Hello all.
2002 5.3 (LM7). I've got a couple weird sounds. Newest is a chirping sound. Replaced both belts and all idler/tensioner pulleys. No change. Sound is almost definitely coming from the top end. I've never heard anything like this coming from inside a motor. I just had the rocker covers off also, chasing what sounds like either a flat lifter or an exhaust leak. No signs of flat lifters, head gasket leaks, or exh leaks. Any ideas *(mostly on the chirping sound)?

 

Did you run it with the belt off? Water pumps can make noise.

 

all i can hear is a p/s groan.
What he said...run with belt off. with the belt off...spin all the pulleys by hand.

New, cheap belts can chirp.

or belt still on with it running, spray brake cleaner on the belt and see if it goes away for 5 seconds. If no brake cleaner...put a dab of rtv on the ribs and run it and see if the noise is gone.

 

Talcum or baby powder on the belt is safer and cleaner than anything else. And it lasts a long time for noise. My Co. Express vans had squeakers on several I've had over the years and fleet management did not change belts for noise. Belt squeak makes me nuts, so I kept a squeeze ketchup bottle full of powder on hand and a squirt or two would stop the noise until the next rainstorm.