Timing chain?

[seann]

On my 93 5.7l Gmc I get a decent rattling when I cold start her or even when I'm driving I get a kinda whining sound but not as loud as the knocking sound when she's idling. This truck has 290,000 miles on her, any ideas?

 

[Molson02536]

On my 93 5.7l Gmc I get a decent rattling when I cold start her or even when I'm driving I get a kinda whining sound but not as loud as the knocking sound when she's idling. This truck has 290,000 miles on her, any ideas?

Check your serpentine belt tension idler arm and bearing. The other area to check is your alternator bearing. Remove your belt and idle the engine and see if the noise is gone. If it is then inspect the accessory bearings to your idler arm and alternator and replace as needed.

Start with those simple thing for now and then we ca from from there.

Molson02536