bradler

Posted this over in the 3rd gen but nobody seems to know. Thought i would check with you the knowledgeable 24 valver's.

The squeel coming from my mighty cummins is driving me crazy!! No mechanics, dealer or ortherwise, can tell me what it is. It does it consistently after she is warmed up, and is very loud at idle. Seems to get faster/quiter with increased rpm and then gets drowned out at higher rpms. And its not serp belt or related pully, seems to be coming from the block near manifold/rail on drivers side. Thought maybe pilot bearing but it doesn't change if in nuetral or in gear with clutch engaged or not.

So at idle, could you hear main/crank/rod bearings going bad, or any other internal bushings??

Also been noticing a slight squeel when under load on decel that goes away when clutch is disengaged, could they all be related, maybe camshaft bushings???

This is going to be fun to get the dealer to diagnose/warranty i can tell already....guess i will start by analyzing oil for signs of bearings going south...

Thanks for any ideas!

Dwitt0187

it will beat hard in the bottom end of the motor sounds like a little man in the oil pan beating on the inside of the block with a hammer.

danny

patdaly

I would think given the combustion pressures that you would not get it to live long enough if it were a bearing problem.

Perhaps a seizing wrist pin? On gassers it sounds more like a squeek than a squeal, never heard a diesel with one, so perhaps it might be more acute of a sound.

That's my best thought.

John Faughn

Rods & mains would make a knocking sound .
No camshaft bearing in the Cummins .
Squealing sound would be more like a roller/ball bearing , turbo , throwout bearing .
I like to use a stethoscope to help find noises , bearings , vacuum , exhaust .

dozer12216

If sounds like from front of engine, try this. Squirt a little oil between crankshaft damper and front cover. You are just trying to get the seal wet with oil. If the outside of seal is dry, can make a real squeal.

Busboy

Could you have an intake manifold leak? Possibly a lose bolt into the manifold?

bradler

Thanks Guys!
First thing I did was check all manifold bolts and then exhaust clamps, everything seems tight. Went over everything with stethoscope too and can't pin point it. Actually I thought it was coming from the rail relief valve leaking fuel and capped it, didn't do anything.

Guess its good news that there is no knocking, helps rule out internal bearings but i might do an oil analysis anyways. I know sounds can echo around under the hood, but it really doesn't sound like its coming from the front. Guess I will revisit the serp belt and all pullies and try some oil on the crankshaft damper.

bradler

Would noise from throwout or pilot bearings change if clutch was disengaged?

mslashbar

You could pull an oil sample and have it tested. If it's something internal in the engine, the type of metal which shows up in the analysis might help in determining the problem.

Busboy

With the clutch pedal pushed down both the pilot bearing and throwout bearing would be turning, with it up neither would be turning.

bradler

So if the squeal doesn't change when pushing clutch in or out could that mean input shaft bearings?

Also, was wondering if i could double check that its not belt related by shutting her down real quick while its squealing and removing the belt and then starting back up to see if it still does it? Water pump and fan wouldn't be working but would it hurt anything if only for a minute?

Thanks again, Ryan

nickg

Belt squeal can be eliminated by squirting water on it, it will stop the noise, as long as you keep squirting water on it. removing the belt wont hurt anything (might set an alt/charging code, no biggie ) but it is a pain to remove and re-instal the belt....trust me if its a belt water will tell you. if the water trick dont work remove the belt, to see if the noise stops. if it does then its a bearing somewhere, ie alt/waterpump, idler...
I've also seen the idler pulley wear on a taper forcing the belt over and causing a squeal, so pay close attention to the tensioner pulley, BTW the pulley can be replaced seperately from the tensioner at a fraction of the cost of a new tensioner IIRC it was under 20$

Busboy

With that statement I thought you HAD removed the belt and gave it a quick run.. That's what I would do to eliminate the pulleys. My guess is it's an idler or tensioner pulley. By taking off the belt you can then rotate everything by hand and you will probably find one that's rough.

bradler

Spraying the belt with water didn't stop it so this wkend i removed serp belt again, all pulleys seem smooth with no extra play. Also went for a ride with tranny shop tech and the guy doesn't think its tranny related bearings. When he listened to it at idle he also said it was coming from in between manifold and valve cover, thought it sounded like a vacuum leak. I'm running out of ideas....

mcknight77

Missing any cats?