Disco II sudden valve train noise

[BugSplatter]

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?

[Disco Mike]

You should have checked our oil pressure first. That being said, and the engine apart, pull the front covers and inspect the pump, you most likely have a broken oil pump ring.
If you want some help on this, send me your number and I'll call you.

[BugSplatter]

I forgot a bit of info. It's is a 1999 discovery II, and the oil light never came on. I will let you know when I get to the oil pump.

[Disco Mike]

Read the 2 sticks at the top of the D2 section so you know what to look for regarding valve train noise.

[loganpendergraft]

What I thought was valve train noise on the passenger side only turned out to be a loose exhaust manifold. Might try tightening that before digging into the engine.

[BugSplatter]

Ok so I'm finally down to the oil pump and it all looks good. I did find that on the way into the engine that intake manifold,valve cover, and oil pan bolts were all loose or not torqued.

I'd
Is This timing chain too loose?

Any other thoughts before I order parts, and start re assembly?

[BugSplatter]

Ring gear photo.

[GreenGiant]

Originally Posted by BugSplatter

Ok so I'm finally down to the oil pump and it all looks good. I did find that on the way into the engine that intake manifold,valve cover, and oil pan bolts were all loose or not torqued.

I'd
Is This timing chain too loose?

Any other thoughts before I order parts, and start re assembly?

Timing chain slack reminds me of my own at 162K when I replaced it. The replacement chain was much tighter, but this was my experience; others with more experience should chime in. Were I faced with the picture you posted, I would replace the chain and gear set before reassembly.

[agthird]

you need to take the back plate off the oil pump it's the other ring gear you can't see that breaks....