Vehicle is a 1987 740 turbo. So I decided to change my coolant and at the same time get a new T-stat for my 740 since I was having warm up issues, especially in cold weather. I got Part #2G0167 from ipd because I was told the warmer T-stat would be better. I drained the coolant no problem and refilled up to T-stat height. I then put the T-stat in and topped cooling system off. I could hear it dripping so I knew something was wrong. There was coolant leaking out around the T-stat housing. I realized I had put the seal in wrong, on top of lip on T-stat instead of below (boneheaded move). So I put it back in the right way and it was still leaking. I took it back out and compared it to the old seal that I had taken out. It was slightly smaller and didn't quite fill up the circle around the T-stat.

Has anyone else run into this problem or did I get the wrong T-stat? Also would the colder T-stat be better for my car since it has a turbo? The one I got is 197F/92C and the cooler one is 191F/88C.

Thanks in advance for any advise.
--
1987 744 Turbo 138,000 miles