OK gang,Sorry i havent been on for a few due to technical situation.OK simple.I had my water pump go on me on the way back from the beach last wed.After replaceing the pump with the how toos on this site.Every thing went well.Today i started the 91 4.0 up and while every thing looked great,my temps were getting to near 240 before the thermostat or not would kick in.At 240 i started wacting the motor when i noticed a slight leak from the lower part of the Thermo housing.The temps never went above 240 however the spray was evedent enough to remove the housing and re install the original thermostat unit thinking i may have purchased a junk dura last unit.Well without gaskget material i glued up my thermo housing with water pump sealant and tried again.Instant fluid leakage from the housing.,,,,,,Tomarrow i will buy 2 gaskets and run a fat bead along my housing to try to fix.Question is,,do thermo housings warp,should i get a new one?Both surface areas were spotless before installation however the razor blade gap can surly be seen from my eyes after the second attempt.

 

you shouldn't need or use sealant on the t stat housing, or the water pump. simple gasket that came with is all you need.

 

,,so its looking like a warp issue?

 

not to insult your intelligence, but was the t-stat installed upside down?
again, with all do respect, it's been known to happen. sounds like it to me tho.

 

i'm a little confused at this part. was this your second attempt. have you put the t stat on with just the regular gasket? even if that leaked it could've been over or under tightened or a bad gasket. autozone doesn't always give you good stuff, to put it as nicely as i can, you end up wasting time with junk parts sometimes.

maybe get a real part at a real parts store

 

Yes,the first time i used a fel-pro gasket with a little sealant to keep in place,My second attempt i figured the new thermostat was junk and replaced it with the one i was running.I had no fiber gasket so i used sealant.Still confused as to why my temps were so high,normal is just under or around 200 in my current winter season here on the east coast

 

Do you mean the houseing,no,its outlet pointing towards the passenger side

 

no mang, i mean the thermostat.
the spring side should be down. it's very easy to install it with the spring facing up. fits no different, just won't open.

 

Get a new gasket. Also while you're at the store get some sand paper or emory cloth. What you need to do is put the sandpaper on a flat surface and rub the gasket surface of your T-stat housing on it until you have shiney metal all the way around. The T-stat housing is aluminum and it warps very easily. Anyhoo, this will regain your flat gasket mating surface. Just use your new gasket and a little bit of your T-stat sealant and put it togther. Make sure you torque it to OEM spec so you don't over tighten or under tighten. This will fix your problem.

 

the t stat housing was only like 15 bucks when i did mine you might want to replace it to make sure you have a straight unit to begin with. and get a good replacement t stat i went with a 180 degree unit i think it cost like less than 10 bucks but is was a good unit my jeep never gos past 220 and that is in the summer when it is like 100 out make sure to flush and refill your rad as well and replace the hoses this way you don't have to mess with it again for a long time

 

^ your jeep shouldn't go anywhere near 220 even with a 195 t stat, much less a 185. and some people are ok and some are not going with the cooler t stat. the engine is designed for a 195 t stat, for emissions and computer functions. its best to keep it that way, unless it doesn't see much street time.

 

Sorry for no reply,,i bought a new housing,Worked like it should.My temps are steady at just a little under 200.

 

i didnt read the whole thread but the t-stat on renix engines does need the gasket in there it gives just enough room to get the t-stat in there and sealed i learned this the hard way to.