88Mariah
05-26-2020, 02:05 PM
I have an '88 Mariah with a PCM 7.4L RWI. I was doing some routine maintenance this spring and decided to replace the t-stat while I was replacing the impeller and other items. So far I have ordered 2 different stats (at $100+ each) and neither one fits (RP026001 and RP026003). Both are too large in diameter and too thick to seat in the housing. I am the second owner and I personally know the original owner and know he did not change the housing. The old stat was working (yeah I know - not broke don't fix it), so I put it back in with a new gasket and now it won't close. I can't get it above 120 degrees. Anyone have a similar experience?