2002 Jetta TDI MIL Lamp

Our 2002 Jetta TDI has a recurring Malfunction Indicator Lamp (so called in the owner's manual, the engine-shaped yellow lamp on the speedometer face). Vehicle was purchased in May, under the Certified Pre-Owned program, with 30,000 miles (a lease termination); we've put 10,000 miles on it since.

About a month ago, the MIL lamp came on steady during our commute home. We stopped immediately, read the manual to learn that it was OK to drive unless it began flashing, and drove gingerly home (three quarters of our 40-mile commute remained). The lamp came on steady again, 20 to

30 seconds after restart.

Next morning, the lamp illuminated steady, 20 to 30 seconds after cold startup, so we took it right to the dealership. Performance was unaffected.

The dealership discovered the coolant was low, and -- furthermore -- someone had put the wrong coolant (yellow-green instead of pink) into the cooling system. The service manager claimed '02 TDIs tend to have a recurring problem with low-volume coolant losses, and insisted that his technicians drained and flushed our cooling system, putting in the correct (G12?) coolant.

This past Friday (less than 5,000 miles later), the MIL lamp illuminated steady, just after warm restart, at the end of our commute to work.

I checked the coolant level at it was rather low. Adding coolant up to the "max" line did not help; the MIL lamp came back on 20 - 30 seconds after cold start. Once again, performance seems totally unaffected.

Only service actions since the dealership did the coolant change: an oil change, and replacement of the paper air filter element with a K-N filter element (both by me personally).

The dealership service section cannot squeeze us into their schedule for at least another week, but the technician assured us we may drive the car in the interim with no risk.

Are these people playing games, or being flippant about risk levels?

How often does a steady MIL lamp indication change into a flashing one, and why?

Thanks

cbdr

Reply to
sddso
Loading thread data ...

You got 3 problems.

1- MIL lamp- should be able to fix once a fault scan is done. 2- coolant leakage so there must be a leak somewhere as the engine shouldn't need coolant on a regular basis. 3-"recurring problem" that's the dealer excuse for not being able to find issue #2

Reply to
Lost In Space

What about it being certified pre-owned? Does that have any kind of warranty? Normally when you buy a used car, you get a used car warranty for about

3000 miles or 90 days, ex: (Ford dealer).
Reply to
Peter Parker

I agree and will add only this:

If you are under warranty, then you should be keeping records for possible lemon law issues (check for the possible application of lemon law in your locality)

If you are not under warranty, then don't go to the dealer. They will almost always charge more than an good independent and are generally about equally good. (Note: dealers generally take a more aggressive and expensive approach. This is not good or bad, but it usually means spending more money and getting slightly more reliable results)

My 2002 TDI has had zero coolant leaks and I have not heard of any endemic problems with them That idea sounds like the dealer is ... (fill in your own word.)

Reply to
Joseph Meehan

They're being incompetent. I'd find another dealer.

the MIL is not related to detecting low coolant levels. They got sidetracked with the coolant situation and forgot all about your original problem. They should have scanned the ECU for error codes which would point to the problem. This should be basic stuff for a dealer service department to do.

I'd find another dealer because this one sounds like this might be the start of a big runaround.

Depends on why. The MIL is triggered by any one of a few dozen or so possible error codes/faults related to anything that ultimately effects emissions. So pretty much anything and everything that affects your engine's air-fuel ratio (coolant temperature sensors that tell the ECU how hot or cold the engine is, mass air flow sensor, oxygen sensors, sensors to detect misfires, etc.). The flashing MIL happens when the system detects too much unburned fuel getting into the exhaust system and this will destroy your catalytic converter. Under that condition is when you want to drive the car as little and as gently as possible to a repair shop. Non-flashing MILs shouldn't be ignored, but they are less urgent/serious.

Reply to
Matt B.

Finding another dealer isn't really feasible. We live 35 miles outside Rapid City, SD; the next nearest dealership is likely Cheyenne or Casper, WY (300 miles to either).

The auto is indeed still under warranty, but I don't like the risk of undertaking a 40-mile commute at 0530 each morning, if the steady MIL flicks over to a flashing one.

Another electrical problem seems intractable: the rear window defogger is completely inoperative. Dealer service people replaced the switch, but it persists; they insist all troubleshooting checks come out negative, even after keeping it an extra week at the behest of VWOA HQ. I think they disbelieved my complaint: after all, where does one find frost in July and August? (answer: it can happen any day in the Black Hills, and did on 27 July ... over six inches of snow fell on us last week, later than average for that degree of storm).

Our independent mechanic remarked that the smaller dealerships sometimes blow off thorough fault diagnosis procedures, especially with electrical problems. And he's never lied to me; indeed, he's declined to replace some parts or perform some tasks on other vehicles, when he could easily have done so and reaped extra profit without my knowledge.

Reply to
sddso

In a TDI a blinking MIL usually means a glow-plug problem - not an emergency.

There is a known problem with "coolant migration" through the liquid level sensor and associated wiring (potentially a very bad situation). Sometimes the coolant can work its way by the plug and into the wiring, and through capillary action, can destroy a lot of the wiring harness and connections. The usual fix is to drill a drain hole in the plug housing.

Non-G12 coolant could be a big issue, I think with corrosion problems. I'd make sure it was documented for possible later "discussion".

As others have mentioned, anytime there is an MIL there will be a code stored that they can look up in a manual. Ask them what the diagnostic code was, you can find out what it means somewhere else. If you don't get good answers there is a VW customer phone # you can call for problem resolution. I think they're trying to do a better job lately because they were starting to get a bad rap for poor dealer support just as bad corporate oversight. It might take a little pressure on your part, but keep trying.

I know Mass Air Flow (MAF) sensors are a common problem in these cars, maybe it's something simple like that.

Check with

formatting link
for great info on TDI's.

I have an '02 Jetta TDI and I love it.

Reply to
Wake

As some others have noted, there is not re-occurring problem with low coolant in TDI. If under warrantee, document your visits and get things fixed. If coolant is low, you have a leak that needs to be found and fixed! Also, you do need to use only the VW G-12 coolant.

MIL's do all kinds of funny things - come and go, stay on, etc. It needs to be check and codes read to find the problem, which is probably not related to the low coolant! Again, be insistant with the dealer. Personally, I'd not drive it with the MIL on until you find out what is wrong. It may or may not hurt but why take a chance. If you drive it and it gets worse, VW will blame you and probably not fix it under warrantee!

Unfortunately, VW dealers have a very bad reputation (see TDIclub.com) and VW national customer service is not good either. Every time I took my 02 in for warrantee work, they screwed something else up! Latest, had to have the windows fixed (fell down) which is a known problem and fixed under warrantee. Now, the dome light doesn't work when the driver's door is opened - but they say not related! At the same time, dealer told me I needed new brakes. Took it to my independent TDI mechanic and he said brakes were fine - no need to replace! I've got a dozen more examples. You will have to be very assertive. A good reason to do your own maintenance or find another TDI owner who can help.

JEB

02 TDI Jetta

PS - Rapid City - Used to live in Brookings and traveled to Rapid a lot for work.

Reply to
JEB

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.