Saihtam

Hello everyone!

So, some background: When I bought this 2004 Audi A6 1.8T Quattro from the previous owner the thermostat had gone bad resulting in the thermostat not closing properly and leading to low engine temperatures.
One of the first things I did was to replace the thermostat, and after that the temperatures hovered around 90-92C consistently.

Fast forward a few months and I noticed that the coolant temperature suddenly started to stabilize at just short of 100C (97-99C).
I have driven the car like this for quite some time now and I haven't noticed any problems, but I'm wondering if this is a problem or if it's normal for the 1.8T engine? Bear in mind that the engine reaches this temperature no matter the outside temperature. It acts just the same now in -10C as it did a few months ago in 20C.

Any ideas would be greatly appreciated!

georgeb944

It might be a gauge problem, instead of a real temperature problem. If you have VCDS, you can monitor the temperature reported to the ECU. Other OBDII tools can also do the same. You can also use an infrared thermometer to see if the temperature reported is accurate. Of course, it could be the thermostat, too. although they tend to be fairly reliable.