willysmjeeps.com

I finally got my m38 jeep running after 3 years and now this! I made a video of the engine running. Can anyone indentify what could be causing this horrible noise? Thanks.
Steve
http://youtu.be/RWolTo3qHoY

Maybe a bearing or bushing? Run it with the belt off and see if it goes away.

sounds like a bird made a nest in your jeep and is trying to get out..but cant

WAG = Wild A**d Guess

Loose pulley on something! Remove belt (as previously suggested).

A possible way to locate it would be a stethoscope with a tube instead of the diaphragm dingus.VERY directional, just be careful where you poke it!

When you increase RPM does the noise stay quiet? or does it catch up again and you hear it at high RPM? What is your oil pressure? Can you get a vacuum gauge connected?
Do you feel any knock on the block when you put your hand on the head, block, oil pan, bellhousing?
Look at your belts, are they running true? be sure your crankshaft pully is not bent and wobbling (common to bend them during removal).
Video/audio might not be giving us all the sound. Does it sound like a whistle? or a knock?
Start isolating: What happens when you push in the clutch (take the trans and transfer offline)? disconnect belts, try your fording valve (change of tone?), I have had a couple of new PCV valves with a knock. get a diaphragm dingus (napa usually has them) http://www.amazon.com/Lisle-52500-Mecha ... B0002SQYSM

Most important try to be sure there is no damage being done (knocks pings, raps).

Let us know how its coming.

I would try to isolate also with a big screw driver and plastic end to my ear and touching the metal end to different parts,and I might start with the bellhousing. Sounds like metal to metal to me, almost like the ring gear against the bellhousing. Jim

could it be an exhaust leak?

Ran it with belts off, no change. Exhaust leak? It could be. It seems loudest by the PCV valve and down the exhaust header pipe. Will check today. Thanks for all the replies!

I got nothin' more, but I sure do want to know what it is/was when you find it! Don't forget the stethoscope tricks, they usually work great for localization.