FRAM filters due to inadequate gaskets.
MANN filters are also available from Beck Arnley World Parts, and are packaged under that brand, so they are much cheaper than the factory filters. The function of the bypass valve is to bypass the oil filter if the filter is clogged or the oil is too viscous during a cold start. Dirty oil is better than NO oil. The anti-backflow valve prevents the oil from draining out of the engine block into the oil pan. This means that oil will be available almost instantaneously at a start up, which is also when the majority of wear occurs (SLICK 50 is not lying about that). The VR6 engines have this valve build into the engine! [Jan: Compared to the SLC oil filters (~15-20US$), the regular filters now seem cheap (~4-6US$)] NOTE: Newer VWs DO NOT use the same filters as before. The G60 filter is recognizable by the "nut" welded on the bottom, the SLC does NOT use a filter but a replaceable insert (two kinds available, a short and a long one, measure before you buy). Q: I seem to be running hot. What should I do? - Check and do the following.
- Check your coolant level
- Check the concentration of your coolant
- Clean your radiator fins (do that with every wash)
- Check whether the fan still comes on at the correct temps
- Flush the system, check for calcium deposits inside the radiator
and tubes and check the thermostat. Using destilled water in your mixture will prevent any deposits from happening.
- Check whether you have the right pump. Some aftermarket pumps have
smaller impellers and therefore do not pump adequately. - Check whether the bottom radiator hose collapse when the engine
is hot and running. Replacements exist that have internal coil to prevent a collapse. Mostly A1 cars are affected by this. - You may be running too lean
- Your temperature sensor may not be working right. Drop it in
boiling water and see what temp you read. May also be a problem with your system ground.
See also the performance FAQ for other measures. Q: How do I flush my cooling system?
- [From ND]: The proper way to renew the coolant is to remove the thermostat
so as to drain the complete system.
[Jan: This is true for all 4 cyl cars, the VR6's have a drain plug located right next to the dip stick.
Also don't forget to turn your interior heat to max as to drain that too.] [ND] When we do a Coolant service at the shop we replace the thermostat and o-ring with our special low temp 80 Celius unit from Germany. [JAN] I am not sure whether that is advisable in colder climates as the engine may never heat up.
If you still have the stock Fan switch we recommend to replace it with the our low-temp unit which will allow the fan to come on a little early to keep the temps down. If you replace the thermostat we always drill a small air relief hole [1mm] in the main plate of the thermostat so as to prevent a air pocket to develope at the thermostatic bulb and cause the unit to stay closed. Just had a call from a VW owner back east who had this problem. He called to thank me for figuring out why his VW overheated after changing his thermostat. [Jan: I usually don't do it that way, instead I loosen the upper radiator hose and poor the coolant through several channels and then squeeze the tubes to let the bubbles out. However, do carry the rest of the coolant with you on your next drive just in case.]
Another trick to get around the airbubble problem came from Donald Borowski: Heat up the thermostat on a pan of water until it opens, and then insert an asprin pill as it closes. This will keep it open long enough to fill the system and get the air out, and then will disolve. I don't think that acetosalicylic (sp?) acid is very strong, and the amount is rather small. Q: I want to flush my cooling system. Where can I get phosphate free coolant other than at the overpriced dealer prices? - Phosphates corrode aluminum (all VW heads) through an electrochemical
reaction with the cast iron block, which is why VW recommends to use phosphate free coolants.
According to [scornelius@ws11.iac.honeywell.com] Aluminum oxide in solution forms a black paste that makes a real mess, this will be visible inside the coolant bottle once the corrosion process has started (I've seen this in a custom street rod). So if you see a used VW with this condition, run away.... According to [Vincent Yeung] who called Prestone: Phosphate free anti-freeze is necessary in Europe because of the very hard water they have there. Somehow the phosphate in ordinary anti-freeze will react with the minerals in the hard water. However, he said the water in North America is not as hard and he knew a lot of VW with aluminum radiator have no problem using ordinary anti-freeze with tap water. In the US market, all the popular brands until recently (Prestone, Zerex) contain phosphate in a buffered solution which keeps the phosphates in the coolant from ionizing (so they claim), at least for a while. I have used Prestone without seemingly ill effects, but if you want to be 100% sure, not void warrantee, use VW's coolant. Furthermore, mix with DISTILLED water, NOT tap water. Also do not mix coolants of different types. Flush the system before you change! Newer coolants by Prestone (4/60), Arctic, Quaker State and BASF's Zerex Extreme are phosphate free, and are sold with different labels as to clearly identify the new product. They are selling these phosphate free products for environmental reasons! They all advertise around a 4 year-50/60k miles life expectancy. Whether that's purely marketing (the stuff costs more) or a significant difference over the original formulations (that probably will last that long as well) remains unknown.
Unverified claims: Texaco's coolant is also Phos free. Whether these have any long term harmfull side effects (probably not) still remains to be seen (these products were introduce in 93 in the US). Note that VW's coolant is also made by BASF, but seems to be as slightly different formulation than their commercial Zerex product. According to BASF, Zerex Extreme has been approved to be used in VW, BMW, MB, Audi, Saab, and Volvo. Sierra's new anti-freeze is based on Propylene Glycol (environmentally safe). Propylene Glycol is used as a "light" oil substitute in foods and is therefore not as deadly as Ethylene Glycol. See also below for more details. ND has the following to say about Sierra: "Total marketing !! This is just another coolant with a different formula and since most all coolant is recycled now the enviro aspect is mute. This stuff will not work any better than any other coolant. Almost all coolant nowadays is ok to use in your VW. Just make sure it was designed for Aluminum heads which is almost all of them now." Another thing to note is that VW claims that its original coolant does not have to be renewed every two years like Prestone. The reason they give that coolants like Prestone have sacrificing chemicals that prevent corrosion for a certain period. VW claims that their coolant does not have any sacrificing chemicals and therefore does not wear out. Personally, I don't think this is entirely true, and as a precaution, I change the coolant of it turns color or every couple of years. In some of the cars I have owned they coolant looked perfectly fine, in others it turned reddish brown after a couple of months. This is not an endorsement of either products. I have no idea as to their effectiveness. See also the archive file "Anti_Freeze" for additional details, and the performance faq on improving heat transfer. Q: What's the easiest way of removing a water pump (A1 & A2 VWs)? - The idea is to remove the *entire* pump assembly first, and separate the
pump halves outside of the car. To remove the entire pump assembly, you have to remove all "fan" belts, pulleys, the drive belt covers, unbolt the alternator and move it out of the way somewhere, unbolt and reposition the power steering pump (easy once you locate the bolts, there is one on "the other side" that needs to be accessed with a long extension bar, don't need to disconnect the hoses), and unbolt and relocate the AC (don't need to detach any hoses here either).
Then removing the pump is trivial. It's just the rest of the stuff that's a pain, depending on the model. Be patient, there are several hidden bolts/nuts that attach the AC and power steering pump. Tip: Loosen the pulley bolts BEFORE removing the belts. If you are lucky, there will be enough resistance to keep the pulleys steady. If not, I have gone as far as to use a pipe wrench to hold the pulleys steady. Another tip: If your pump leaks between the halves, it's safer to replace the pump as one unit rather than the impeller half. Chances are that the leaking pump is warped, and no matter how often you replace one half, it'll *always* give you problems. Use anti-seize on the bolts during reassembly. While you are at it, check or replace the thermostat. They do get lazy after a while. Checking/replacing the hoses may not be such a bad idea either (note: they last ~ 70k miles or ~10 yrs IMHO). On A1 Diesels (maybe A2) however it's easier to remove the timing belt, and then remove the impeller half of the pump. However [Borowski] the timing belt need not be removed on cars without air conditioning. Once the alternator bracket is removed, the water pump comes out easily. Tip from Greg Welch:
Stay away from non-OEM waterpumps. Some are sold with smaller impellers and as a result do not pump as well (you run hotter). Q: How often should I change my drive belt? - 8 Valve engines, around 60-75k miles, 16V's BEFORE you reach 50k miles. 8V
engines will NOT be damaged if the thing breaks, 16V will be. The VR6 engines use an actual chain rather than a synthetic belt and do not have to be changed.
The only exception to the 8V rule is the Heron head used on European A1 GTIs (not sold in the USA/Canada). It does interfere. Note that tensioning the belt correctly is tricky, if it's too tight you may prematurely wear out a bunch of bearings. If it's on too tight, you'll hear a characteristic whining/high pitched sound. <NOISE>
From [Lee Hetherington]: THE MORAL OF THE STORY IS TO SET THE TENSION BY TRIAL AND ERROR BEFORE YOU PUT THE COVER BACK ON. - I hear an intermittent high pitched chirping noise that comes <NOISE> and
goes when I rev the engine?
- This could be caused by a bunch of things.
First check whether all the belts are on tight enough, but also not too tight (there is a difference between a belt slipping, e.g., when you go through a puddle, and a bearing being over stressed). Remove all belts, and if the noise persists, suspect the drive belt tensioner. (You can actually feel it vibrate when it chirps, but don't get your fingers stuck).
They are easy and cheap to replace, see elsewhere for a replacement tensioning tool.
If that's not it, and the drive belt is not on too tight (see above) then you may be in trouble. - How do I know whether my water pump is going bad?
- Obviously if it starts to leak either through the pump half seam or the bearing (the little hole on the bottom).
However, there are also other failure modes you have to be aware of: If the car makes a grinding whish-whish-whish sound when cold <NOISE> which diminishes as you drive, the pump bearing may be failing and the impeller is machining the pump housing into slivers. To check for this condition, remove all belts, and spin the waterpump pulley. If it turns well damped and smooth, it's fine. If it feels gritty and crunchy, it's machining itself. If on the other hand it spins loosely, the impeller may have detached itself from the shaft. Note that you should not mistake the grinding whish-whish-whish <NOISE> sound from a regular whish-whish-whish noise. <NOISE> In this case the belts may be simply getting hard or the pulleys are out of line.
To check for this, take a can of Silicon spray and spray it on the belts while the car is idling. If the sound disappears immediately, you found the problem.
Either replace the belts, or use some hard soap on them (but don't lose your fingers for this either).
If the pulleys do not line up, check whether any of the bushing are worn (e.g., the rubber alternator bushing as found on older A1 VWs is notorious for wearing out). Otherwise use spacers and O-rings to get them to line up. - Why the hole at the bottom of the impeller housing?
- To keep the bearings dry. Moisture is the death of bearings. Seals are
never quite perfect, thus the hole. From: borowski@spk.hp.com (Don T. Borowski) - Where are the timing marks on A1 & A2 VWs?
- At the top of the clutch/bell housing you will find a plastic plug. Pulling
the plug allows you to use a magnetic factory sensor. If you want to use a strobe, you will have to *unscrew* the whole plug assembly. Then you'll see a reference mark, and an arrow somewhere on the flywheel: Mark in hole: [ ]
^
flywheel: |
Normally the two have to line up under normal idle & a strobe connected to cylinder #1. Some cars require certain vacuum hoses or the idle stabilizer to be disconnected. Check manual. Note: Some cars (e.g. 87 & 88 GTI 16V) also have marks on the front pulley, with an arrow on the end of the block. Note: Excessive advance raises combustion temperatures and pressures, while excessive retard extends the burning cycle through the exhaust and raises exhaust temps. (Mark Shaw) Q: My radiator leaks, what should I do? - Replace it. In most VWs this is pretty easy to do (1 hr), and a new
radiator (which is = OEM) can be had for around 100-150US$. The hard part, esp. in older cars and in Europe, is finding the right radiator. Even VW does not keep track of what car left the factory with what radiator. Furthermore, the serial numbers are not very useful because they may not be available anymore.
What you need to do is first measure the core length of the radiator, then determine whether it has an external recovery tank, and then determine whether it is screw in mount (mostly pre-82) or the newer pin-points (Wolfsport has some good explanation of this). Now you need to decide whether you want the same radiator, or a larger one. Most VWs come pre-drilled to accept certain larger radiators. Larger radiators are used in cars with A/C, or if the car is destined for a warmer climate (though that may not be where the car is sold). You also may want to install the largest possible radiator if you autocross, do long desert runs or tow something. A larger radiator allows a larger cooling capacity, which means it can dissipate heat quicker. This does NOT mean that it will run cooler on *average* because that's controlled by the thermostat (a.k.a. "aquastat" in some places).
Some 3rd party places (e.g., JC Whitney) sell generic radiators with a conversion kit which are much harder to install, and not recommended.
Whatever you do, avoid the temptation to use one of those Stop Leak products at all cost because it'll block more than just your leak (like the heater core). rgolen@UMASSD.EDU Q: What causes engine knock/pinging/detonation? <NOISE> - Too much advance. Check Timing. Also check VALVE timing. Too low gas
octane/too high engine compression. Engine overheating. Carbon build up on valves. An improperly torqued knock sensor can cause the sensor to not function correctly resulting in knock and/or loss of power. Failing knock sensor.
NOTE: Do not mistake engine knock or pinging for other problems. Knock occurs under load (e.g., accelerating, going up a hill, fast driving). Knock seldom occurs under no load conditions (e.g., idle or revving the engine). If you hear a rattle there <NOISE> it may be something else: valves, bearing, wristpin slap, etc. Q: I have an A2 VW and I hear buzzing from the rear of the car? <NOISE> - These cars have two fuel pumps: The transfer pump which is mounted *inside*
the gas tank, and the regular pump which pumps the gas to the fuel distributor.
Just before you start the car (key in "on" position) you should hear a slight buzzing that MUST go away after 5 seconds. Whenever the buzzing noise becomes increasingly more audible while driving, it may indicate that one of the pumps is about to fail. Changing the fuel filter may help. Bentley manual has a procedure to check the health of the pump, basically by measuring the current being drawn. Cleaning the fuel filter screen with the transfer pump also seems to help.
The transfer pump makes a 'wugga wugga wugga' noise when the key is turned on, and then goes away. Q: I seem to have lost power?
- Check the following:
- Vacuum hoses
A: Check the manual, however the manual/Bentley/dealer may sometimes be wrong. Here is some info collected over time: Some regular Champions do not work well with VWs. Bosch are the stock plugs, and work well in most VWs. NGK seems to be a suitable replacement for some cars. 8 Valve up to 87: WR7D? where ? = S, P 9A Engines (16V from August 1989 - present): Bosch FR6DS - ZVP121086S Bosch F6DTC - equivalent (see differences below).
Corrado G60: Bosch W6DPO - VW# 251 201 511A (at 16US$ EACH!). Corrado VR6: Bosch F7LC0R2 - Weird beast! NGK ZFR6F-11 (VW now sells these as a replacement) Champion C9MCC (OEM, manual incorrectly lists these as Bosch plug, seem to work better than the Bosch's)
Golf & Jetta III,
Cabrio
with ABA engine Bosch FR8DS - 101 000 044 AA, see TSB V28-94-01 Jetta GLX, Passat GLX,
SLC with AAA engine NGK BK5REKU - 101 000 035 AB, see TSB V28-94-01 (see also the Performance faq on additional sparkplug info). Q: What does the Bosch spark plug number mean? - For example: WR7DTC
W = Diameter (?) W= 14 mm (?)
R = Resistor (Radio interference suppression, not vital(?)) 7 = Heat Range (lower numbers = colder plugs) D = Length (?)
T = Tri-cathode. If missing, single cathode C = Copper Anode.
Other values, Missing = Carbon, S = Silver, P = Platinum Q: Why is the G60 plug 15US$? What's so special about it? - The WR6DPO plug is closer to a performance plug because it gap is not
covered with the little prong but rather exposed to the combustion chamber. Supposedly it gives you a better combustion and the engine runs cleaner.
Conventional: === <==Gap
// []
W6DPO Gap
\/ Q: Should I use Platinum plugs? [Note, Bosch & NGK & Others make them]. - Only if it is recommended by either the sparkplug or car manufacturer. The
results have so far been mixed. Some people feel a marked and sustained improvement over regular copper or silver plugs others felt a decrease in performance and cold starting. - How do I adjust the gap on Platinum sparkplugs?
- Depending on the type of Platinum sparkplugs, to make the gap smaller, you
gently tap the cathode on a solid piece. - I need to replace my muffler. What should I get?
- See the performance FAQ and also the archives on this!
<ADD A SECTION ON HOW TO FIX EM> - How do I remove the oxygen sensor? It seems frozen.
- [From: rkast2+@pitt.edu]
First you need the right 22mm wrench. And now the story from Rajiv: Then he explained to me the secret of how he got it off.
[Applicable to the 1 wire systems attached to the exhaust manifolds ONLY, the heat would ruin the catalytic converter, for those mounted on the converter]
The sensor area needs to be heated, either by running and/or torch. Then, you spray lots of penetrating oil into the slight crack, where it gets sucked in by the pressure drop and by the cooling. This gets the lubricant to the threads. (I remember hearing that drilling holes just to the threads is a good idea). Keep doing this repeatedly and keep applying the wrench. Sooner or later (took them 1 hr) it'll come off. Q: What does an engine compression test tell me about the health of my engine? - There are different ways to check engine compressions, and they can reveal
specific internal defects.
General procedure:
- Remove all spark plugs.
- Ground center spark plug wire AWAY from the cylinders
- Make sure you have a healthy battery & the car is at operating temp.
- Attach compression gauge on cylinder 1
- Put car in neutral & have friend push in clutch & accelerator
- Have friend crank engine, note FIRST reading and reading after
pressure stabilizes (3-5 cranks). - Note down readings and repeat for all cylinders
- A healthy engine should have all readings near mfr's spec, and should
be about +/- 10% of each other. If not...you are in trouble. - If one or more is low, but not adjacent cylinders (e.g. 1 & 3)
suspect either a burned valve or worn rings. If adjacent cylinders are low, also suspect a bad head gasket or a warped head. - To determine whether it's rings or valve, do a leak down test => Add
a couple spoon fulls of regular engine oil to the engine through the spark plug hole of the offending cylinder - Repeat measurement. If it remains low => Valve/Head, else if the
readings jumped up => Rings.
- To distinguish between head vs valves => see a professional. They'll
lock the drive shaft, put air pressure on the cylinders and watch for bubbles in the coolant fluid.
- Also the first reading and the final readings should not be too far
apart.
- How often should I adjust my valves (gas engines)?
- All/most? VWs made after 1985 have hydraulic valves, which adjust
themselves. Cars before that need periodic adjustments. Check for the recommended intervals in your manual, do more frequently on older cars & with periodic compression checks. Badly adjusted valves reduce power, increase pollution and may lead to burned valves (valves cool thru contact with the head).
It's a fairly easy job to do, you DO need two special tools: One to compress the valves and one to remove the adjusting shims. They can be had at most car specialty stores.
All VW engines based on the old 1500 thru 1800 block use calibrated metal shims (tappets) the size of Alka Seltzer pills for adjusting the valves. You first measure your clearance, then determine how much off it is, take out the old shim, calculate what new size you need, and race of to your parts supplier (or use a shim from another valve). - What's a CAM "saver" cover, alias CAM splash guard, alias CAM cover baffle?
- It's piece of plastic that fits between the actual CAM cover and the upper
CAM bearings (just wedged between the two). When the car is running, oil is splashed around a lot in the CAM chamber (just try it...you'll have to repaint your garage) and sometimes saturates the positive crankcase ventilation valve.
The PCV is connected to the breather tube on top of the CAM cover and goes to the airfilter box. When the PCV gets saturated it my drip oil into your airfilter box. The CAM saver cover prevents oil from splashing directly on to the inner CAM cover, and also allows oil to drip back directly on the CAM providing extra lubrication instead of just sliding back along the sides. Both VW and certain after market places sell these barriers for about US$ 15.
Many of the newer VWs (87 GTIs) have such a barrier installed as stock, but you can often retrofit your car with it as well. Note that these things not always fit quite right... According to Graig: You need to buy a new cam cover gasket set too as you'll be junking your old one when you take the cam cover off. If you have an aftermarket cam cover, trade it in for a factory one, as the actual oil breather itself has a better baffle (rather than just a screen or mesh like in some aftermarket ones). This is a safe preventive too, even if you don't autocross. Everyone who even thinks of driving their VW hard should put one of these baffles in there - How do I remove bushings from a blind hole?
(For example: small bushing on the right side of the clutch throwout shaft) - There are several methods:
- tap it (with a thread tap), screw a bolt into it, and draw it out.
- this is real slick, and it often works (I use it for pilot bearings
fill the blind hole with grease, find a bar that fits nicely in the bushing (often a junk part like the one that came out of it), slug the bar with a hammer and the hydrolic press will force out the bushing (really does work!!!)
- You just get the appropriate bolt that will JUST thread into
the soft bushing material. As you thread it in to the bottom it will pull the bushing out (when it hits bottom). - Cut/grind a washer so that it's just
barely bigger than the bushing on two sides, and smaller than the bushing on the other two sides. Put a screw through the hole on the washer. Work this washer into the blind hole until it gets BEHIND the bushing (assuming the bushing doesn't go all the way back). Then straighten the washer out so that the two long sides are against the back of the bushing, and tug heartily on the screw with either a slide hammer or a prybar, depending on which presents the best potential for leverage (in my case, a slidehammer wouldn't fit into the confines, but a pair of long-nosed Vise-grips worked perfectly -- the long nose worked as a pivot point against a perfectly-positioned bulge in the differential housing, sort of like a wheelbarrow, and a good tug got the bushing out).
- How do I check (and remove) for the inline FI filter
in early A2 cars, and how do I remove it if there. - This filter is installed by VW apparently to filter out
contaminants remaining from manufacture that are in the fuel system *after* the main fuel filter, but will continue to catch junk the main filter misses. Pre-Digifant/Motronic A2's are affected (CIS, CIS-E). Failure to remove this bolt may clog the system.
This filter is located inside the 'banjo bolt' that connects the fuel line to the fuel distributor. This bolt is hollow, and the filter, about the size of a long pencil eraser, is hiding inside.
Here is the procedure I used to check for and remove the filter I found in the GTI: - Buy two copper washers to replace the ones on the banjo bolt,
or you will suffer a fuel leak like I did. - HAVE A FIRE EXTINGUISER WITHIN ARM'S REACH!! - Start engine, and pull the fuel pump fuse while it is running
to depressurize the fuel system, or a faceful of gas awaits. - Remove the banjo bolt associated with the incoming fuel line
(don't confuse it with the return line) with a 17 MM wrench. A small amount of fuel will dribble out, nothing a paper towel or two can't handle.
- If your bolt is hollow, celebrate and put everything back together.
Torque bolt per Bentley's spec for your car. - If you see something inside, try to poke it out through the side
holes in the bolt. That failing, whip out your drill with a 1/4 bit, and *gently* apply torque with the bolt supported in a vise. In my case, the bit grabbed the filter, and I was able to withdraw it. Admire the filth, then clean the bolt well before reinstalling it with the new washers.
Alternatively, you can also buy the new screw Part nos: Screw = N 0210715 Washers = N 0138128. - Don't forget to put your fuel pump fuse back, or the car won't start!
Q: My exhaust bangs against the rear axle/my muffler hangers brake frequently.
A: This is a common problem on certain cars (e.g., A1 Sciroccos and early G60 Corrados).
Check the following:
- Realign the exhaust pipes
- Check front engine mount(s)
- Replace the hangers with stronger units.
The most common hangers used in A1/A2 cars up to ~1991 look like rubber donuts with some rubber in the middle. I bit like an "0". There are two stronger versions of the "0" hanger available: 840 253 147 A: It looks a tad different but probably work; 171 253 147 G: This looks identical to the original "0" but has has a chain molded internally and hence cannot be twisted sideways nor break.
Some cars also use rubber donuts without a center piece: 191 253 147 A and they look like an "O" with a tab on one end. The newer A2 & VR6 cars use a different hanger system, and those hangers look more like a piece of stretched caneloni.
ELECTRICAL
Q: On the electrical diagrams, do the circuit numbers have any meaning? - Yes. VW uses Bosch numbering scheme, as do BMW & M-B. The most common ones
are:
1 = Ground (0 Volt)
15= Switched Positive (Hot when ignition is on) 30= Always hot "12 Volt" (even though it'll closer to 13.4 Volt) - My battery is not charging well, I am only showing 12V when charging rather
than 13.4V. What is wrong?
- There are numerous causes for this. Most of the time the problem is fairly
trivial. Going from cheapest to most expensive, try the following: See also charge light diagnosis below. - Check the ground connections, possibly install a new ground from
alternator to battery rather than using the engine block/transmission as conductor. Forget trying to find the bad connection with an Ohm meter: Say your alt. puts out 50 Amps, you'll get a drop of 1 Volt for each .02 Ohm!!! Most VOMeters are not accurate enough in this range. So, those tiny little resistances that have build up over the years REALLY add up.
Use a THICK (10 or less Gauge/"AWG"), multistrand wire. - Check the alternator wiring harness. Same reason as above.
- Clean all related connectors (sand paper, file).
- SOLDER ALL crimped connectors
- Check for an unusual drain (unlikely but possible)
- Check/clean/replace the alternator brushes (easy, see wear limits in
Bentley).
- Check the battery water level (use distilled water)
NOTE: DO NOT ASSUME YOU HAVE A MAINTENANCE FREE BATTERY BECAUSE IT DOES NOT HAVE LITTLE SCREW TOPS. MOST VW BATTERIES ARE NOT MAINTENANCE FREE AND THE WATER LEVEL SHOULD BE CHECKED PERIODICALLY! - Have the battery checked (it may be shorting out)
- Have the alternator checked (diodes and regulator may be bad). Alternator
replacement is by the way trivial. If the alternator is bad, upgrade to a higher amp one, especially in older cars and if you have a powerful stereo system or aux lights 90 amp replacements are the current "hot" ticket. Euro car had a detailed procedure on this about 1 or 2 years ago.
NOTE: Many car parts places will check out your alternator for free or a very low cost. Sears used to do it for free in the US if you had a DieHard battery, now they charge some nominal amount. - Replace battery connectors with better quality ones. (From D.J. Stern: number 1 or number 2 gauge Whitaker brass-terminal battery cables.)
Q: My charge light does not behave as expected. What is wrong? - Taken from EC (March 1994):
The charges light is directly connected to the excitor part of the alternator. It provides the initial power to get the alt working. And it also provides alot of additional info:
Engine off, ignition on, no charge indicator: |
