looking to see if anyone else has had the same problem I have. I cant get my thermostate housing to seal for a distance. No matter what I do it devopls a leak after a while . I tried just a gasket, just sealer, and I let the sealer set up. Any tricks?

 

I use a gasket and sealer on both sides.
A heavily pitted housing or intake could
cause problems also. Make sure to tighten
them down evenly, going back and forth.

 

Is it leaking from the housing or wicking from the bolts?

 

Make sure it seats fully in the slot, too.

 

Its leaking where the gasket is. Alright I will try putting a gasket with sealer on both sides. Its just so frustrating.

 

This, or some form a gasket material like RTV.

 

Get like 80 grit sandpaper on a known flat surface, and scuff the gasket edge in figure 8's. Also a good idea to just snug it before tightening and stick your fingers down the hose end and see if you can tell if the thermostat is seated.

 

I am going to guess the housing is warped. If you have a good flat file, put the housing in a vise and run the file across the bottom of it. You might be able to true it up.

 

Don't forget that on some manifolds the bolts go straight through into the water passage. So what may appear as a gasket leaking could be a bolt instead. I put Permatex #2 (non-hardening) on the bolts and never have a problem.

 

agreed
one of very few Olds engine bolt holes that go thru into a juicy area.

Perhaps fuel pump to block, and water pump lower 2 quarter inch to timing cover, but their cavity is not pressurized coolant or oil.

 

Mine leaked around the bolts, too. I applied a liberal amount of blue RTV on the bolts and in the bolt holes, and that solved the problem for me.

 

Also check to make sure the bolts can thread deeply enough into the intake. Sometimes there is a bit of corrosion on the lower threads that prevents the bolts from tightening sufficiently to clamp the housing to the manifold. With the t-stat housing off, try running a new bolt or a tap all the way down to clean out the threads.

 

I'll assume this is not a chrome Tstat housing? Chrome ones seem to leak because they are too smooth.

 

This is another case where it pays to read the CSM. My 64 CSM (for example) specifically calls out thread sealer on the two t-stat housing bolts and the four large water pump to block bolts.

 

And they are made in China.

 

Go and get a good cast iron water outlet and pitch that pot metal thing in the trash.

 

Interesting
The two bottom SMALLER WP bolts go into the crankcase, sure, seal 'em.

But I am quite certain that the 4 larger WP bolts go into blind, sealed cavities.

 

The large water pump bolts go into blind holes. I just did this on my engine. Makes no sense to put sealer on them?
The two lower smaller bolts do indeed go into a area with oil but not pressurized as stated above. Those I put thread sealant on.

 

I have had the same issues getting them to seal. Good luck getting the cheap chrome necks to seal. I sanded my factory aluminum neck twice and used double gaskets with RTV on both sides to seal. I used teflon tape on the bolts too.