Can anyone describe the sound of a spun bearing?

[Lonestar Honcho]

Hey ladies...gents. I'm needing some help with a problem that recently developed. My new rebuilt 22r I installed back in December is now making a noise. It has good oil pressure and drives down the road with no loss of power. When I throttle up it has a noise that sounds internal up above 1500 and also when in gear after releasing the throttle.
I'm not sure anyone can help, I'm just hoping for some positive comments cause I'm gonna be hating it if I gotta pull this sucka out again. Especially when its my daily driver.

Help a brother out tell me it will go away!

[superyota]

sounds like a spun or scored bearing.  I had a spun bearing but it would knock and make grinding sounds even at idle.  pull the pan and start checking your bearings.  If it's on your 82, you might have to put a jack under the frame and let the axle droop to get the clearance you need.  Hope i helped.

[Lonestar Honcho]

Thanks for the tip, Superyota!
I like your sig, I might have to take that into consideration too.

Anyone else have any past history?

[ROCKO]

before i replaced my motor i had a spun bearing. it would just make noise at higher rpm's kinda like a chatter noise also it would do it as i reved it up in neutral. replaced the bearing and it went away for till i change the motor. good luck

[Lonestar Honcho]

Thanks for the reply Rocko.
I've never heard of the sound before but that was a guess after it wouldn't go away.

I hope I can get it home...

[93tonkatoy]

When an engine spins a rod bearing, the engine will knock or rattle when running a steady speed on the road. the noise will lessen or disappear when accelerating or decelerating, and at idle. The sound will come from low in the engine.

A broken timing chain guide will cause a rattle when the engine is decelerating (tension on the driver side is reduced, allowing the chain to slap the cover), and be quiet when holding a steady speed or accelerating. The sound will be louder at the front of the engine.

Piston slap should be loudest when the engine is under load. This sound will come from the middle of the block, between the head and oil pan

The best advice I can suggest is to run the engine and try to listen for where in the engine the sound is coming from. Have someone rev the engine a little while you are listening. A mechanic's stethoscope will make this much easier.

From what you said about when it rattles, my first thought would be the timing chain guide. The easiest way to check this is to remove the valve cover and look for the tops of the guides through the head. They should be visible.

If you think that the engine has spun a bearing, you can swap them IN the truck. If you have a solid axle truck, you should be able to jack the truck up by the frame and get enough clearance to pull the pan. For IFS, you will need to drop the front differential, and unbolt the oil pickup tube before you can remove the pan (slide the pan to the rear to get the front pickup tube bolts and to the side for the bolt thru the brace, then let the pickup tube drop into the pan). Be sure to thouroughly clean the oil pan before re-installing, and check to see what is in the bottom of the pan (metal particles - and their color, chunks of timing chain guide...).

Also, if the bearings are spun, and it has been rattling for very long, it can deform the crank journal and also the rod journal (make them egg-shaped. New bearings will NOT fix this.  Use a micrometer to measure each journal twice at 90* and make sure they are 52.99 to 53.00 mm on the crank journals.

[Birfailed]

Holy ! after that tonkaytoy this guy won't even need a chiltons!