Originally Posted by Dougfuller
Based on this test, my mechanic, which worked for Cummins for 10 years
I question your mechanics basis.
My experience with Cummins is they do not publish a compression
number. To use in determining the health
of an engine. Instead they use a blow by test.
Now, I agree with your mechanic on the values of the compression against what you would see as normal. And in the same instance I to would recommend a rebuild