I am helping my neighbor with his 2007 Suburban (230,000 miles) that is knocking. We opened up the valve covers and the rocker arms all felt good, no play at all. We were both shocked because it seemed the most common problem. We ended up pulling the heads to really look at he lifters and see if there was a flat spot on one of them, not willing to admit it is not a lifter.

Anyway that is were we are at now. Is there any way a lifter can look good but actually be bad?? We are going to replace them since we already have it torn down.

I am very open to any ideas of where to go next?

 

Welcome to the forum. You are in the right place here. Someone should have an idea.

 

Is it burning oil?

 

Yes it burns quite a bit of oil.

I also just noticed this on the heads when cleaning them up tonight.