Hemi came in yesterday with an intermittent misfire on cylinder 8- checked the misfire counter and could watch misfires happening on the right bank consistently. Customer informed me the truck had just had head gaskets at another shop in town. I thought maybe the head was leaking and checked the coolant for exhaust gases, but got nothing. Pulled a plug, and it was heavily fouled and had carbon tracking up the insulator. Replaced plugs, wires, and COP boots thinking that was the problem. Nope- still has a light misfire. 90% of the misfires are coming from cyl#6, with a few randoms from 1,2,4, and 8. I swapped cyl #6 coil with cyl #3, and cyl#6 still has a mis.

Pulled #6 plug and found it was fairly oil soaked, after running for roughly ~45 minutes. Thinking this may be related. Are these hemis known to use oil? Valve seal? Intake manifold?

J.B. Chapman
Owner/Shop Foreman
Chapman's Automotive
Craig, Colorado, USA