2001 yukon denali 6.0 oil in cylinder 1 and 3

[tendempine]

I have a 2001 gmc yukon denali 6.0. I had taken my car to a mechanic to get a dionostic and he told me I have oil in cylinder 1 and 3. He said he cleaned out the oil and it came back when he started it. It runs with loss of power and has a random misfire code. Is there anything I can try before replacing my head gasket

 

[OR VietVet]

Welcome to the forum from Oregon.

Sorry about the problem with your truck.

Miles on the engine? Random misfire code for 1 or 2 cylinders are are/is for cylinder 1 or 3 or both? Oil in cylinder can foul the plugs. Were the same plugs reused when "cleaned out" and restarted? How was the oil cleaned out? Was a dry and wet compression test ran? If so, what were the results?

 

[tendempine]

Welcome to the forum from Oregon.

Sorry about the problem with your truck.

Miles on the engine? Random misfire code for 1 or 2 cylinders are are/is for cylinder 1 or 3 or both? Oil in cylinder can foul the plugs. Were the same plugs reused when "cleaned out" and restarted? How was the oil cleaned out? Was a dry and wet compression test ran? If so, what were the results?

The engine has 193k miles and I don't know how the oil was cleaned out and yes the same plugs where used. The code says random misfire and he told me it's for cylinder 1 and 3

 

[Marky Dissod]

Either the rings are letting oil in from the bottom,
or valve seals are letting in oil from the top.
How else would oil get inside a combustion chamber?

 

[OR VietVet]

Old plugs were likely fouled. Can cause a misfire, even if oil is not getting back in. Compression test, dry and wet, is needed.

 

[Mudsport96]

Either the rings are letting oil in from the bottom,
or valve seals are letting in oil from the top.
How else would oil get inside a combustion chamber?

Could be that the pcv system has flooded the intake manifold with oil and that is getting in the cylinders.