Leaking thermostat housing (What am I doing wrong?)

I had a Stant Superstat that was .002" oversized and wouldn't sit into the recess all the way around. It didn't slip down and it looked seated when viewing from the top. Cracked two housings before finding the bottom edge was ever so slightly catching the outside. Inspect the fit of the thermostat in the recess before handling the housing.
 
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Mike Z said:
View attachment 360485
Is this what you are referring to?
Click to expand...

Get the Right Stuff 1-minute gasket maker. In 1-minute you’ll be back on the road. Tried 4 times to seal a TCase with no luck, cleaning it meticulously each time. One time with the Right Stuff and done. Tried 3 thermostat gaskets, two with RTV, one with none. Then used the Right Stuff. Done. I’ve never had it not seal the first time.

https://shop.advanceautoparts.com/p...buwb1oJNmpALI6vbK6hoCk_MQAvD_BwE&gclsrc=aw.ds
 
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RaymondT said:
I had a Stant Superstat that was .002" oversized and wouldn't sit into the recess all the way around. It didn't slip down and it looked seated when viewing from the top. Cracked two housings before finding the bottom edge was ever so slightly catching the outside. Inspect the fit of the thermostat in the recess before handling the housing.
Click to expand...

That recess is clean now. I did find a bit of hardened RTV in there so that may have been the culprit.
 
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I did mine five times before it stopped leaking.

Eventual solution was new thermostat housing...220 grit on a block to lightly sand bolt surfaces after the usual razor blading and cleaning.

No gasket. Put on the RTV, tightened the bolts fingerish tight, let it sit 24 hours to cure, then torqued it down.

Betcha that 1 minute right stuff would accelerate the process.

-Mac
 
There are a lot of recommendations for the OP to use RTV or the Right Stuff to seal the area that is leaking.
While these recommendations can work; the OP needs to find where the problem is and resolve the leak instead of using these two sealants to mask the problem.
As I posted in response #19.
"Use a Felpro gasket with the impregnated sealant on one side and the adhesive on the other; you shouldn't need to use RTV if the surfaces are thoroughly cleaned and there are no deep scratches or cracks in the mating surfaces.
I am sure I will receive flack from some forum members, but over the long term it is the right approach to resolve the problem.
 
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CharlesHS said:
There are a lot of recommendations for the OP to use RTV or the Right Stuff to seal the area that is leaking.
While these recommendations can work; the OP needs to find where the problem is and resolve the leak instead of using these two sealants to mask the problem.
As I posted in response #19.
"Use a Felpro gasket with the impregnated sealant on one side and the adhesive on the other; you shouldn't need to use RTV if the surfaces are thoroughly cleaned and there are no deep scratches or cracks in the mating surfaces.
I am sure I will receive flack from some forum members, but over the long term it is the right approach to resolve the problem.
Click to expand...

I have no disagreement with you. If the OP has "deep scratches or cracks in the mating surfaces" or other significant imperfections, then addressing those concerns is warranted. I was merely replying to the OP that I had an issue when installing my new thermostat that the t-stat kept slipping out of the recess in the housing and I used a tiny dab of RTV to keep it in place.
 
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I am not the mechanic I think I am.

Cleaned the mating surfaces carefully with a scraper, then with a scotch rite pad and mineral spirits, then a clean rag and acetone. Here's the engine side:
20220920_164724.jpg


I think I need a new housing:
20220920_165050.jpg


Pasted in the thermostat with a little RTV. I'm still not sure it is seated correctly:
20220920_165350.jpg


Finished product. I didn't take pics of The Right Stuff bead because it was so messy I am embarrassed. If anything, I used too much:
20220920_172031.jpg


Poured my antifreeze mix back in an immediately saw a drip, appears to be coming from the bottom of the housing. I spread some RTV on the bolt threads before installing.

I think it's time for a professional. I suck.

ETA: Thinking maybe it's the bottom bolt. I searched for a new replacement. Discontinued. Damn.
 
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I would not call that head surface or thermostat seating area clean, but that’s just me being anal and there are divots on the lower section of the thermostat housing mating surface where the temp sensor is inserted.
 
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You should hunt down a replacement housing that one might work with enough sealant but I wouldn't put it back in. The engine side can be cleaner and it looks as if there may be a couple of scratches, left of the bottom bolt hole. A mechanic with a diegrinder and the right brush on it, will get the surface as clean as it can be with doing any damage to original metal.
 
diggerwolf said:
I am not the mechanic I think I am.

Cleaned the mating surfaces carefully with a scraper, then with a scotch rite pad and mineral spirits, then a clean rag and acetone. Here's the engine side:
View attachment 360960

I think I need a new housing:
View attachment 360961

Pasted in the thermostat with a little RTV. I'm still not sure it is seated correctly:
View attachment 360962

Finished product. I didn't take pics of The Right Stuff bead because it was so messy I am embarrassed. If anything, I used too much:
View attachment 360963

Poured my antifreeze mix back in an immediately saw a drip, appears to be coming from the bottom of the housing. I spread some RTV on the bolt threads before installing.

I think it's time for a professional. I suck.

ETA: Thinking maybe it's the bottom bolt. I searched for a new replacement. Discontinued. Damn.
Click to expand...

If this were my Jeep, I would think about a new housing as well. I wonder if the imperfections in the housing where the coolant temperature sensor sits could be the issue? Looks suspect to me.

At least where I am located, Amazon offers free delivery for Prime members overnight. Could have it tomorrow AM.

Genuine Mopar Thermostat Housing 53006192-Amazon​

Visit the Mopar Store
4.4 out of 5 stars 51 ratings

$43.74
 
On the head, it looks like there is remnants of RTV or something in the depression that the thermostat sits in, at the bottom. Get all of that out of there. A razor blade or a pick should do it. Use a straight edge to check to see if the mounting surface of the housing nice and flat, or just get a new housing.

The last time I did this, I stuffed a rag in the head and used one of those Roloc scotch bright pads on my right angle die grinder to clean the surface, then vacuumed any dust/debris before pulling the rag out of the head. I used a new housing because my original had what looked like pitting on the neck. Also used a Felpro gasket with no kind of sealant.

One think to check too, make sure the bridge of you thermostat is not hitting the inside of the housing and keeping it from sitting flush with the housing. Sounds odd but I came across this with a Stant Superstat that I drilled a small hole in the flange to help with getting the air out of the system when filling with coolant. I didn‘t pay attention to how it all fit together and just drilled. The bridge was so tall compared to the MOPAR t-stat that it hit the inside of the housing if not in just the right spot.

https://wranglertjforum.com/threads/an-observation-of-the-stant-superstat-thermostat.29295/
 
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I did mine last week. I went with the 195F Stant thermostat with the Feltpro gasket. I used a razor blade to get most of the old gasket off. Then I followed that with the rough side of the scotch pad. Took these while I was in progress.

Keep us updated. Hoping it is something simple.

DBFB6C95-860A-4F57-8B0B-B07F1FCA20FF.jpeg


22892B55-A1CE-446F-9401-1E34B0556F44.jpeg
 
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