So I replaced all heater and radiator hoses and figured I'd put in a new thermostat at the same time on my kid's '92 XJ 4.0. Does anyone have a trick to keep the thermostat from moving/shifting while putting the housing back on? I've put it together 3 times and each time it leaks. I'm applying plenty of sealant, but I still think the thermostat is moving. Not sure which engineer thought putting a side mount thermostat was a good idea. Thanks!

 

Put a small blob of thread sealant or water pump gasket sealant on the lip...press tstat in, make sure its seated in thin groove. Let dry for 10 min then install housing. Thoroughly inspect housing to make sure you didnt crack it yet. It might help to remove hoses from housing so you can seat it easier

 

How much torque are you putting on the bolts? Have you checked that the housing is not warped?

 

The housings crack pretty easily, been there done that. You may want to check your housing for a hairline crack.

 

I have had good luck with a real gasket and a thin coat of sealant even without beautifully smooth surfaces. Also, the factory torque spec isn’t vey much.

 

While awkward it can be done.
Without gunk.
Cause I used a FelPro gasket there instead of the supplied paper one and they said to not use any.
IMO the channel that the thermostat sits in needs to be super clean.

 

Like others have said, be sure the housing isn't cracked from your first installation. Mine was not seated right the first time and with just " one more" turn of the wrench... cracked!