[RESOLVED] Permatex Thermostat Housing Sealant, to use or to not use?

[MikeT1982]

Hey guys, I have a 1997 Eclipse GS-T. I am going to replace my thermostat, the 2 bolts for the thermostat housing (bought them along with the stat from the dealer), and my upper and lower radiator hoses and clamps. I will use all OEM parts. Now I read the posts and searched and found that there is no gasket between the thermostat housing and the head in my car. However, I am wondering if I should place a thin layer of Permatex Thermostat Housing Sealant on the perimeter of the thermostat housing and make rings around the bolt holes. I am assuming I would NOT place any sealant on the stat gasket itself, just the polished metal surfaces of the stat housing that meet.

Or should I just wipe the surfaces clean and leave them bare? Any harm done with introducing some Permatex to the surfaces?

Thanks ahead of time!

- Mike

 

[turbosax2]

I use Permatex Ultra Grey RTV between the thermostat housing and head, and also the upper radiator hose pipe that sits on the top of the thermostat housing. You'll see there are grooves in the flanges for you to lay down a bead of RTV. After you clean off all of the old RTV, lay down enough RTV in the groove for it to seal but not so much that when you bolt them down the RTV squishes into the inside of the thermostat housing. You don't have to worry about making RTV rings around the bolt holes. The thermosat sits under the lower radiator hose pipe on the side of the thermostat housing. The OEM thermostat will come with a gasket attached so no RTV is needed; just pop the thermostat in and bolt the pipe back on. Make sure the jiggle valve on the thermostat is pointing up when you place it in the housing.

If you're just replacing the thermostat and radiator hoses, only the lower radiator hose pipe will have to be removed from the thermostat housing. Leave the thermostat housing and upper pipe alone if they aren't leaking. If you do decide to remove the thermostat housing for any reason, there is an o-ring between it and the water pipe that should be replaced.

 

[Bud92gsx]

Permatex is good stuff I use it on everything. Plus I have a bunch of free stuff they gave me..And some of the stuff is green, so IT's safe..

 

[MikeT1982]

Thanks a MILLION guys. Turbosax, thank you for such detail hopefully this post will help any others in the future who are questioning any part of the housing!!! I didn't realize each section was different. Thank you! Since the bolted part to which the upper radiator hose attaches is not leaking, and neither is the housing to head area, I will leave them alone. I'll just do the lower hose part and leave it dry (without sealant) and use the new bolts. Thanks man.