Thread: Grinding noise at idle

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Check for crankshaft end play.
It could explain the oil pressure problem.
If the thrust is gone because of the previous set up, it could be wiped out and deleting pressure and causing the throws/counterweights of the crankshaft to swing and hit the block simulating a "grinding" noise.

A bad rear main bearing will cause the oil pressure drop upon acceleration you describe. Could also be the source of the grinding noise at idle. Good luck!

Originally Posted by nitrowarrior

Check for crankshaft end play.
It could explain the oil pressure problem.
If the thrust is gone because of the previous set up, it could be wiped out and deleting pressure and causing the throws/counterweights of the crankshaft to swing and hit the block simulating a "grinding" noise.

excellent idea.....so far my paln of attack is to pull all the belts off and see if it goes away, it that doesn't work then i'm gonna unbolt the TC, try to isolate it in either motor or tranny and work from there. Thanks again!!

Maybe two separate problems? The grinding could be a cracked flex plate. The oil pressure drop and rise is a plain indicator of loose main bearings. It is conceivable that loose mains could cause vibrations that could crack the plate.

You didn't say what year truck. But if it has the one piece aluminum alternator,power steering,& A/C mount I would look there first,they where prone to cracking and would make a heck of a noise especially when you turned the A/C on.

it's an 82, non serpentine.....I'm thinking, flexplate/TC/trans front pump/crank-bearings.....the diagnosis starts tomorrow, thanks again for the help