Buddy of mine and I just finished replacing the headgaskets on his 2002 dodge ram 2500 5.9L. (Blown gaskets, coolant mixed with oil). Made sure everything was torqued in correct sequence and specs. Even flushed out his coolant lines and radiator when we were done.
Came by today for us to change the oil and finish rebolting on the exhaust. Got that all done, took it for a test drive. Noticed we've now got a knock after we did the oil change, when there wasn't a knock last night when we started her back up to make sure she ran. And while driving he's still having oil pressure drop when he's not on the throttle. Any thoughts on what we need to do?

 

Gas or diesel?

It isn't uncommon for bearings to get wasted when the oil is contaminated by coolant....

If oil pressure drops to zero at idle with engine warm, but, jumps up to 20 or so if you barely touch the gas, that's a bad oil pressure sensor.

 

2002 2500 5.9 is automatically a diesel and it's a 2nd gen.

 

Automatically a diesel? Why?

 

I could be wrong about this, but weren't the only engines available for the 2002 HD's (2002 1500's were first year 3rd gen) the V10 & the Cummins? Regardless, it's still a 2nd gen.

 

I don't know.... the 5.9 was still available in the third gen 1500's, at least.... for a year or so. Can't imagine that wouldn't have 'em in the last of the 2nd gens...

 

Into the first half of 2003, then it was replaced with the 5.7.