Blown head gasket

2004 GMC SIERRA
106,795 MILES • 5.3L • V8 • 4WD • AUTOMATIC
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ROVIEZZY
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Coolant constantly dropping but no external coolant leaks.
New oil change of 5w-30 at 105,470 miles. I am only around about 106,800 miles and engine oil is very black and sludgy.
I was told viscosity is too old due to being an older truck and to use higher viscosity 10-40. So i did.
in terms of overheating problems or issues, none!
Removed spark plugs and passenger side plug #8 was drenched in oil. All other plugs looked very burnt with some oil.
Dec 31, 2019 at 2:11 PM
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SCGRANTURISMO
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Hello,

Does your vehicle have a lot of white smoke that smells sweet coming from the tailpipes? This would indicate that coolant is being burnt in your vehicle's engine's combustion chambers. Also, your vehicle's engine oil would look like coffee coffee with cream and sugar in it if coolant was mixing with the engine oil. However, you should not have oil on your spark plugs either. This could be a result of worn oil piston rings, bad valve guides/seals, or a cracks cylinder head or engine block high in the cylinder wall. I would recommend doing a compression test on your vehicle to see where you stand and where the problem cylinders are. Here is a link below explaining how to do one properly:

https://www.2carpros.com/articles/how-to-test-engine-compression

Please go through this guide and get back to us with what you find out. We can go from there.

Thanks,
Alex
2CarPros
Dec 31, 2019 at 4:15 PM