A6 Quattro

Check Engine Light and/or Engine Overheating Due to Failed Thermostat on Audi A6 Quattro

Problem Description and Possible Solution

The thermostat may erratically stick open or closed. The can result in illumination of the Check Engine Light and/or engine overheating.

Problem Data
RepairPal Verified
Average mileage: 88,849 (9,700–145,000)
Engines affected: 2.8L V6, 3.0L V6, 3.2L V6, 4.2L V8
14 model years affected: 1997, 1999, 2001, 2002, more2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012
49 people reported this problem
Viewing 1 - 15 of 15 comments
Overheating ...started when going over Vail Pass so high elevation and cold temperature. Coolant light went on...said to check coolant and torn engine off. I checked and the coolant was just below the minimum line. Added coolant. Car continued to overheat. Now waiting for repair shop to open tomorrow. Fan is working. Perhaps the thermostat? Is that a relatively easy and inexpensive repair?
Water start to boil in the reservoir , the thermostat goes to the middle and then down, last year replaced water pump and thermostat, very costly here in miami, what could be happening?
Just starting to hear odd..humming noise on and off. The temperature gauge will move beyond 1/2 mark..and move up to H mark..and say " turn engine off Immediately". Some days its okay, other days its not. Pump failing and/or thermostat sticking. I cant think of anything else.
While driving down the interstate at light cruising speed (70 mph) with cruise control active, I received a warning that my coolant temperature is too high and to let the engine run with my vehicle stationary. My car has been trouble-free since it was purchased new. I was told my a local German car aftermarket specialty shop that they have seen this to be a common problem. Not sure if anyone else has had the same issue with a C7 A6 3.0T Quattro.
Thermostat is faulty. Was replaced three years ago as part of a factory recall. Problem has resurfaced. Cost is ~ $1,000 because thermostat is located beneath the supercharger and replacement is "labor intensive."
While driving the thermostat sign appeared on my dashboard and smoke started to be seen on my hood. Had to park and have it towed to the nearest Audi dealer. The following day the dealer replaced a failing thermostat free of charge covered by my warranty. Just a hassle getting the fixed in between work.
Not overheating, yet... engine light on... shop says need new thermostat...$940 because so labor intensive. Help!!