hey all, just want to say thanks for the good info thus far
I just picked up a 1997 A6 quattro, 2.8 12v for a song and a dance with a couple warped heads. I fixed the head issues, replaced the wp, t-stat, expansion chamber, cleaned the radiator fins and replaced the fan switch, my main question is whats the normal operating temp on these cars, and is it normal for it to fluctuate a bit.... on the gauge there is 3 lines @ the cold mark and then the next thick line up which I assume is the normal line about half way up... mine will warm up to the half way mark, and stay there during 50 mph or less driving, but anything higher than that its flirts with the third line up from the cold mark.... is this normal, or do I still have some digging to do.... also, @ what point on the gauge do the fans come on, I can ground the pins @ the switch connector, and they come on, but I have yet to hear them come on.
also, is the 1-2 shift under light throttle really @ like 5 mph, or is the trans funny on this thing to.... under WOT it will hang till 5k or better... all other shifts feel firm and fine...

thanks in advance.

joe

 

Joe,

I can't answer your question about the temp gauge, but as to the early 1-2 shift, that appears to be normal. I recently bought a 2001 A6 Avant and it does the same thing.

Mike

 

The temperature gauge is designed to read at the middle over the normal operating range of the engine, so if yours is reading higher, you have an issue. In working on the engine, did you determine the root cause of the head warping issue? Because, it might still be there. You can monitor engine temp (or, at least, what the CTS is sending, which may vary from reality) via VAG-COM. You could wire in some indicator lights, temporarily so they don't have to be real neat, to the fans to light up when the fans get power. This will give you some more data to work with. But, yes, it sounds to me like you have more digging to do.

Good luck,

Bob

 

My temperature gauge sits dead center once the car warms up. I think a couple times in the summer, when the temperature was in the 90s and I was running the car hard, it moved about a needle-width hotter when I came to a stop. The oil temp fluctuates more, between 225-250 depending upon outside temperature and how fast I am running the car (continuous 80-90 mph seems to make the oil run hotter).

 

thats kinda what I though... it doesnt overheat, or run hot really since I did the heads... but clipping down the freeway the temp dropps... granted im in mn, and its been like 4 degrees the last couple weeks, so i have no idea what its like in warmer weather..
I know the root cause was the last owner didnt fix a leaking water pump in time, and when it dumped all the fluid he drove it to a shop to get fixed....
but the I also found that the radiator fins where compleatly pluged up with road grime, the expansion chamber was cracked Im pretty sure the fan switch was out of it..... its kinda been a pain in the *** to get it thus far....
any idea for me to try?

 

I have a 12V and when I purchased the car my gauge was doing the same dance.
I replaced the CTS-sender and for two years now I have no problems.

For number 2), as far as I noticed in summer weather there's no visible correlation between the gauge display at a certain point in time and the moment when the fans kick in. That's just a personal opinion/experience. Others maybe observed some correlation...I haven't, yet.
The auxiliary fans suppose to have their own switch rated anywhere from 85 to 102°C. I may be wrong.

 

Temperature issue is the stuck thermostat.

 

he replaced the T-stat though and the fans switch (just noticed this one)...

 

Good point. But if the conditions of the temp drop is only at high speed and not erratic, then he may still have a bunk thermostat. If the gauge jumps around without being consistent with driving condition, then I agree it is the CTS.

 

it is a odd one... it acts just like a stuck open t-stat, but it did the same thing with the old t-stat... maybe ill replace the temp sensor... im honestly @ a loss guys.... I know my diesel pick up does this exact same thing in the winter, but its a cold blooded pig, and its normal for them to drop temp like this.....