Hi -

My 99, 7.3, 290K mile, 2WD dually yesterday decided to make some crazy noises. On quick review they sound like they are coming from the turbo, very much center rear of the motor and raise to shrill screech with throttle.

Was leaving the house yesterday, fully warmed up truck and had to get on it a bit to get out into traffic, live on a rural highway not a ton of traffic but need to get up to speed quickly.

As I put some solid foot in the truck, it started to make a shrill screech, pulled it over shut it down, checked belt, its fine.

Restarted the truck quiet at idle and as it is revved the screech starts, doesn't seem like a water pump, alt, fan clutch noise as it is coming from the rear of the motor and what seems very centered under the hood. I had to be somewhere so I jumped in the other truck and took off.

I did not set a CEL / SES light, drove the truck home but very slowly on the side of the road.

I have an AutoEnginuity and am going to pull codes this afternoon, will post to thread later. I will also post video of the truck running.

The only current known issue with the truck is that the glow plugs are bad and are due to be replaced prior to winter.

Questions :

Have any of you ever lost a turbo or a bearing in one and what were the symptoms ?

What boost pressures should I be seeing from a stock 7.3 turbo on the scanner ?

I am really trying to learn better diagnostic skills, anywhere else I should be starting my work to figure this out ?

Thanks

 

Before you run it much more, you should pull the intake tube off and inspect the compressor wheel. Then grab it and check for side and end play. See if it contacts the housing while you turn it and move it side to side and in and out.

 

Thanks, when I get home this afternoon ( different truck ) I will do so.

T

 

Did you hear the screech from the cab only, or from under the hood? The reason I ask is because the degass cap will screech as well. If this is the case, look in the bottle for anything other than coolant - including soot.

 

The screech is clearly under the hood towards the rear of the motor and what sounds very centered. I was right on top of the degas bottle up on the motor and no noise from the degas bottle area.

I could hear it with both the hood open and I was under the hood or from behind the wheel. not much difference either way.

T

 

mine sounded like an ambulance psassing by. My carnage was a broken shaft, not allowing ANYTHING to spin, within the turbo...yours, may be a different outcome...bushing bad, broken clip...etc. But, i'd do oil change if in fact, its the turbo thats bad. Can get rebuild kits from just about anywhere. But if damage to either compressor and/or exhaust wheel, then head on over to riffraff diesel.

 

Ok great, yeah mine kinda could sound like an ambulance passing ... Not exactly the news I wanted to hear but at least it is a step in the right direction.

When your turbo failed did it set codes or SES / CEL lights ?

T

 

no sir...just ambulance sound with the look of a freight train, on the freeway

 

Mine screached like that twice. Once was a boost leak at the spider and the other was a leak at the up pipe/baby's butt slip joint.

I'm not saying it's not your turbo....but if it's not there are other places to look.

 

Also check your tailpipe for oil. When mine went, it made the high pitched chattering noise and oil was dripping from exhaust.

Ryan

 

My turbo makes that really high pitched screech when I get the RPM's in the 2500 range, my turbo is going south as well but its hanging in there and it's been making that sound for a couple years, about 30k miles.

 

So here is a short video of what is going on,



I also hooked the truck up to my autoengunity and the manifold absolute pressure stays between 13.8 and 14.2 regardless.

Are there any other places I should be watching with the scanner ?

I am also getting an engine low back pressure code P0472

Any thoughts would be helpful

Thanks

T

 

Im trying to follow on my phone so maybe i missed it but have you pulled the intake to look at compressor wheel yet? Check out for play?

 

I have not pulled the intake yet, it was storming this afternoon and did not want to open up and expose the turbo to rain. My hope is to get it opened up tomorrow afternoon after work.

T

 

Afternoon Update...

I am pretty sure the turbo is toast... I pulled the intake off the front side of the turbo and the shaft did not feel bad but this is what I saw




So clearly the turbo is coming out of the truck, can anyone advise me on next steps ? I have never pulled a turbo apart, from what I read it does not look overly complex but I have been known to get in over my head.

Next steps anyone ?

The truck is going to have to sit for a bit as I have a long work trip coming up.

Thanks

T