Help! I can’t stop my coolant leak.

[Rob Goblin]

Hey guys, I found a coolant leak from my thermostat housing two weeks ago. I bought a new housing because it had one of those chrome jobs on it. I replaced the thermostat, housing, and hoses, but when I fired it up, it started leaking again in the same area, maybe worse. So, I took it apart, bought another gasket, and used a ton of rtv because there was a ton on there before. My thought was maybe the intake has some imperfection I’m not seeing. I let the rtv cure for two days this time. When the thermostat opens it leaks. I’m at a loss and at my wits end as to what to do. No matter what, I’m going to have to take it apart and put another gasket in it. What can I do to stop it from leaking? I’m moving two hours away and I’d prefer not towing it. Pics of before I pulled and this morning. Should I put the old housing back on and try that?

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[jjester6000]

I think you got a cracked intake manifold around the housing.

If I were you, I'd try to find the crack, rough it up, and JB weld it for just for now.

 

[78C10BigTen]

That bottom one looks like its leakin out the pipe plug not the gasket. Id pull that plug and put pipe tape on it then tighten it back in first

 

[eskimomann209]

A better picture would be one with that housing off and mounting area cleaned. So we can see mating surface and help look for cracks!

 

[eskimomann209]

That bottom one looks like its leakin out the pipe plug not the gasket. Id pull that plug and put pipe tape on it then tighten it back in first

I’d die if it was the problem.

 

[QBuff02]

my bet is your leak is coming from the lack of pipe dope or pipe tape on those plugs on the thermostat housing itself. If I'm not utilizing the ports where the plugs are, I replace the thermostat housing with a smooth one. less holes is less places for leaks to form. dope the plugs or tape the plugs, tighten em up and I bet the leak disappears.

 

[Rob Goblin]

I know it looks like that, and I thought that at first, but I actually watched it drip from around the housing in the intake today. I will tape those up as well though. I think it was leaking there too but not as much as I saw from the housing and intake.

 

[Crispy]

Pressure test that thing if you havent. That way you can see where its coming from instead of a puddle. Aluminum intake though might be the cause with a previously overtightened bolt being the reason.

2nd on the pipe plug looking to be leaking in the 2nd pic.

Rip that housing off again, take it all apart, clean it all up, put it back together and let it set. Then pressure test.

 

[Poppy 87]

I don't ever use rtv on a thermostat housing

 

[Dutch Rutter]

I've started only using the more expensive o-ring thermostat housings. No gasket to mess with and no RTV needed, but does need the intake surface to be pretty flawless in order to seal correctly.

 

[shiftpro]

I’d die if it was the problem.

Well then will fix the truck?
A decent welder that can tig weld aluminum could fix it, if that's the case.

 

[eskimomann209]

Well then will fix the truck?
A decent welder that can tig weld aluminum could fix it, if that's the case.

A decent welder can weld aluminum. But it takes a little more than decent to TIG cast aluminum.( both the man and the machine.) The fun thing about aluminum is the cracks can and often are longer than they look. And this thing has channels in it. but it’s not my intake nor my truck.

 

[shiftpro]

A decent welder can weld aluminum. But it takes a little more than decent to TIG cast aluminum.( both the man and the machine.) The fun thing about aluminum is the cracks can and often are longer than they look. And this thing has channels in it. but it’s not my intake nor my truck.

Well then, thank you for the compliment! I must be beyond 'decent'! Maybe should raise my rates, hmmm..

 

[Rob Goblin]

Honestly, I hate that intake. Actually, I hate just about every modification the previous owners did to the engine. It’s all half-assed and rednecked together. Don’t get me wrong, I’m as redneck as they come, but I’ve never understood not doing something the correct way because in the long run you’ll just end up having to redo it anyway. I just need this motor to carry me a few hours away. I already have another engine in my lwb that’s way better. I’ve sourced another intake for this motor, but it’s going to be a bit before I can tear it down.

 

[Octane]

Hey guys, I found a coolant leak from my thermostat housing two weeks ago. I bought a new housing because it had one of those chrome jobs on it. I replaced the thermostat, housing, and hoses, but when I fired it up, it started leaking again in the same area, maybe worse. So, I took it apart, bought another gasket, and used a ton of rtv because there was a ton on there before. My thought was maybe the intake has some imperfection I’m not seeing. I let the rtv cure for two days this time. When the thermostat opens it leaks. I’m at a loss and at my wits end as to what to do. No matter what, I’m going to have to take it apart and put another gasket in it. What can I do to stop it from leaking? I’m moving two hours away and I’d prefer not towing it. Pics of before I pulled and this morning. Should I put the old housing back on and try that?

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Looks to me leaking at that plug