sapman

Noticed Saturday afternoon temp gauge was not reaching the normal mid-point (90c, I believe, my car came from Canada). Today wife drove 40 minutes to work, and still never heated up fully, as well as heater not blowing very warm. I think the heater core is somewhat plugged anyway, but the engine temp was always consistent.

Mechanics say they've never or rarely seen failed thermostats on A8. But I can't imagine what else it is. Anyone ever have one go?

Thanks,
Tim

bmwm750

It doesn't seem to be a common item on these motors, but from what you describe, that's pretty classic bad German car thermostat.

On a side note, and no surprise here, German cars have thermostats that fail open, so the car never warms up if it's cold and a German guy says "wow, my car is running like crap, I better get this fixed." American cars fail closed, since the engineers know that the average American would never fix it if it didn't overheat!!

Brozee

The thermostat is a common item to fail on the A8. "common" is relative though, but I have experienced/ seen it fail on many different A8's.

Mister Bally

Mine failed "closed" in my A8, in the summer. Had to replace it and did the timing belt etc. All of my other VW & Audis failed in the open position; in the winter.

Only exception was the one in my originalBeetle. Never failed. Alas that one adjusted flaps as the engine was air-cooled. My '01 New Beetle Turbo still has the original thermostat.

I spoke too soon. My '01 Beetle turbo's thermostat failed in the open position. Poor heat when driving on the highway and a long warm up (thank goodness it has heated seats) It was a PITA to replace today but not nearly as bad as on a non-FSI Audi 4.2L engine. Ballykid got to learn another repair.

sapman

That American response may be ours as well for awhile, as the budget is kinda tight right now!!

sapman

Thanks for the replies, guys! Probably it's uncommon around here because there are relatively few A8s in this neck of the woods.

Tim

TSHong

My thoughts exactly. Tstat is a common failure for all types of cars, even Audi A8.