El Shaggy

I've had my '01 2.8 30v for over six months now. Its been a great vehicle I think I chose the best engine model available for my price in an A4. So my check engine light came on one COLD morning and even before that i noticed my Engine Temp Gauge has been sluggish to lift from the low end of the dial.

So my brother(into VW GTIs) told me I would need some one with Vag-Com to check the code and reset it. I called around asking motorsport/tuning shops if they had one, long story short I paid some ******* $40 to use an OBD-II that I could have gotten checked for free. But I learned some about my airbag light and ABS light(front Driver sensor is out).

I did some digging around here and its apparent I should swap out the Coolant Temp Sensor. I didn't see much info on replace a thermostat while I was digging around. Would the thermostat be causing my Gauge to basically be in non working order?

I work at the Auto Value Distro center and plan on getting it from their shop. I know most people would suggest I go to the dealer, but they have this whole "Import cars aren't foreign to us!" Promotion so I want to make sure they can deliver and if they can't I am going to make a fuss to the CEO. (Corporate is attached to the warehouse so I see him often) Thanks in advance for any advice!

AudiMick

The coolant temperature sensor is easy to change. The sensor can make the gauge read in-correctly. That sensor type is actually (2) sensors in one and is used in several other manufacturers vehicles. They are cheap, get the O-ring and plastic clip also.

If you can borrow a VAG.com you can check the coolant temperature. It should be 89C when warmed up and should not fluctuate much.

If your car is taking a while to warm up on cold mornings, or actually cooling down slightly on the highway it is more likely to be the thermostat.

Part is also cheap. I would buy from the Audi dealer for this one. Audi thermostats fail open (what you are experiencing) whereas aftermarket tend to fail closed . If this ever happens again the former is preferable.

Replacing the thermostat on a V6 is 90% of a timing belt job or about 4 hours work.
The reason replacing it is so hard is that the thermostat housing is behind the timing belt, so the timing belt has to be loosened to allow enough slack in the belt to remove the housing and thermostat. There is real possibility of the belt jumping and messing up valve timing if you are not careful. It can be done but is not easy. I have done it a couple of times.

IMHO this is probably a thermostat problem, this is the classic symptoms of failure and every year about this time the forums have several of these kind of posts. My heater doesn't blow warm etc.

El Shaggy

Thanks for the great response. I'll try the sensor this week and probably dig into replacing the thremostat next weekend if thats what my issue is. I've had some experience tearing down past a timing belt with previous vehicles (Talon TSi). I am pretty comfortable getting my hands dirty. Now the real question is do I spring for the Bentley manual or just grab a Haynes?