I've finally solved my cooling woes (thanks eric) but now my thermostat housing has been leaking more then usual. the guy at the local parts store told me i don't need a gasket to fit between the edelbrock performer intake i have and the mr. gasket t-stat housing, just a rubber o-ring. Is he right? I'm currently using a stock intake gasket (even though it's a little too big) so i guess that'd be the reason for the leak?

The shiny chrome mr gasket t-stat housing has a rubber o-ring and a groove in it for such.

OEM thermostat housings use a gasket and sealant.

I've had only minimal luck with either style ;)

The chrome ones usually won't seal with a gasket. They're too weak to take the torque needed to seal a traditional gasket and they warp, too. Go back to the traditional style water neck with a gasket or get a fresh chrome one with the o-ring. If you go with another crome one DON'T over-tighten the bolts- just snug is all it needs to seal an o-ring. Any more and it just distorts the housing and causes a leak.

The shiny chrome mr gasket t-stat housing has a rubber o-ring and a groove in it for such.

OEM thermostat housings use a gasket and sealant.

I've had only minimal luck with either style ;)

Believe it or not, I use both and I have zero problems. I did it out of pure curiosity, and it worked out.

I'll add this- I run the chrome cheapies all the time. Only on rare occasion have I had one leak. The intake manifold can't be buggered up or pitted or you'll never get a narrow o-ring to seal up. I also use a fresh o-ring every time I reinstall it (unless I'm stranded in a parking lot or something) and again, I NEVER apply any real torque to the bolts. Once the housing hits the intake I only give it the slightest torque beyond that point- so little most people would probably be uncomfortable that it wouldn't stay tight. And if it's the slightest bit warped (check by laying it flat on some plate glass) it gets pitched in the trash and replaced with a new one. No big deal since they only cost all of $5.

Factory-style thermostat housings I've never had a leak unless the housing was warped or the intake was buggered up. They are a tried-and-true piece that rarely gives trouble if it's in good condition and properly installed.

I've had good luck with the o-ring type. One thing that can be done to help sealing the chrome ones which use a gasket is to sand the sealing surface. Put some sandpaper on a flat piece of glass and sand the surface of the housing in a circular motion. Spray the paper with WD40 or something similar to keep the paper from clogging. It might take a while to remove the plating, but it works.

I use a shit load of silicon, works fine every time. lol

I have a Mr. Gasket thermostat housing with the rubber o-ring. I didn't use any RTV the first time I installed it (with a 180 stat), and it didn't leak. I also didn't use any when I changed the stat to a 195. No leaks here - maybe I'm just lucky.

thanks fellas thats all i needed to know.

So what's the deal here then.. am I either the only guy here with the guts to admit he can't get these damn things to seal or am I dealing with some seriously shit parts?

I tried time and again to get the mr gasket thing to seal.. used COPIOUS amounts of RTV.. even switched to coolant specific gasket maker.. and just had coolant welling up around the bolts like theres no tomorrow.

At some point in this process I stripped the threads out of one of the holes and put in new threads too.

Went to the old iron housing, paper gasket, copious quantities of rtv, and again, still comes up around the bolts. Not so bad now, a year later, but then again it's not as clean now and harder to tell.

What the heck guys?

On most intakes, the thermostat housing bolts go into water. Use something on the threads to seal them from wicking water up to the top. I normally use some type of thread locker that has Teflon in it. This will seal the water passages as well as keep the bolts from galling and getting stuck in the manifold. Good luck.

I will scuff the bottom of the chrome outlet and use gascacinch with a paper gasket. felpro 35562t is the permadry version its pretty good never had a problem with it

I've had good luck with the o-ring type. One thing that can be done to help sealing the chrome ones which use a gasket is to sand the sealing surface. Put some sandpaper on a flat piece of glass and sand the surface of the housing in a circular motion. Spray the paper with WD40 or something similar to keep the paper from clogging. It might take a while to remove the plating, but it works.


That's what I did with mine and never had a problem in almost 9 yrs. If I had to pull the intake I wouldn't take the T-stat housing off just the hose.

Felpro 2202 Tstat gasket with the standard housing. You will never have a problem again.:)

http://static.summitracing.com/global/images/prod/norm/fpp-2202_w_m.jpg

I Second the Fel Pro but it can have problems when using the O-Ring style housing with this O-ring Gasket.

This gasket is best suited for standard style housings and is reusable for many years!

I must be lucky; no leaks after putting the Mr. Gasket O ringed stat housing on twice!

well i took the t-stat housing off today, got rid of the old gasket/sealer/coolant mush and installed the correct o-ring. Fired her up after and so far so good! I'll keep an eye on it over the next while and if doesn't leak at all, i'll really be impressed.