Odd noise from the, turbo?

[JDMills]

I have recently noticed a new noise in the truck, which has me uneasy. It seems that when I am pulling a hill, in 4 th or 5 th gear, there is an occasional change to or may be it is an additional squeal to the normal whistle of the turbo. it is intermittent, and will go away when i lift my foot off the throttle, only to come back when I resume.

It has kind of a harsh note to it, and the only thing I conclude is the turbo bearings are going. Yet the impeller spins freely... although I have nothing to compare it to. all opinions are welcome and appreciated.

Thanks

 

[JLEONARD]

Have you checked the axial (in and out) play of the turbo? When your calling for power the turbo shaft gets loaded against the thrust bearing.

I don't know what the specs for this unit is, but I wouldn't think it would be more than about . 010" or so. Try pulling it toward the intake housing... it should not be able to touch it. If it can, stop driving the truck and either replace the turbo or rebuild it.

I had the thrust bearing go on mine last year... . the intake turbine was hitting the housing... I was lucky that the engine didn't self destruct from all the aluminum dust it ingested.

But the turbo was so far gone I couldn't rebuild it.

Hope this helps. Good luck.

Jay

 

[sparks57]

Huh, so what is a good regular test procedure to make sure your turbo is in good working order?

 

[rowland]

I had the exact same thing happen on my '89, just a intermitent high pitch sound when under load. Turned out that one of the hose clamps on the rubber boot had failed. Under high boost it start to leak, resulting in a high pitch noise. Assuming your truck is still non-intercooled, check the connection between turbo and the crossover pipe. That might be the problem.



Good luck,



Isaac

 

[JDMills]

Thanks, I will do both just to be sure. I am hopeful that it is a hose clamp, but then it could be a good excuse to edge away from a stock truck. . if any one has other ideas, i will read them and investigate. I see it as a opportunity to learn more about this fantastic truck.

JD

 

[dpuckett]

What kind of squeal is it? Does it sound like a cross between a bird chirping, and a fan or alternator bearing going south? If so, I'd almost bet on the head gasket. Had it happen in my 91 (11/90 build). Didnt realize it could be that. I thought turbo, too, and replaced it with a used PDR HX35 I got from a fellow TDR member (good excuse to upgrade, plus the original had WAYYY too much endplay in it). No change. At first, I could make 25 psi, then it slowly over the course of 10K miles, got to where I couldnt make more than 8 psi without it squealing something fierce. I read on this page www.dieselinjection.net that in the bigger ones, it could be a head gasket, so I checked into it, and a few guys said it COuLD be, especially after ruling out all other possibilities. I replaced the HG, and sure enough, that fixed it.



The '90 Chrysler manual calls for . 001-. 003 inches end travel of the shaft.



Daniel

 

[Greenleaf]

Turb Spec's

I answered a post not too far back about how you measure wear on the turbo bearings. If you need it, PM me and I can send some specifications your way.



A high pitch wine can be a leak or,,,,,,,,,,,,,, normal operation,depending when you hear it. My bus drivers will tell me of a loud squeal when pushing down on the go peddle. It usually is nothing more than normal operation. A leak can be difficult to detect as it often sounds the same as normal whine. If you are familiar with the every day sounds produced by your engine/truck then detect something unfamiliar,investigate all possible avenues.



Scott

 

[phillips5]

Not only check all the hoses and clamps but also all the intake manifold bolts. When a bolt or two are loose man what a squeal

 

[Midnite]

Originally posted by CB_Parker

Huh, so what is a good regular test procedure to make sure your turbo is in good working order?

I just do a basic check on mine at every oil change.



Mike

 

[JDMills]

Hey this is great! The truck is not right out side, so I will have to wait until Saturday morning. But i am gonna check the hose clamps, then the intake manifold bolts, then a close inspection of the turbo. . although I have not got a dial indicator. kinda hoping that it is not a head gasket, but if so, I look forward to the challenge.

The noise goes from a whistle to a slightly deeper and kinda squeaky like. I have no experience with alternator bearings that go bad so my noise association abilities are limited. but it kinda sounds like metal on metal, yet how would I know? Actually I am looking forward to the investigation. Thanks for all your help.



JD

 

[dpuckett]

The only way to know is eliminate all other possibilities and then change the HG. My HG LOOKED ok- couldnt see any obvious place where it had blown- but when I got it all back together, it no longer made the noise.



Daniel

PS- it isnt too bad a job. Cleaning and prep take more time and effort than anything. The head weighs about 120#, and has some SHARP edges.