Hey all,

This is my first post on the forum. I have owned a 1996 2.8L A4 quattro since last march. (Wile the check engine light was on) I recently failed an emissions test (needed for my tabs) and went to get the car looked at. The reason I failed was becasue it said my engine coolant temperature failed. I went to a place that I have had work done in the past and was told that I needed a new thermostat because my engine was not getting up to running temp. He quoted me $800.00. I took the car without getting the work done (not totally trusting of this shop). Since that time (a week) I have been able to get the car to operating temp. and the check engine light has not come back on. So I took it to the emissions place again and when they went to test my car, they said that the computer had not been reset yet, and they could not even test my car. They said that when I had work done, the mechanic probably cleared the codes and that the computer had not gone through a drive cycle and the computer had not been reset.

Since then I have called and talked to another mechanic (friend) who said that he thought I had the right idea and that as long as the engine was warmed up and the check engine light was not on that I should pass the test, but that I would have to wait until I had driven through a drive cycle. Long story short...WHAT IS THE DRIVE CYCLE FOR AN A4, how long do I have to dirve before my computer will reset and the emissions place will be able to test my car?

 

never heard of a "drive cycle" that resets your CEL....it sounds like you may have a failing temp sensor (STF for another thread i just posted on a fwe minutes ago). i had a similar problem a couple months back...but it could possibly be your thermostat also...although 800 is a RIDICULOUS price for a thermostat...

 

$800.00 was with labor obviously, but I don't trust the guy very much. He actually replaced my temp sensor this summer, after about two or three months the warning light came back on. This time he says it is the thermostat. My mechanic friend said that it sounded like the valve on my thermostat may be stuck open because, it takes good half hour to warm my car up to running temp. But he said that, that probably would pass my emissions if i could drive until all of the codes reset!

I also had never heard of a drive time, that is why I posted this. The emissions people and the mechanic (friend) told me that after codes have been cleared by the mechanic, it takes the car a DRIVE CYCLE to reset. ????????

Maybe someone else will know. Thanks for your help.

 

If no other problems exist or the problem has been fixed the CEL will reset itself after 100 miles or so. You can also speed up the process by disconnecting your battery for a half hour or so. You'll need your radio safe code too, which should be in your owners manual.

 

if your temp sensor was recently replaced, and it takes that long for your car to warm up, than it probably is your thermostat...i just had my timing belt replaced a few months back, it cost $800 for everything (timing belt, serp belt, tensioners, rollers, water pump, and thermostat) and that also included labor...

 

Thermostat replacement sounds in order. It sounds like yours is stuck open.

Why don't you find someone local with a VAG-com to clear your code and then have your car checked for emissions.

 

linky

 

Thanks all. You have helped and confirmed a lot of my suspisions. I think that the thermostat does need to be replaced, but I am pretty sure that I can pass emissions after the codes reset through the drive cycle (I HAD THEM CLEARED).

It is my understanding that the water pump and the timing belt are all located inthe same area as the thermostat so it is probably a good idea to have all those done at the same time. I do not know when the owner before me replaced the timing belt. I have owned the car for a year. What is the normal lifespan of a timing belt (and for that matter water pump, etc.)?
I will probaly get those done at the same time and I will estimate that I should look for a quote of around $800.

Thanks again.

 

timing belts should be replaced after 60k miles. audi suggests every 90k, but if you ask most of the people on this forum, after about 75k youre driving at your own risk...buy a snub mount and have that replaced at the same time...i didn't do this and it's going to cost me a few hours of my time to install it myself now...if you browse the forums from today you'll find a couple other threads about timing belt replacements that will tell you all you need to know...

 

Not sure on the 2.8 but on the 1.8t the thermostat housing is easily accessible from under the car, maybe it's located in the same general area. The housing (if it is standard on all a4's) is held on with 2 10mm bolts, then when you pull the therm. it will spray coolant on every thing around you, even if you have drained it from the system. If it is in te same area, it's not a bad replacement job. But when mine failed emissions, the mechanic reset the ecu, hade me drive it for like 2 days and rescanned it and it all passed. Just fyi I guess.