Audi
2 Answers
Thermostat on that motor is part of the housing, it's one unit. That's a fairly complicated procedure, you need to put the nose in the service position and then go further in to get to it. I would verify that any codes you are getting related to the engine taking too long to warm up or getting too hot be verified against the dash gauge, and a scan tool with live temp reading. The coolant temp sensor can, and has been known to go bad on those cars as well giving false readings and throwing codes. YES the thermostat does fail. And here is what you are up against to chsnge it. https://www.pelicanparts.com/techarticles/Audi_B6 _A4/27-WATER-Thermostat_Replacement/27- WATER-Thermostat_Replacement.htm
You need to replace the whole housing. German cars are not simple $10 thermostat. FCPeuro has the current OE one for $66 with free shipping.