Turbo spinning noise?

[Bnave95]

As of late when shutting down Eng. I can hear what I think is the Turbo spouling down. Just a couple of sec. What I do not like is it shoud not make any noise. When running, it's noise free. Other OPT. could be fan clutch.
Any hints that I can check?

[Robyn]

Howdy
Check the fan clutch hub assembly to make sure its not loose or otherwise faulty.
Pull the rubber boot off the air box and turbo to gain access to the turbine wheel. You should be able to move the compressor wheel very slightly back and forth and also slightly radially. If the wheel is sloppy and rubs the housing its toast. When the engine shuts down the oil pressure drops to zero and so does the oil feed to the turbo. If your turbo bearings are getting worn this could cause the compressor fins to rub the housing causing the noise.
Without hearing it its tough to say but do check things.
Again the turbo should spin freely by hand with no noise at all. Repair is not a real big issue. If you catch them in time you can install a new set of bushings and seals. Once the housing is chewed up though its $$$$$$$$$$$ time.
I had the turbo apart on my 94 when I rebuilt the engine and went through it completely.
Let us know what you find.
Robyn

[DmaxMaverick]

I hear a lot of "hey...what's that noise?" during summer. If you use A/C, the noise could also be the pressure/temps equallizing in the A/C system.

Later models have a fan cooled radio, which makes a whirring sound after key off.

[Bnave95]

Had my wife turn off truck and the turbo spinning is the noise. Can't hear it when running. I've notice this before. Sounds dry:eek:
Funny when one ownes a Vec. for many years, When normal noise change the ear dino kick's in. Part of the butt dino also:D

[DmaxMaverick]

Check the end and radial play of the spool. It isn't dry, or it would be toast by now, and surely wouldn't spin enough for you to hear it. The noise could be blade contact as it spools down when the load is off. Could also be an imbalance. Either case will spell a short life remaining, and the longer you wait to correct it, the more $$ it will take to get it back up to par. This is assuming it is in fact, a new noise.

[Bnave95]

Check the end and radial play of the spool. It isn't dry, or it would be toast by now, and surely wouldn't spin enough for you to hear it. The noise could be blade contact as it spools down when the load is off. Could also be an imbalance. Either case will spell a short life remaining, and the longer you wait to correct it, the more $$ it will take to get it back up to par. This is assuming it is in fact, a new noise.
Did check the turbo and spins freely.No radial play and end play. I could question myself about this being a new noise. The only thing I can say is the leading edge(first set) of the turbo blades are not smooth, rough,very small chips.More like pitting on the front.It looks like it's wearing. The 2nd row of blades look uniform on the leading edge. Water Injection could be wearing away the blades? Years of running a K&N filter before the afe.? Your really have to have a good ear to here this;)
To see if anything changes. I added a Qt. of Lucas.
The imbalance could be a issue. Would'nt mine a pic's of other's turbos.

[DmaxMaverick]

Have a look at it during shutdown. If you can see the compressor wheel now, repeat the conditions that create the noise, and watch the wheel. Short running in a relatively clean environment won't hurt anything. The noise may be nothing, that you just now began to notice.

WMI? It's possible. I've seen compressors after 100K with no appreciable erosion. More likely would be the quality of fluid you misted. Hard water deposits could have built up on the compressor, and are now chipping off. What does your mist jet look like? Any scale?

Air filtration? Doubt it. If you got enough (or large enough) dirt in it to "chip" the compressor, I think your engine would be having other issues.

[Bnave95]

Watched the turbo spin, flashlight in hand all seems normal,though I'm not sure what I'm looking for?
My son has a strob light:rolleyes:The WI fluid I use is windshield washer from a doller store @ $1.00 a gal mixed with denature Alcohol with inline filter. Misting nozzle http://www.mcmaster.com/
1/8" 9.49 GPH 15.00 You'll get the smallest, most atomized spray droplets with a cone spray pattern. When liquid comes out of the nozzle orifice, it strikes a brass pin which creates a fine, cone spray pattern fog. All nozzles are made of brass. Spray angle is 90

[JohnC]

Not to state the obvious, but d you have any new intake or exhaust leaks?

[Bnave95]

Not to state the obvious, but d you have any new intake or exhaust leaks?
No,the sound is from the turbo. After a quick Eng run up,shut down,I can see the turbo spin down and the pitch of the sound follows the turbo speed. Now if only I knew how to post a sound video.
I'm stumped,so I'll need to fine a shop that deals with turbos.

[ronniejoe]

The water injection is eroding the compressor blade leading edges. This is not a new or isolated phenomenon.