Thermostat housing problems

3938 Views 24 Replies 12 Participants Last post by walkerjay, Jul 11, 2012

bulldoguk

Discussion Starter · Jun 29, 2012 (Edited)

Thermostat housing problems - Fixed!

I have a problem with coolant leaking from the thermostat housing. The car came with a chrome-plated, o-ring sealed housing, which I have replaced with a standard, flat bottomed, cast housing.

I installed it with blue RTV on the intake and on the gasket that came with the housing. I let it dry, finger tight for one hour and then tightened the bolts down a half-turn. I waited 24 hours to fill it back up.

It still leaks once hot, I think it is from between the RTV and the gasket. Would I have better luck with just RTV or just the gasket? I have seen the silicon gaskets, are they any better? Again, with or without RTV? I should also mention that the intake was kinda rusty and pitted, so I did file it flat (but it still pitted) and cleaned it up with brake cleaner before assembly.

Thanks

1 - 20 of 25 Posts

Burke

· #2 · Jun 29, 2012

Check the housing and intake surfaces to make sure they are flat. Lap the surfaces. Use this gasket http://www.summitracing.com/parts/FEL-2202/
Don't overtighten the bolts.

sbc1320

· #3 · Jun 29, 2012

You could take a pick or a stainless brush and clean any pits as best as you can and fill in with some epoxy. File it down the next day.

Or just use the silicone. I just skim it on thin and bolt it up right away.

bulldoguk

Discussion Starter · #4 · Jun 29, 2012

Burke said:
Check the housing and intake surfaces to make sure they are flat. Lap the surfaces. Use this gasket http://www.summitracing.com/parts/FEL-2202/
Don't overtighten the bolts.

They have one in stock at my local autozone for $8.99, quite a but cheaper than $26.99 + shipping!

I'll give it a try, I might also try cleaning the surface on the intake up a little more as suggested.

Thanks

Philip

· #5 · Jun 29, 2012

The O ring type housing will seal if used with a gasket and the O ring.

As a general rule I do not use RTV on any gaskets. It is used in place of a gasket in non pressurized areas such as the ends of the intake and differential cover.

sbc1320

· #6 · Jun 29, 2012

I don't do the chrome(made in Japan or any others) housings at all. I just buy the heavy iron one from local auto parts and paint to my desired color.

dknova

· #7 · Jun 29, 2012

housing leaking

Just a thought, make sure the bolts aren't bottomed out in the intake.

bulldoguk

Discussion Starter · #8 · Jun 29, 2012

The chrome unit was junk, it wouldn't seal up at the hose properly, due to a lack of the large, rounded edge that the new, cast unit has.

Looking at the gasket in my hand, I am still kinda sceptical about it. It is really hard to get a file into the area due to other raised sections of the intake getting in the way. Fingers crossed that I can file it flat and get the gasket to seal up.

sbc1320

· #9 · Jun 29, 2012

bulldoguk said:
The chrome unit was junk, it wouldn't seal up at the hose properly, due to a lack of the large, rounded edge that the new, cast unit has.

Looking at the gasket in my hand, I am still kinda sceptical about it. It is really hard to get a file into the area due to other raised sections of the intake getting in the way. Fingers crossed that I can file it flat and get the gasket to seal up.

Last chrome I used was over 25 years back and it's in the field where I threw it by my old house. When I looked inside it had "Made in Taiwan" stamped on it. Put it against a flat piece of glass and it was warped big time.

Vinco

· #10 · Jun 30, 2012

Your only hope might be to put the mating surface of the housing on a belt sander for a bit to true the surface. The chrome on the mating surface needs to go anyway.

bulldoguk

Discussion Starter · #11 · Jun 30, 2012 (Edited)

2

The chrome piece that came with the car was also stamped "Taiwan". It currently resides in the trash can, I have no plans to use it and will be going with the cast (non-ferrous, so I assume aluminum alloy?) unit that I already have been trying to seal. It seems to be pretty flat already, the pitted, uneven intake is the main problem

I'm not used to dealing with cast iron engine parts.

The new housing from O'Reilly:

New Fel Pro gasket:

See less See more

tx71nova

· #12 · Jun 30, 2012

i have the same one on my car and it leaked but that was because the bolts were bottoming out just before it got tight enough to seal it.

also you can color the bottom of the housing and the mating surface on the intake with a black sharpie and then block sand both of them until all the black is gone.

sbc1320

· #13 · Jun 30, 2012

bulldoguk said:
The chrome piece that came with the car was also stamped "Taiwan". It currently resides in the trash can, I have no plans to use it and will be going with the cast (non-ferrous, so I assume aluminum alloy?)

I prefer the heavier cast iron one at Oreilly's myself.

superguy

· #14 · Jun 30, 2012

Did you use RTV on both sides of the Tstat gasket or just one?

I would tighten the 2 bolts more than finger tight to make sure the sealant gets a good seal and not wait so long to torque it to spec. Then wait 12 hours and drive it for awhile and pop the hood and re-torque it. Then when shes cooled off, re-torque it again and you should be good to go on leaks. It works for me.

68ctnovabb

· #15 · Jun 30, 2012

Had the same issue with cheapo chrome one as everyone. Kept getting worse until this spring when I walked back to my car at a show and the whole intake was drowning in coolant.

Splurged on a billet alum housing with the o-ring and never had an issue again.

No rtv or sealant needed.

bulldoguk

Discussion Starter · #16 · Jul 3, 2012 (Edited)

sbc1320 said:
I prefer the heavier cast iron one at Oreilly's myself.

They didn't have a cast iron one at O'reilly, just cast aluminum. Perhaps they stopped selling them, there isn't even one on their web site.

I went with the epoxy suggestion, covering the whole rim of the outlet on the intake with JB Weld and waiting until the next day to block sand it. I then used the aluminum housing with the Fel Pro PermaDry gasket. I also placed a washer under one of the bolts that may have been a little long. I'm happy to say that I got the motor warmed up and no more leaks!

For $8.99 I think the gasket was a pretty awesome deal.

Thanks to everyone for the help, I probably wouldn't have thought about the epoxy solution. Hopefully the epoxy holds up long enough at least until the next thermostat change.

sbc1320

· #17 · Jul 3, 2012

bulldoguk said:
They didn't have a cast iron one at O'reilly, just cast aluminum. Perhaps they stopped selling them, there isn't even one on their web site.

I went with the epoxy suggestion, covering the whole rim of the outlet on the intake with JB Weld and waiting until the next day to block sand it. I then used the aluminum housing with the Fel Pro PermaDry gasket. I also placed a washer under one of the bolts that may have been a little long. I'm happy to say that I got the motor warmed up and no more leaks! For $8.99 I think the gasket was a pretty awesome deal.

Thanks to everyone for the help, I probably wouldn't have thought about the epoxy solution. Hopefully the epoxy holds up long enough at least until the next thermostat change.

Yes they do, you just go one of the typical counter people is all.

http://www.oreillyauto.com/site/c/detail/MRY0/84823.oap?ck=Search_84823_-1_-1&keyword=84823

bulldoguk

Discussion Starter · #18 · Jul 3, 2012

sbc1320 said:
Yes they do, you just go one of the typical counter people is all.

http://www.oreillyauto.com/site/c/detail/MRY0/84823.oap?ck=Search_84823_-1_-1&keyword=84823

That's the part I got, it's made from cast aluminum now . . . . :turn:

sbc1320

· #19 · Jul 3, 2012

Bought that one a year or so back, maybe two and it's cast iron. Either one works though. I have filed a few of the Ford - 300(6 cylinder) engines as they are aluminum too. It won't warp like the "Made in Taiwan" will as these are made more rigid. Glad you got it fixed.

Is your part number the same as the one I posted?

bulldoguk

Discussion Starter · #20 · Jul 3, 2012

They also might have some old stock out there too that's made from iron. I could have asked them to bring all of them out and picked out an iron one. Like you said though, it's solidly built, especially compared to the one that was on there, you can really feel the difference.

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