I found why my thermostat housing leaks

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Jim
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I found why my thermostat housing leaks

Post by Jim »

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The thing began to rust where the rubber gasket contacts the steel. As you see the pits were deep I smeared a little RTV on the surface before assembling it.
Best Regards, Jim
2004 Tahoe, Summit white, loaded up. 06 front air dam, wood interior trim, Shaved Roof Rack, Escalade rear vents, LED Tails, SLP dual cat back exhaust w/ Flowmaster 70 muffler, 20 inch 07 Sierra wheels.
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HenryJ
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Post by HenryJ »

Something is "fishy" here...why?

I can understand cheap aluminum housings doing that with poor corrosion inhibitor protection, but steel in under four years?

Was is really rust? Or could it have been electrolysis, corrosion, another oxidation other than rust.

Have you replaced/changed the factory Dexcool? How old what brand?

The reason is I have had my thermostat cover off a dozen times and have nothing even close to that happening.

I have been running the green for about two years now.

Any ideas on what can be done to prevent this?

I'm wondering what the water pump looks like? I'd imagine that the impeller is similar steel. I really doubt they used a nice cast bronze unit ;)

What do you think can be done to prevent this? Silicone is not going to be a permanent fix.

Buy a new one and powdercoat it?

"Speed doesn't kill, suddenly becoming stationary does." - Richard Hammond
"Speed is just a matter of Money - How fast do YOU want to go?"-Mechanic from Mad Max-
If at first you don't succeed - Don't take up Skydiving!
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Jim
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Post by Jim »

The truck is 2 years old & 4 months. This is my change in Dexcool time I am using 70% Prestone Orange & 30% distilled water. Having checked the pros & cons of Dex it seems if you change it every 2 years green or Dex I was told I would have the same results. I am wandering what the intake to head gaskets look like. Hopefully this outlet tube is crap metal, the pits were rust color I think it is rust. Others on the forum have had leaks but they had the dealer fix the problem.
Best Regards, Jim
2004 Tahoe, Summit white, loaded up. 06 front air dam, wood interior trim, Shaved Roof Rack, Escalade rear vents, LED Tails, SLP dual cat back exhaust w/ Flowmaster 70 muffler, 20 inch 07 Sierra wheels.
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HenryJ
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Post by HenryJ »

Could it have been moisture from the exterior (washing) trapped just to the outside of the o-ring leading to the leak after a while?

Seems like from what I can see it is right at the oring, like there was a little leak and the rust (oxidtation) started right at the coolant/air interface.

I wonder if the dex's sensitivity to air could be a contributing factor here? If that is the case, your heads and pump may be just fine since it is less likely they were exposed to the air.

Hopefully the change of coolant will solve the problem.

"Speed doesn't kill, suddenly becoming stationary does." - Richard Hammond
"Speed is just a matter of Money - How fast do YOU want to go?"-Mechanic from Mad Max-
If at first you don't succeed - Don't take up Skydiving!
- ThunderII KE7CSK