thepureride

97, A4 2.8, Manual, Q, Blk/Blk
Check engine light (CEL) went on a month ago. Car has been running great. At that time AUDI diagnosed it with a broken Throttle Postioner Sensor as well as Coolant temp sensor. They fixed them both for about $700. Ripoff, I know, but thats a different story (another time). CEL went back on on my ride home from AUDI after it was fixed. They told me it was a different problem and that it was my T-stat, it needs ti be replaced $800. Ripoff, still not the point.
I took it to a reccommended (non-AUDI dealer)repair place in my area, the VAG-COM threw coolant temp sensor (CTS), they tested both the T-stat and the CTS and they were both OK. However, the guy noticed that I had this residue on the underside of the coolant system cap as well as floating throughout reservoir and possibly the entire system.
Its yellow in color. Sort of a chalky pasty texture and it smells like sulphur.
WHAT IS IT?
COULD THIS BE TRIGGERING THE VAG TO THROW THE CTS CODE?
CAN ANYONE PUT THIS STORY TOGETHER AND FUGURE OUT WHATS GOING ON?
PLEASE HELP.
Thanks
-Jordan

j-bah

brought car to the dealer this week, they told me my coolant was contaminated and was causing the temp light to go off when the car shifted its weight while turning or stoping. they charged me 300 to flush the coolant and replace the tank.

thepureride

..im getting the
CEL.They think its a problem with the T-stat.
I am not sure if the the two are related. But of course AUDI wants to replace my T-stat because its an expensive job with very inexpensive parts (t-stat 15 bucks).
Thanks
-Jordan