[Russell A Hawkins]

I also have a 5.9 intermident miss on #6 under load, it drinks coolant so I know there is an issue, when I got the vehicle it missed at idle pretty bad when hot so I decided to make it so it wouldn’t build psi in the system by removing the psi seal on the rad cap and it completely fixed the miss at idle so I’m thinking bad head and there is also some oil in the plenum which I’m not surprised since it has 235k, the confusion I’m having is it will run great all threw the pedal for a few days or so then all of a sudden it will slowly start to miss and then keeps getting worse and there’s been times where it’s running like ass and come to a stop and it’s running fine, all wires, cap etc are fine haven’t checked fuel psi yet, it doesn’t ping, no lifter ticks, it’s more than likely the coolant issue but the in consistency is baffling.

[Russell A Hawkins]

Make sure you have it at full throttle when checking compression

[Author]

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