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Welcome, I'm Chris (aka Moose).
Can you tell me the compression reading you get on each cylinder?
Compression can be off now after the repairs from
Once I know the compression I will be able to tell if the focus needs to still be on internal engine or if we can move to outside the engine checking other things.
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Those pressures are BAD.
Net step add 1 teaspoon of engine oil to the cylinder and recheck the compression. If you get a significant difference meaning a higher reading then there is piston ring or cylinder wall damage. Bring any of the lowest cylinder to TDC compression. Apply 100psi compressed air to the cylinder with your compression tester hose while another holds the engine from spinning with a wrench on the crank pulley. Feel for air blowing out the throttle body or exhaust meaning out of time or valve issues. Air blowing out the oil fill cap would mean rings.
It is not just 2 out 3 per bank bad. Minimum is 115 and average/good is 165 psi.
We will know more once these tests are done to see if the concern is in the block side or in the heads side.
Hello again Chris here,