So, before I replaced my plenum gasket this last weekend, my thermostat gasket was leaking as well. When I got my car all back together it was still leaking so i pulled the housing again and put a lot of rtv on the gasket and then reassembled. It is still leaking out of the gasket and I have no clue why.

Does anyone have any advice or hints on what kind of rtv or sealant to use to stop that sucker from leaking?

 

There is a gasket for that not rtv, mine was leaking when I got it because some dumb@$$ over tightened the bolt and stripped the aluminum. Ended up using a heli-coil with a tap and die.

 

Which engine you got? if its the 4.7 make sure you put the gasket/seal in correctly, theres a tab on it that goes in one way on the housing. Not sure about the 5.9 or any other engine

 

Now if its a gasket it would be the blue rtv but im not too sure if its needed

 

It is a 5.9l, look in his vehicle info on top right part of his post.

 

Sorry on my fone wish i could see it.

 

There we go no more mobile theme lol

 

Ya, I've got rtv, then the gasket, then rtv on top and it still leaks. And the housing is in correctly with the tab on the front of the motor, but it still leaks.

 

I installed a Gates tstat that came with a paper gasket. I first aligned the tstat tab with the slotted channel in the housing, then pressed it in hard. Then I affixed both the tstat / housing to the engine water outlet with gasket as a single unit. Didn't use any RTV and didn't have any leaks either.

An afterthought - if the housing surface is slightly warped or a hairline crack exists - its not that expensive to replace. Maybe 10 to 15 bucks.

 

Could have been the rtv especially if you didnt let it sit before you added the antifreeze. Or you could check if the alignment is a bit off.