Dmax turbo failure

[mattb5150]

My neighbor has an 04/05 Dmax that is at the dealer right now. He has had low oil pressure for some time and finally got the dealer to test it and they determined it was a bad oil pump. Appearantly the dealer pulled the pan and found pieces of the turbo vanes in the pan, now the truck has a new turbo, oil cooler and system flushed and dealer will take on 4 hour test drive monday to check for drivability before giving the truck back to him. He said the dealer told him that this was a known problem of turbo failure, however I have searched and can't find anything on the Diesel Page about this.

He said the thing was smoking out the pipe alot before he took into the dealer as well. I don't see how vanes could make it into the pan? Is his turbo the same as my '02 that has 99k miles on it? His is under warranty mine is about to go out. I'd like to know if this could happen to mine real quick.

Matt

[DmaxMaverick]

The LB7 and LLY turbos are very different. The LB7 turbo (what you have) has proven to be very reliable. Failures have happened, but it's very rare. Much less than I expected early on.

I don't know how the turbo blade pieces could get into the crankcase, unless there's a piston with a hole in it, or someone put them there. I find it hard to believe. I'd be suspect of what the mechanic found, but pretty sure it wasn't from the turbo.

I'd insist on more than just a new turbo after a failed oil pump. He should have had the oil filter cut open to see just what went through the pump to cause it to fail. My guess is the order of events was....contaminated pump, failed pump, failed turbo. Not the other way around.

[Idle_Chatter]

There's an oil drain pipe straight back to the pan from the turbo bearing. Oil/smoke out the tailpipe is an indication of turbo bearing failure. I too find it hard to believe that even aluminum shavings from the turbo could get into the pan, but it could have been residue from the failed bearing and fit that the tech misreported.

[DmaxMaverick]

I, too, thought the same as you, turbo bearing pieces in the pan. I don't think if that happened, they would be identifiable as pieces of the turbo. His definition of the pieces was "turbo vanes", which seems to specific to be something else. If there were "turbo vanes" pieces in the pan, the turbo didn't send them there through normal channels. Some other demon is at work here. Those pieces are more likely pieces of a piston skirt, bearing, etc, or something along those lines. The compressor housing and crankcase don't have a common ground.

I'd be more suspect of the course of events than anything else. A failed turbo shouldn't take out an oil pump, but the other way around does happen, when it happens. There's more wrong with that engine than just a failed oil pump and turbo.

[Driveshaft]

I'LL SECOND WHAT DMAXMAVERICK SAID.

[mattb5150]

I agree it sounds fishy to me, I'd want a new motor if I could get it.

Matt

[Diagonal Brace]

Jut curious but do they recommend letting the turbo cool down before shutdown? Any other turbocharged engine says you should let engine idle for a few minutes before stopping. Does GM have any similar notions? Thanks.