rkvail

Hello,
Was tooling my '97 A8 on Sunday with my parents and three others in the car (5 total). It was 80F and we were puttering around a high-end neighborhood just looking at the homes. Climate control was on at 70F, and after 15 min. of uphill, fairly steep, puttering, the temp. guage was nearly pegged! Just past the last thick mark on the guage, but not all the way to the H. Opened the windows, listened to the jet-engine-like fans going strong, so I know those were working. No idiot lights or sirens, but was very concerend. I turned off the A/C and opened all the windows and started heading down hill. Temp. slowly returned to normal, and seemed OK after 10 min. so I turned on the A/C again only to watch temp. climb well past the normal first fat line. Got home, parked and drove another car for the rest of the day. Last night, I opened the hood to check things out, ran the engine with the A/C on and after temp. climbed to normal, I drove her a bit hard to see if the temp. would go up again, it didn't. Never went past the first thick, line where it has always gone since Nov. when I bought the car. Maybe if we all weighed over 300lbs, I would chalk it up to taxing the cooling system, but nobody was over 190 lbs.(me)

Now, am I being paranoid, or does this not seem right? Coolant level is normal, and never boiled over or anything, I would have seen it in the engine bay. This is the first real problem I have had with the car, and my mechanic is out until next Monday. Needless to say, I have the 8 parked in the garage, and am driving another car until I can figure something out. Any thoughts, or experience?

1997 A8 94k
1993 S4 167k
Ron

KaMaKaZieP -ALUMIN8-

When was the thermostat last replaced?

V8growler

Maybe you have a sticky thermostat? Mine did something very similar lately, driving along happily temp showing 90°C (sorry in the uk so mine is set to °C rather than °F) next minute it's up past half way round the scale. After a couple of these worrying happenings over the next couple of weeks the thermostat just stuck almost closed. I used it with the climate controls set to HI until I could get a new thermostat fitted, could only run for about 20 minutes before stopping to cool it down, never letting it rise too high.
Now the thermostat is replaced it's back to a steady temperature reading of 90°C again and I've had no more problems.
Keep an eye on it rkvail the last thing you want to do is cook the engine.

V8growler

I wish I could type quicker KaMaKaZieP, you just beat me to it. At least we are thinking the same thing. ;o)

PaulW

I would just keep driving it and watch the gage....have you done the timing belt service yet? If not, you're due pretty soon I bet and you'll change it then.

However, it's pretty easy to change the thermostat on a 32 valve motor, it doesn't require anything more than taking the radiator hoses off if I remember correctly.

rkvail

Just checked the records, t-stat was replaced at 74k, so 23k ago. I too thought maybe that was it, but seems real early for a failure?

KaMaKaZieP -ALUMIN8-

Great minds think alike.

airbil

costs a fortune, but still way cheaper than a new radiator. Dont ask how I know =O

PaulW

Actually very easy on the 32 valve motor, very hard on the 40 valve motor

V8growler

That's the problem with failures... we can't always predict them. Watch that gauge like a hawk.