When I bought my 97 PSD boy did the turbo whistle After 200,000 more miles kind of slacked off on the whistle if you know what I mean. After many miles and just living on my truck is whistling very weird not the turbo kind of whistle just at high rpm's between gears (with radio and windows down) It has to be coming from the turbo because if I stomp on gas pedal it will kind of fade out?? kind of wierd-I heard of someone speaking of some sort of boot or something on turbo that produces the (whistle)- could someone enlighten me on this so I know where to look for this or fix it?? With motor up and air filter off I checked for play in blades and/or wear and appeared fine. Thinking about checking the boost to see what it tells me but with any PS the word "turbo" seems to turn into $$$$$ signs. Truck is running great just this wierd sound

 

All turbos whistle. Run a big straight pipe exhaust and your truck will sound like a big rig.(cool IMO) I doubt the sound you are hearing is the turbo because you said it fades out when you stomp on it. Turbos spool up and get louder when you stomp on it.

 

Thanks for posting this!! My 97 PSD is doing the same thing. I have 80k miles on her and this noise just started. My noise seems to be apparent between 35 and 45 mph and goes away if I step on it. The noise also goes away if I put the truck in neutral while driving. I also don't think it sounds like a turbo thing. I would describe the noise as sounding like when you blow across the top of a bottle only at a much higher pitch. In fact, the noise is so faint (especially over the sound of the diesel) I doubt anyone else would notice it but me. Any thoughts on what is causing this would be appreciated.

Jeff

 

that is exactly what I said that is the sound to a tune--Anybody got a clue???

 

I thought it was just my ears that were hearing that noise, you described it perfectly. On mine it seems to be more apparent when I just get off the highway and stop at a stop light and then when I accelerate I can hear it very loud between shifts. It has bothered me for a long time but never knew how to describe it. I hope someone knows what this is.

Thank for posting it

Nate

 

Has anyone gotten any further on figuring out what this noise is??? Mine seems to be getting worse. When I got under the truck with it running I thought I heard it faintly when I put my ear next to the catylitic (SP?) converter. It has me concerned that it is the beginning of the turbo bearing letting go. My only other thought is transmission. Either way I am a little spooked to take this vehicle on any long trips...which is its primary duty after grocery getter. Any input would be appreciated!!!

Jeff

 

Check all intake connections, make sure they are tight.

 

maybe it's an exhaust leak... sounds like a good excuse for an aftermarket turbo-back exhaust

 

Maybe alternator? compressor? serpentine? just a thought.

 

I will give those suggestions a look see today hopefully. The other day I came home to just run in the house to get something. When I came out I approached the idleing truck from the rear and noticed the noise which to me would suggest exhaust or something coming through the exhaust like the turbo. I do not notice any increase in noise when I open the hood. Of course that could be because of all that glorious noise the engine is supposed to be making!!! I'll post if I find anything obviously wrong.

Jeff

 

When the 02 X is started about 45 seconds - 90 seconds as it is sitting there it sounds as if a valve is closed in the exhaust (perhaps for warming?). The idle on the motor increases and you hear something that sounds like a vacuum cleaner if you get close to the exhaust pipe. I have stock exhaust right now, ordered the banks monster exhaust + power elbow. I hear this noise when it is started, and sitting. If you go to put the truck in drive (step on the brake) or tap the gas it will stop the higher idle.

 

Okay, I took a look at it today. I got out the old stethiscope thing and started hunting. It appears that the idler pulley next to the alternator is the culpret. I'm not totally sure but I get a bit of an intermittant howl sound when I scope that one that I don't get on the others. Also, I am able to rock that pulley back and forth slightly and you can even see it wobble ever so slightly when the truck is running. The others don't seem to have that slop in them. I guess I'll order one and give it a try.

Question, how do you get the belt off.....do you put a torque bit on the center of the spring loaded tensioner pulley arm or on the nut on the pulley itself to release tension from the belt????

Also, what is a good source for a part like that or is it a dealer item only???

I will be thrilled if it ends up being something so trivial!!!

The turbo itself sounded fine when I scoped it!!!

Jeff

 

take tension off the belt and it comes right off. I forget if you need a socket or just the breaker bar. Do a web search for rock auto parts they have the pully for around 26 bucks

 

Well I replaced the idler pulley and that wasn't the problem. It was most definitely in the early stages of going bad though. When I spun it the bearing was making some nasty sounds. While I was at it I replaced the belt, fuel filter and air filter. The sound is still there and is quite easily heard if you lay below the catylitic converter though I can detect no exhaust leaks. I guess I'll just have to drive it and hope that it's nothing serious. I'm just not looking forward to that next long trip!!!

Jeff

 

Jeff396/DCClark

What you're hearing is the exhaust Backpressure Valve (EBPV) in operation. It's a butterfly valve that closes in the exhaust stream immediately downstream of the turbo. It's supposed to help the truck warm up faster. and it will cease when you apply the break or accellerator