I must have watched 20 or more turbo surge videos with sound and it all sounds pretty much the same.
Sounds to me like a fluttering flute...like the instrument.

The sound I am hearing is corresponding in interval but much higher pitch. It's basically an intermitted turbo whistle.

It occurs when going uphill, 4th gear, when the truck is running out of power and ready to shift.
When in 4th driving say 65 going uphill it will slow to maybe 55-60 and shift as expected, sounds disappears.

My wast gate operates normally and I have no other issues...just the sound. Have power and no obvious leaks in the turbo whereabouts.

Belt is good as is the clutch and the high pitch sound is definitely turbo like.

Thoughts?




99.5 F350 7.3 160k Stock.

 

I believe you're hearing a high pitch churp or squeal probably only under load, probably towards the upper part of the climb?

I have went through 3 turbos, all gtp 38's, I have torn them down and noticed one of the two brass bushings is worn. This lets the shaft spin off center. The squeal is literally the intake wheel touching the wall of the intake. Remove the intake hose exposing the intake wheel. Shake side to side. There shouldn't be any play. There is a thrust bushing that pushes into the aluminum on the back side of the Intake on the turbo. All parts are relying on a film of oil to keep them separated. Check ebay for a rebuild kit. I paid $40 for a bushing kit. Cheap insurance, plus you can really inspect your current condition.
Hope this helps!

 

Yes! That it THE exact set of conditions. Last time I changed the filter i inspected turbo and wiggled it, don't recall any play but I shall check again.
Ugh. THIS looks like a mess.

How come you slaughtered 3 blowers?

 

Very good point !! But I would go with a rebuild kit with a 360* thrust bearing.

When checking the wheel any in & out movement is very bad and up and down it should move very little and not touch the housing.

I too would like to know why 3 turbos went bad.

 

First upgrade I did was a 5" straight pipe exhaust, I had bought the truck with 111k on it. Added gauges, a DP tuner and an over boost annihilator from Riff Raff. I Had REALLY bad turbo surge. Getting on the free way and get that last shift in and flutter from 15-20psi and loose power. I ordered a Borge Warner wicked wheel, this solved that problem. I could make up to 32 psi maxed out. But Do to EGT's I would have to back off the throttle towing my 32' fifth wheel up almost any grade. I was in a caravan heading from Vacaville CA to Pismo Beach CA. I made it 2 hrs to the first grade in Sunol, outside of San Jose. Climbed at a steady car passing 70, then the churp, churp, then steady squeal. I let off the skinny pedal and it went away. Thinking this was a tensioner, alternator bearing, I kept on with the trip. I Made it another hr, now on the flats in Gilroy that squeal again. I slowed to 65 and it went away. Not 5 min later and my wife and I thought a 747 came from the passenger side to the drivers side in a grazing emergency landing do to the loud noise and whizzing of a jet turbine. NOPE it was me, Wide eyed, I noticed in my passanger mirror 3 gal of oil pouring out and a white smoke screen 007 would be proud of bellowing out. Well I shut HWY 680 down do to the smoke for about a few min. I pulled over and started looing at things. Left the trailer, towed the truck home, and barrowed my brothers gasser OBS. So that was TURBO 1...
Findings: Snapped shaft, thrust bushing worn down 1/2 way, and a dime size hole in the oil galley to the intake.
The story repeats its self the following year heading to Pismo.. just less carnage. A pilot bushing had some play, wicked wheel severely rubbed the intake, started grinding.
3rd time, A week before 3rd year of going to Pismo. Same issue, one pilot bushing loose, thrust bearing wasted, and this time the exhaust wheel drove into the housing, trying to push into the intake side.
My theory is above average loads on wheels, higher rpms, and possibly loss of oil pressure. Its always the upper part of a hill the churp starts, always under a load. I want to add a gauge just to monitor the idea. Next I'll go 38R. Ill try to see if I have pics t post.

 

What milage are we talking? Seems unusual.

Maybe you should ask santa for a Turbo timer...

 

You took out three turbos in three years?

I'd take a serious look at your tuner. I'm very familiar with the grades you are pulling, and those are just little hills when compared to the steeper Teton Pass in WY, or the longer Tejon pass in southern CA.

If you drop a 38r in for the bb cartridge, you might burn that up too, which would cost you even more money. Something isn't set up right. Is the five minutes saved going faster up the hill worth the five hours spent pulling the turbo again? I'd pull the tuner first.

 

I hear ya lol, the first year was ignorance. Hitting aannd riding 1400 in the egt's. 1600 getting on the freeway.
The saying " you play you pay" well I'm tired of payin so I use the stock or 60 hp setting now. But I do suspect the tuner, its live tuned. I think my 80 econo tune burns the most gas, and has the most performance over my 100 or 140 tune.
I'm getting 460- 490 miles out of a 36 gal tank. This is in stock, 70 mph, 35" toyo mud terrains, 4 door, long bed, 6" lift, empty. Been commuting to South San Jose for 6 months... no churps, or squeals.

 

Ouch. Cow town to So San Ho? That's an expensive commute in CC 6" LB with 35s. Plus four hours a day in seat time just to ponder on how much it costs. Dang. There's gotta be a used Prius with your name on it for sale somewhere halfway between home and work, passing near and through the Prius capital of the world. Or get a plug in, and save 30 minutes a day in the diamond lane with your green tag.

Another thing I was wondering is what if you disconnected that boost annihilator thingy to stop overriding your wastegate release, if that is what it is doing. You might not need 32 psi of boost, when 20 psi will get the job done without having to get towed the rest of the way.

 

Well, my 7.3 brothers would hang me if I bought a prius lol.
I'm a Construction Superintendent and work pays the fuel, toll and gives me $400 a month for my ware and tare.
Just built a Safeway fuel station. Next one thankfully is in Napa. A truck stop I think. This week I was told take a paid week off for my extra time I put in. What better way to spend the time than this forum, and cleaning the garage for my next turbo lol.

 

So what explains the thrust bushing getting worn down in half? Or pilot bushing failing?
That leads to the squeal under load.
High EGTs burn the exhaust fins, still dont explain the rest.
Any ideas?

 

32 psi of boost explains at least a possibility to me. How does the same surface area of blade acting on the same shaft supported by the same journal bearings create that much more pressure, without exceeding the design limit of the mechanical parts that are factory limited to 66% of that pressure?

And fear not. At least three of your 7.3L brothers on this forum drive a Prius. Proudly, in fact. It just makes more $en$e. But when you need a truck for construction, you need a truck. Nuff said there.

 

Well M-S-G, I hope this helped, but sounds like we both should upgrade to 38R's!!
my best recommendation is the john woods trans. I put my chio in on sat, blew the front pump seal sun.
Dont do a K&N air filter. I run a 6637. The sand and dirt will sand blast your intake wheel with a K&N. Even well maintained and oiled.

 

Go with the 38R Justin! Prolly still pass smog most times, and then you're ready for injectors!

OP needs one too. Keeping the revs up can help. Click off the OD and keep the revs up where it doesn't bark back at ya.

 

Naaah. I don't even have a tuner and I'm only at 155k.
I'll get the $45 rebuilt kit thingy.

I only hear the sound when in the mountains and I don't even experience turbo surge at all.

EITHER WAY. Thanks so much for input. I shall rebuild and report if noise abates.

Thanks again!