Hey all,

I am running out of things to check regarding my intermittant low power. I suspect a head or head gasket problem may be the root cause. I am going to check a few more things first but in my experience the least likely and very expensive is what makes the problem go away. I have done head work on Mercedes diesels with aluminum heads before but never a Cummins.

From reading on here, I should pull the head and have it milled. Which head gasket should I use? Stock size or thick? Should I replace all the valve springs? The valves themselves? Should I replace or re-use the existing head bolts? Are they stretch bolts?

Any comments or suggestions are welcome.

Thanks,
Brian

 

Check the head for flatness before having it milled. Most of them are flat enough for re-use. If you are keeping the truck stock or close to it use the stock gasket unless you need to have the head milled. See https://www.dieseltruckresource.com/...95&postcount=6 for specs.

You can check the valve seats by laying the head upside-down and pouring a light solvent like mineral spirits or lacquer thinner in the combustion chambers and leaving it for a few hours. Leaky ones will empty the chamber. At your mileage I doubt there are any valve or spring troubles. If you plan to add an exhaust brake or really spin the engine fast this would be a good time to upgrade the springs, but otherwise leave them be.

Cummins has a bolt stretch guage made of high-tech cardboard. Cummins also says you can check the bolts by dropping them head down on a concrete floor. Bolts that ring are OK, ones that don't should be replaced.