Noise driving me nuts

[Dieselnerd]

I have a chirping noise that I'm unable to find. Noise is only present when the belt is on. Three different belts, three different noises. Gates green belt is the worst chirp. Gatorback causes a high whine that sounds like a turbo and stays there at higher RPMs, Mopar belt is quietest. chirping intermittent at idle.



Noise originally went away when the A/C was engaged so I changed the A/C compressor. Noise was still there. Changed the belt tensioner, changed the idler pulley, power steering pump is almost new and turns freely. Water pump spins free with no play or noise. Fan bearing has no play and spins freely with belt off.



I took it to the dealer and they spent several hours trying to diagnose the problem and said they couldn't find anything wrong, pulley alignment good, no bad bearings etc. They didn't charge me for the diagnosis (I'm a long time customer) and told me to run it for awhile to see if it gets worse. They didn't think anything catastrophic was about to happen.



The only thing left is the water pump. Anyone have a water pump make noise without any bearing play? The truck has 81,000 miles on it, I have a new pump I can try.



All ideas welcome.

 

[cerberusiam]

Yes, they will squawk even though they are tight. The problem is that usually means it is getting ready to starting leaking and causing problems. The fan support bearing is tricky. They will feel good but under tension make noise. Sometimes you have to wait until they feel rough when the belt off.

 

[DonFitzwater]

Is this a different noise than the one you experienced with the Fluid Damper balancer? Or am I confusing you with someone else?

 

[Dieselnerd]

Is this a different noise than the one you experienced with the Fluid Damper balancer? Or am I confusing you with someone else?

Same guy, totally different noise. I no longer have the Fluid Damper.

 

[Dieselnerd]

Yes, they will squawk even though they are tight. The problem is that usually means it is getting ready to starting leaking and causing problems. The fan support bearing is tricky. They will feel good but under tension make noise. Sometimes you have to wait until they feel rough when the belt off.

Thanks for the response, I'll try a new water pump tomorrow. I wanted to change the coolant anyway so I can change the pump at the same time.

 

[cerberusiam]

My OE pump started squawking so changed it. Ran about 20k and the new pump puked the seal. Had to out the squawker back on until I got to Cummins to get a good pump, not impressed with the Gates pumps. Stupid thing would not make noise all the time, just random depending on its fancy. It was just getting random more an more.

 

[Dieselnerd]

I changed the water pump today. The noise was gone when I started it up but came back after a short drive. It's more intermittent and not as loud. You can't hear it in the truck, you have to put your ear close to the radiator when it idles. Goes away as you speed up the engine.

I don't think it's about to leave me stranded on the road so I'll keep driving until it gets bad enough to find. The tech at the dealer said it was like chasing a ghost. He used a stethoscope on every rotating part before he finally gave up.

I still haven't replaced the crankshaft damper. The service manual does say that the damper can cause belt noise. My engine is stock and the damper is stock. The scribe marks are still aligned and the rubber looks good so that might be an expensive long shot I'm not ready to try yet.

I'll post again when or if I solve the problem.

 

[AH64ID]

If you look at changing the damper I would go with the 6. 7 damper.

 

[Mark31]

My '88 S15 GMC pulled that same trick on me. After changing dis an dat and being irked and frustrated for too long, we finally found it. The power steering pulley had a crack/split in it. Hope you find your gremlin. Mark

 

[HOBrian]

My 98 Dakota had a chirp with the belt off as well and it turned out to be the idler pulley.

 

[Dieselnerd]

If you look at changing the damper I would go with the 6. 7 damper.

I took your advice and got a 6. 7 damper. It's attached to a 2014 RAM truck and I know it will solve my problem. I wanted a new truck anyhow so I kill two birds with one stone.



See my post about "Taking the leap to 2014" in the 4th generation forum

 

[AH64ID]

Congrats on the new truck, they are purdy!!