It's not a belt
06-11-2017, (Subject: It's not a belt ) 
Post: #1
It's not a belt
2009 Pete 388
ISX 79329607 (esn)
I'll keep it as short as possible. I started working here April 3. Fired her up while I put my things in the truck and right away a loud screeching sound I took for a belt. I'll deal with that later I told myself, it was now the 5th and a load of 9 cars was waiting. The noise faded upon warming up and for the first few weeks was barely noticeable.
Then came the "nosedives". A pair of back to back episodes where upon my getting into the throttle, all manifold pressure dropped with what could be felt in the seat going from a slightly positive g force during acceleration to instantly a negative g force (throwing you forward against the windshield if exaggerated) combined with the empty, throaty sound like an engine just puked. It may seem silly but I can't describe it any other way, but all this I felt under my right foot.
Weeks go by and the screeching slowly becomes louder. Week #5 and I get the first​ call for a Regen. I park and hit the switch while I air up a tire. Son, you talk about loud. Screeching was louder than it ever been and the engine revving up, down, up, down. 30 minutes she was done and it took a lot of the screech out for the next week. Back to hardly noticeable. But shes back to loud as ever and I tell the owner since I'm heading back towards the shop in Florida he should take a look at the turbo. I'm concerned the bearing is fixing to lock up and I'm hearing metal on metal screeching. I'm trying to avoid a several thousand dollar increase in cost to repair out on the road over what could be repaired in house.
3 days after I get in I'm back to a truck left untouched. Oh that's nothing major maybe a belt is what Mr "been in the truckin' binness 30 years" expert assures me.
I'm no expert. But I'm pretty damn good with a wrench in my hands going back 25 years to a teenager swapping out engines and tranny's laying on my back in gravel. I have a vast knowledge of all things mechanical in particular the workings of the internal combustion engine, 4 stroke, whether it's spark or pressure the source of ignition.
I've done some research lately online with much of it coming from this guy named Rawze.
Sidetrack- its a rare delight to watch video and read information from someone that all the while allows me to keep up by explaining what he's doing, how he's going to do it, and why hes doing it. From video#1 on EGR tune up where he says he's never done a video before I must say a better job couldn't be done by anyone. Thank you sir.
I'm leaning towards VG actuator or related. The thing is nosediving everytime I downshift. Big truck behind me pulling a hill beware. That car hauler in front of you is gonna drop 15 real quick and you oughtta left lane it even quicker. I'm letting her do her thing and just keeping pedal down until she coughs her way out of it. 4-5 seconds and by that time R's are lost and another gear needs to be found.
Hey, if it comes to a meltdown of all 6 pistons it'll be on Mr Truckin' biness.
I have video of a gear drop episode[/size]
 Thanks given by: fargonaz
06-12-2017, (Subject: It's not a belt ) 
Post: #2
RE: It's not a belt
Definitely sounds like the turbo is failing. Pull the intake boot off the front and see if you can see where the vanes have hit the housing and reach in there and feel how much play there is. You could also pull the outlet elbow off and see how much oil is going into the charge air cooler.
 Thanks given by: fargonaz , hhow55
06-12-2017, (Subject: It's not a belt ) 
Post: #3
RE: It's not a belt
I'll do that. I been using the excuse that it's too intermittent to put it off and steering me towards actuator. Thanks
06-12-2017, (Subject: It's not a belt ) 
Post: #4
RE: It's not a belt
Every time I have heard that metal-to-metal screeching -- most of the time the truck driver swears it is the turbocharger going bad but rarely it ever is. Shop gets you for a new turbo when in most cases all it was is the mounting gasket instead.

The most common cause of that horrible screech sound is actually the mounting gasket for the turbo itself or a manifold gasket blown out and/or failing and screeching very badly. Sounds horrible like someone letting the air out of a metal baloon and is very loud. Some describe it as A metal to metal high pitched white-noise type of screech. Sometimes you also loose a bit of power when it screeches because it looses back-pressure to drive the turbo when it does it too.

There can also be a problem with the turbo, don't rule it out, but the screeching itself is not likely to be the turbine. When the turbine is touching something it does not make a screeching sound but a very distinct high pitch whine instead described the same as a ringing in your ear, and has no white-noise screeching mixed in.

Do a turbo inspection and look for damaged vanes and metal shavings. There is supposed to be about 0.045" of side-play in the turbine. It is not supposed to be completely rigid. If it is not the turbo then it is more likely to be the mounting gasket where the turbo meets the manifold.

Had guys come over here after 2 different shops said his turbo was toast. ... He got it screeching really badly while here and I walked over to the turbo and touched the side of the mounting gasket (on one of the tabs of the gasket sticking out) with a long screwdriver and the sound stopped immediately. -- New gasket later and it ran like a champ again. - Not saying this is your problem but that is where I would definitely look first if no metal shavings or visible damage to the turbo were found.


Even if it is only the mounting gasket, it is bad for the turbo and the truck. It will cause fual mileage loss and a lot of other boost related issues including problems with the regen process and excess soot problems in the engine. It will also cause hot exhaust gasses to drill holes and/or etch the mounting surfaces where it is leaking and cause sealing issues with the new gasket. This in turn can make for repeated failures and expensive component replacement to get it stopped/sealed properly.

I.E> -- IT IS A BIG DEAL AND NEEDS TO BE FIXED!!! Unlike what some complete idiot of a mechanic would tell you.

turbo screech, turbo squeal, turbo rub, metal baloon, metal to metal sound

User's Signature: ->: What I post is just my own thoughts and Opinions! --- I AM Full Of S__T!.
 Thanks given by: fargonaz , Nilao , trucklogger2 , gatow900 , hhow55 , Shakeymike359 , Waterloo , Mrkentee , tlzimmerman
06-12-2017, (Subject: It's not a belt ) 
Post: #5
RE: It's not a belt
(06-12-2017 )Rawze Wrote:  Every time I have heard that metal-to-metal screeching

Another great writeup from Mr. Rawze!!!!

User's Signature: It's hard to win an argument with a smart person, but it's damn near impossible to win an argument with a stupid person
06-13-2017, (Subject: It's not a belt ) 
Post: #6
RE: It's not a belt
Thank you sir. I believe I'll get out there and do some inspecting. I'll let you know what I find out.

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