Replacing turbos on C 15 Acert

I took my truck to Peterbilt for a high pitch squealing noise under the hood. The noise was on the right side of the engine, so I figured another hump hose had a hole rubbed in it. Turns out that both turbo impeller shafts have play in them and the impeller blades are actually rubbing the turbo housing. So I get to spend $4000 to replace the turbos.

Luckily, the turbos didn't come apart and damage even more. I was wondering of anyone else has had this problem, and if so, any problems after the replacement. Peterbilt says the turbos have been revised with better shaft bearings. But ####! I don't want this problem ever again.

 

Lucky there, good catch!!!

 

I have heard of some of the earlier high pressure turbos failing, but not with a shaft or bearing failure. It had something to do with the housing. You got extremely lucky that the compressor wheel didn't come apart. I have been trying to find someone with knowledge to give me a rough estimate of max shaft speed and PSI for the MXS ACERT turbos. So far I have pushed mine to 65 PSI and I am afraid that when I tune it to sled pull that number will get near 75-80 (or more) PSI.

 

im guessing u and this guy here have the same problem, is this what that squeling ur talking about sounds like? im also guessing urs is the twin turbo model too right?


http://www.youtube.com/watch?v=dQHPBGunBAU

 

had a piece of a sleeve i guess that is attatched the exhaust manifold gasket come loose awhile back. got into both turbos, also had the different pitch noise. drove me nuts cause i couldnt figure out what the problem was, looked at everything. finally said the hell with it and took it to a shop that previously replaced a turbo that blew. found out it tore the hell out of the turbine wheels on both turbos.

cat paid for everything. both turbos, gaskets, studs for manifold. they said they knew about the problems with the sleeves and are only paying for it as they go out.

 

Some turbo specialist should be able to give you a rough estime about max shaft speed if you give him the measurements of the turbine and compressor wheels. Theres some max peripheral speed that I don't remember now that you shouldn't go over. You should have 2 boost gauges, 1 for LP and 1 for HP side so that you know the pressure ratio of both of the turbos, max pressure is not so important.

 

Garrett sells a turbo speed sensor. Only downfall is you have to drill the compressor housing to install. I guess it comes with blueprints so you could have a machine shop do it.

 

Some modern engines have it from the factory, like S 60 Detroit, new Ivecos and Scanias with VGT Turbo.

 

I knew the VGT's did but you can add this to anything.

 

Mine would only squeal at about 35 psi and up and wasn't blowing smoke. I think as the boost would build, the shafts would flex or move, allowing the impellers to rub against the housing. I have already had the manifold sleeves and bolts replaced about 50,000 miles ago.