getting a high pitch whistle noise only at idle. truck will make this noise on a hot restart, only at idle. No noise at cruise or under throttle.

I suspect the turbo is making the noise.....VGT?

here is a short video;

http://www.85merk.com/members/eric_s/IMG_0119.MOV

 

any ideas?

is the link to the video working?

 

Video not working for me on iPhone.

 

I can see the vid, but can not hear the whistle.....

Check the BACK side of the boots.

 

Got it now (at home on iPad). Hard to tell if it's whistling or ringing but definately a sound that shouldn't be there. If it's boosting well under load I'd pass on the cold side leak to start with(also it's making little to no boost at idle). Could be exhaust leak but it would be tiny and just the right shape to whistle.
I think I would pull the belt and crank it for a minute to eliminate a bunch of stuff at once. Alternator looks new could be a bearing in it-not uncommon. Maybe pull the air filter and tubing to look in the cold side of the turbo for the turbine wheel to be not touching the housing, free spinning, and end play on the shaft.

 

Yes, "high pitch ringing" describes the noise more accurately.

turbo seems to be boosting properly, at least there is no noticeable difference between now and the past 2 yrs I have had the truck.

I thought it was a an alternator noise too, installed a reman alternator and it made no difference. I had the belt off 2 weeks ago and everything on the front seems to be turning normally by hand, but I didn't start it with out the belt off.

 

anybody else able to listen to the video or have any Ideas?

I don't have a problem replacing or rebuilding the turbo, but I am not sure that's the source of the noise.

 

Take a long handled screwdriver, touch the alternator and hold it up to your ear, use a stethoscope, or something similar to determine the source.
Doesn't sound like the turbo to me.

 

I condensed the video so it should be easier to down load, if you were not able to before.

also, you need quicktime or windows media player installed on your computer for it to play correctly.

anybody else have any ideas? or experience with such a noise.

Listen for the high pitched ringing or whistle noise in the video.

 

I have a similar noise/whistle/chirp on my '06 with 99,000 miles now. But, mine only does it when decelerating or coasting. It won't do it at idle or acceleration. Since it only does it when I'm coasting, I can't open the hood and shoot video or put a stethoscope to anything. Mine almost sounds like a fluttery chirp. I'm really bad at describing noises, but that's the best I can come up with. At first I thought it might be a bearing on a pulley but I would think it would still do it at idle.

 

I would use a long piece of heater hose. Put it up to your ear and use the other end to probe around all of the boots, cac tube, turbo, alt, pulleys and etc to see if you can pinpoint it. I've used this method for years and it's never let me down.

Oh and I definitely hear the ringing/high pitched whistle. A piece of hose should really amplify that noise well.

 

Hmmm...it's an annoying ringing...or whatever you call it. I'd take a good listen to the water pump. Use the stethoscope or screwdriver method. Does it make that noise at all when cold?

 

An exhaust leak will sound like this, it is most likely the passenger side up-pipe with a crack in the flex joint, but it could also be the y-pipe flex joint, or the clamp where the up-pipes feed into the turbo.

Look for any signs of black soot around the joints or on the firewall.