Coolant leak

2004 CHEVROLET SILVERADO
174,000 MILES • 5.3L • V8 • 4WD • AUTOMATIC
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LAYTRON3030
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So lately I have been losing coolant rather quickly. I took it into a shop where it sat for days on 20psi and they could not find where it is going either. I have changed the reservoir cap as well thinking the seal went bad. I do not believe it is a head gasket either as the oil is not milky, and there is no visible leaks/drips anywhere. Could it be a manifold gasket? This is keeping me up and night and stressing me out! I am desperate guys! Please help.
Feb 28, 2018 at 3:04 AM
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HARRY P
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The intake gasket is a definite possibility. A fairly easy way to look for it is to pull a couple of spark plugs out. If they are really really clean looking, then you know coolant has been getting into the combustion chamber. Here is a guide on replacing spark plugs: https://www.2carpros.com/articles/how-to-change-spark-plugs

Also, just because the oil is not milky does not mean that the head gasket is not leaking. There is a very specific test that looks for exhaust gases in the coolant. Here is a how-to guide for it: https://www.2carpros.com/articles/head-gasket-blown-test

My opinion, you have got to run these tests. The one for a leaking intake gasket is free, so start with it if you can. Good luck and let us know what you find.
Feb 28, 2018 at 5:25 AM
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LAYTRON3030
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Thank you so much. I will get these done and let you know.
Feb 28, 2018 at 11:47 AM
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MIKE H R
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when the engine is cold it might not show a head gasket leak, when the engine is hot it expands some. that may be why the shop may not have found it. I agree that it may be a intake manifold leak. the other leaks would leave a tell tale sign of a leak if it was anything else. does the engine look dry in all the spots you can see?
Mar 3, 2018 at 7:23 AM
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LAYTRON3030
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Yep, completely dry everywhere. It went from the -40's and -30's to above 30 in a few days. Weather is rough on vehicles up in Montana, haha. Going to run an intake leak test today.
Mar 3, 2018 at 10:10 AM
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STRAILER
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Hello,

I have seen where the water pump will only leak when the engine is running can you confirm the weep hole is dry?

https://www.2carpros.com/articles/car-is-leaking-coolant

Please run down these guides and diagrams and report back

Cheers, Ken
Mar 5, 2018 at 1:05 PM