Water pump bearings banging?

CharlieMadison
Sat, 24 Sep 2016 01:09:18 +0000
Maintenance/Repairs

2000 GMC Sierra 2500 6.0L gas engine 150K miles. After returning home from a 150 mile drive, I notice a very heavy sound of marbles banging around near the front of the engine at idle. The noise is a much like heavy detonation where timing is badly off kilter. Used my stethoscope to determine this is loudest at the water pump housing. The belt runs smoothly with no sign of unusual resistance. The engine does not overheat, and there is no sign of a coolant leak.
Can a bad water pump shaft bearing make such a tremendous “cackling” noise?
What else could it be?
Thanks for any ideas.

9 posts - 7 participants