Qsx 15 Cummins

195 · Oct 29, 2023

The engine developed heavy blow by and then it looks like it started to blow oil out the back of the valve cover gasket. The head was just replaced with a reman. It also appears to have a lot of unburnt fuel coming out the exhaust at idle.

used red MN · Oct 29, 2023

How does it sound when you crank it. A cylinder with low compression will cause the crank speed to increase due to less resistance causing an uneven crank. With diagnostic software the tech can actually perform this test and it will report the likely cylinder if there is one with a problem. Remove the dipstick or oil fill cap and feel for pulses this would also indicate a cylinder problem. Obvious failures are broken rings, scored piston or liner, piston burnt down the side due to a poor injector spray pattern etc.

RodinNS · Oct 29, 2023

Probably a head gasket issue... I'd probably take it back to whomever put the head on it.

Rod

T in NE · Oct 30, 2023

Does it start cranking like the batteries are low, or the starter is going bad?
The isx is known for tipping liners. Means recutting sleeve counterbores and decking the block.

Qsx 15 Cummins

195

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used red MN

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RodinNS

Well-known Member

T in NE

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