Engine/Transmission (1994 - 1998) Elusive Grinding/Worn Bearing Noise

[HLEschenko]

I have a noise coming from the the driver's side of the engine which sounds like a bearing going bad. I hear it when I first take off and everything is cold. It seems to quiet down to just a low growling/grinding noise when warmed up and motoring down the road at or below 45 MPH.



I can't hear it when I start the truck(1997) and can't find anything with a mechanics stethoscope either when parked.



When coasting the truck in neutral (auto), the noise seems to disappear. And it does disappear after 45 MPH. But that could because other cab noises get louder (wind).



I tending towards the transmission. Just turned over to 229K. Absolutely no trouble with the truck, power good, no transmission slippage. I did replace bearings in the differential about 10K ago.



Anybody have anything like this or maybe have an idea???

 

[KRStone]

go shake:



1) belt tensioner pulley

and

2) water pump



and see if either is loose



Ever replaced your alternator bearings?

 

[ktb]

could be your front wheel bearing, had one go out on my 03 not sure if the earlier trucks have the same style unit bearing or not, but the symptoms sound the same.

 

[wcjp]

Buy some cheap FRS radios. Have one keyed up and tape/attach to various locations until it gets louder. I would also lift the front end and check the unit bearing and the tensioner.

 

[ewcmr2]

Remove the serpentine belt and you can check the fan, water pump, tensioner and alternator by hand.

 

[HLEschenko]

Thanks for all the suggestions. I will give them a try.

 

[Extreme1]

U-joints? The front driveshaft has a CV joint in it that can selfdestruct if it gets dry.