Tralfaz

Hi everyone, I thought I'd put this question out to your collective experience before I start yanking my motor apart. I own a 91 Coupe (L98 motor). Starting the car, no noise. Regular driving, no noise. Stretching each gear out a little I get a wicked valve tap at 3000 rpm and up. But the car only has 22k on it! Could it be a clogged pushrod not bringing oil where it should go? Can a lifter give up with that few miles? If I pull the valve covers off, can I get to the lifters to replace them? Last question...can you "see" a bad lifter or is it all internal damage that creates the noise? Your input would be greatly appreciated. I'm all ears

The Beep

I'ld try some hope-in-a-can before ripping and tearing. Run it with a Seafoam-like product in the crankcase then oil change w/ Mobile 1.

Others will certainly disagree.

Pete K

The odds of a broken or damaged roller lifter is small. I would pull the valve covers and readjust the lifters. If you are lucky, a nut loosened up and one is slightly out of adjustment. If you suspect this, buy 16 new lock nuts. I like the gm nuts best. Inspect the obvious stuff while the covers are off. Bent pushrods, cracked rocker etc. If all is good, readjust and dump a small can of Marvel Mystery Oil in the crankcase. It is one of the few miracles in a can that can clean the internals of the lifter without damaging it.

Steel Breeze

Wonder if you are hearing a loud injector? Just a thought...

cv67

Sometimes the lifters can get varnished up and stick, especially if it sits a lot. The miracle in a can thing outside of pulling a valve cover to check for something obvious may be a place to start. Personally Id try a mechanics stethescope (if youre lazy use a long screwdriver) to try and determine exactly where the noise is coming from first.

RandyJ75

You could also have a cat converter going bad. The converter will only make noise when it gets hot, but will do it all the time once it does.

Tralfaz

thanks for the tips, I've already dumped a can of Marvel Mystery Oil in it with a fresh oil change. It hasn't helped much. I guess I'll pull the valve covers off next and look for the guilty party. Might not be a bad time to throw some 1.6 roller rockers in, right?

cv67

ttt