I have a 1996 audi a4 quattro and recently my temp guage has been dropping when i drive and my heat is almost not working(i feel a little heat after a while). than when i come to a stop the temp guage starts rising again. The other day I noticed the coolant was almost gone so i refilled it but the im still having the same problems. Whats going on? please help

 

Your thermostat has failed and is stuck open. When you drive the slipstream air cools the coolant too much to heat the climate air, but when you're stationary, the coolant keeps enough heat to warm the cabin. You have to tear down the front of the engine to fix it so do your timing belt service while you're in there (to avoid duplicating the labor later on). If you're decently adept with a wrench it's a straightforward DIY. If not, where are you located? Several of us work on Audis on the side and can probably save you a fortune in labor costs.

 

This happened to me too.

****.

 

Thanks for answering, i live in chicago Il when i was driving today i cranked up the heat all the way and it started working although not as well as before. Am i damging my car by driving it in this condition?

 

While it's certainly not ideal to run your engine below the 'warm' temperature, it's not going to kill anything. I'd suggest doing the thermostat as soon as you can and then doing an oil change immediately after. Running the engine at the cooler temperature will increase the likelihood that some fuel/air charge could make it past your piston rings and end up in the crankcase oil.

 

Agreed. Until it's changed you'll also probably lose some gas mileage since with the car will not be up to temperature and the ECU may (depending on how warm the engine gets) continue to run on its cold-start fueling maps, which are richer than normal running maps.

 

Thank guys. It was the ******* thermostat....pain to repair but at least i got all the belts switched out so my car is freshened up

 

hey devil i have a similar problem, im almost certain its my thermostat however, i get heat, good heat. but my temp gauges sit very low. sometime the main temp gauge hits about 40% but my question is, do you think that will cause problems, being the ECU reading the temperature wrong?

 

Yes, probably. If you truly get good heat then it sounds like the coolant temperature sensor, and yes, that can make your car run poorly. Check your coolant level and the connector on the coolant temperature sensor to start. You may also have a partially bad thermostat. It should normally cause no heat or overheating but it may have failed in an odd way.

 

hmm ok,
so when i first got my car in October it had low coolant, still above the "fill" line but lower then id prefer.

the heat is good, it feel slightly "sluggish" to get hot but not in an unreasonable manner.
im averaging about 250+miles per full tank(id say it usually hits about 230 before i fill up) but im also filling up at 1/4th tank every time. only once have i gone anywhere close to 1/8th tank.

the take off for a 1.8 doesn't feel sluggish by any means, quick for a 4cylinder in my opinion, nor does it idle rough, sound funny(point is, no noticeable concerns).
[fyi its a 2000 1.8TQ manual, ATW]to my knowledge its completely stock.
i had my oil changed and haven't looked at the coolant in about 500miles or so, ill check it tomorrow.

So it just leaves me with low gauges.
should i be concerned about it at all? or just wait till i do my timing belt?(prolly this summer)