whats the deal with mopar thermostat housings?

-
Some aftermarket intakes don't have blind holes for the bolts, so what you think is a housing leak, is a leak around the bolts.

On mine, I put teflon tape around the bolts and just use the gasket, no silicon, no problems.
 
I thought I had this problem licked with a new t'stat housing (pot metal, not chrome) from Advance Auto, with a new FelPro gasket and Permatex silicone gasket sealant. After 500 miles I began to get a slow antifreeze leak around one of the bolts. What a nuisance.

So, I dropped in 2 GM coolant system sealing tabs and drove the car 20 miles. The leak has stopped- for now.

For anyone wondering if these tabs are harmful to cooling systems- GM installed them at the factory in trucks in the 1990's and required they be used with every antifreeze change. I always used them in a '95 Chevy van and never had a spec of cooling system trouble in 13 years.
 
The only fix I've found for the chrome ones is to take the thing to a machine shop and have the sealing face machined flat, actually I do it myself at a freinds shop. The machining process also leaves a slightly rough finish to also help sealing. BTW when they're new they're not even close to being flat.
 
I use orange RTV silicone only.
Put and 1/8 inch bead on the neck only and slap it on there wet, wipe off any that squeezed out with a rag while it still uncured.
You will have to put a small bead of it on the surface of the neck where the thermostat seats to hold it there while you put the neck back on.
By the time I fill it with water, it's ready to drive.
I use orange RTV only on my XR500 Honda side covers too (Never leaks a single drop)
You do have to know how to apply it for what you are doing though.

And I HATE seeing it squished out and and not cleaned up, like some people do.

On valve covers I use the rubber gaskets with RTV lightly coating both side of the gasket.
Put it on the car wet, and cinch em down normally.
You will NEVER see a valve cover leak again.
I did this with my roadrunner and just to prove to a friend how well it works, I pulled all the cover bolts out after a day and drove it to his house 7 miles away.
Opened the hood and no valve cover bolts, no leaks either. (Not kidding one bit)
 
Trailbeast:

I know what you mean about the orange silicone. My new Chevy van came with leaking valve cover gaskets and that's how the dealer repaired them. Never leaked again in 13 years.

I did use a silicone sealant on the t'stat housing, but the leak came up around a bolt head (sealant was also applied to the bolt threads). Those bolt holes look like they do not go into the water jacket, but I wonder...
 
yarcraft91 said:
Trailbeast:

I know what you mean about the orange silicone. My new Chevy van came with leaking valve cover gaskets and that's how the dealer repaired them. Never leaked again in 13 years.

I did use a silicone sealant on the t'stat housing, but the leak came up around a bolt head (sealant was also applied to the bolt threads). Those bolt holes look like they do not go into the water jacket, but I wonder...
Click to expand...

for sure, but I don't think they do.
Probably just getting to the bolt from the little area between the thermastat and the bolt hole.
 
You must log in or register to reply here.
-

Back
Top