Engine/Transmission (1998.5 - 2002) Turbocharger breakup

[lfwood]

I think the turbo in my 98. 5 has bit the dust today.



After slowing for a left turn pickup and trailer, I accelerated briskly as traffic was approaching from the rear. Immediately, there was the sound of metal parts striking somewhere. I initially thought it was the trash cans in the open trailer that had just turned in front of me. What I almost immediately noticed afterward, however, was a definate lack of power. As there were no other noises afterward, I continued on the 30+ miles home. Hills that were easily done in 5th gear before, however, had a speed drop of 10 MPH by the time the crest of the hill was reached. I do not have a boost guage so cannot confirm the boost pressure.



I have pulled the air intake tube off the turbo. There is no apparent strike of the small fan against the venturi. As well, from what can be seen, the main blower vanes appear intact. There does not appear any dust or debris. The engine runs smootly without any unusual noise, and revs smoothly as well. While the intake tube was off the turbo, I briefly started the engine. The fan did spin up. When the engine was shut off, however, there was a harmonic at one point in the spin down that sounded peculiar. There is a minute amount of side to side lateral play in the shaft, but I do not know if that is normal or not.



I have the feeling a vane or vanes has fractured off on the exhaust side, which might account for the sound going front to rear. It is too hot to take the Pacbrake loose at this point (the Pacbrake was still operating when I turned it on) and try to look at the exhaust fan, but that comes soon.



Am I on the right track? I could not find history of exhaust fans fracturing, but I can imagine this is the sound I heard, as pieces were ejected down the tailpipe.



How safe do you think it would be to continue driving this truck to get it to a turbo shop, 60 miles away? My concern might be accelerated bearing wear due to imbalance and leading to the blower vane contact with the housing.



Any comments or insight are appreciated!



Thanks,

- Larry

 

[sg5054]

I wouldn't drive it if you found anything wrong with the exhaust side. It will likely continue to self-destruct if you do and the last thing you want is the intake side coming unglued... .

Try a flashlight and mirror, look it over real close.

 

[lfwood]

Well, taking off the Pacbrake was a lot of work for nothing! So much for jumping to conclusions! The problem was not on this side of the truck!

Last year I had to replace the VP44 pump. When reassembling everything the mechanic had apparently not tightened down the bottom clamp on the top connecting boot between the intercooler pipe and the manifold air horn. Just at the time I was tromping the accelerator, the clamping ring decided to slide down the pipe (which is metal), hitting everything in the way and making one terrible noise before lodging next to the clamping ring on the intercooler elbow. Of course, now the boost was blowing out the loose boot which was causing the loss of power.

Incidentally, the idea came to look here after I found the turbo in good condition and I went back looking through the archives for other ideas. Someone had reported a problem keeping the boots attached to the intercooler. So I went back and looked at that side. And there it was, a missing clamp. I had looked directly at this area once before but had not seen the clamp missing, probably because it is partially hidden by the Pacbrake hoses.

Needless to say, the owner is happy it was NOT the turbo! All the power is back again and you can even hear the spin up under load!

I am a bit surprised this clamp was loose enough to come off the boot. There had been no noticeable loss of power before this happened.

 

[MHagen]

I had the same thing happen to me 2 days ago. I thought for sure it was the turbo too. I had 33psi and 1250 on the EGTs for about 10 minutes while flying up I-76 by the Eisenhower tunnel (about 11,600 feet) pulling a trailer. I heard a metal sound and lost almost all my boost pressure. My tail pipe turned so black I had to pull over for other traffic's safety. It was a simple fix but for a second my heart hit the floor.



Mike

 

[obert]

Yeah, I went thru quite an episode with that. The hoses expand alot when pressureized, they work themselves free eventually. I found that evrything has to be lined up well, if the hose is under tension (either twist or streatch) it wont hold long even if the clamp is tight. I even broke one clamp!



Sometimes a hose will partially slip out with little or no notice to the driver, other than a loss of power. Other times, ... . well, pullin a grade with the camper one day one let go big time. I thought I blew a tire for that first split second and my wife near pee'd her pants.