Ok so my wife's truck developed some sudden and significant valve train noise. Not uncommon from what I have been reading. The " ticking" or in this case more like rattling was only on the passenger side of the engine, that became more of a whine when revved. I have removed the valve covers, and there is nothing obviously loose or broken
. I have pulled the plugs and again they look fine. Compression is between 150 and 160 on all 8 cylinders. 156 k miles. Some sludge is visible.
So here are my questions.
1 is this the lifters, or could this be a bad oil pump.
And how do I test the oil pump?
2 I'm going to do the lifters and camshaft any way. It's time. Do I need to replace the camshaft bearings, and rocker assembly's?
3 without doing a total rebuild what else should be done while I have it open?