Did a valve adjustment on a 6.7 Cummins at 150k miles yesterday, the difference in sound was crazy

I mean I've heard people say it's worth doing but I didn't expect that much change. It was ticking pretty bad before, now it's way smoother at idle. My buddy told me to check the lash on the exhaust side first cause those always tighten up. He was right, three of them were at like .008 instead of .015. Has anyone else seen that pattern on the later model 6.7s?

3 comments

3 Comments

the_elizabeth17d ago

Three of mine were tight on the exhaust side too at 130k.

parker1833d ago

Did you try a different oil or just do the adjustment, @the_elizabeth? I ran MMO through mine for a few hundred miles before the job and it helped loosen things up a bit.

anthony_campbell883d ago

Exhaust side always tightens up first on these, common issue. Running a hotter oil before the next adjustment will help keep em from moving as fast later on.