m750rider

1991 S4 auto

My engine temperature fluctuates with outside air temperature. When it was cool the engine would run cool, less than 140, now that it has turned warmer, it will run as high as 190, maybe even a little hotter in traffic. I bought a thermostat and O ring, but after reading more posts and the tutorials on 928intl, I am wondering if I should have also gotten a rear thermostat seal.

I have not checked the actual temp with an IR gun, so I don't know if the temperature gauge indication is accurate, but it is no doubt moving with air temp.

Do I have a partially open stuck thermostat, or is there something else going on?

I'm pretty new to this 928, you advice and experience is welcome.

Thanks

Bob

Mrmerlin

yes you need a rear thermostat seal , this part should be replaced if you remove the thermostat as its usually falling apart,
take a screwdriver and tap the outside edge of the seal into itself then it will pop out.
Tap in the new part with a properly sized socket turned around so the smooth side of the rear of the socket presses evenly on the seal,
an extension is usually required to be fitted to the socket