ISB 6.7 CM2150 problem

[Stovedude]

2011 Freightliner M2 106, 6.7 Cummins ISB CM2150, 90k miles. Bought at an auction in this condition. Idles fine, but can't rev past 900-1000rpm. It starts to sputter and lets out excessive gray exhaust smoke. Turbo spins but no boost. You can hold your hand over the compressor outlet and stop the flow. Did the d3man, along with the DPF/SCR/EGR, which helped a little, but it's still struggling. Pulled the turbo apart, and found the VGT gear to be sticky and misaligned. Realigned and cleaned everything up so the gear moves freely now, and put a new actuator on (calibrated with Insite 8.9). Idles better, but still the same problem. No active codes. Changed oil, filter, and both fuel filters. Did a cylinder cutout test, and each one caused it to run slightly more crappy. Starting to think someone put gas in the tank. Is there anything else I should check? TIA.

[Rawze]

(something to eliminate)...
same symptoms happen when the engine cannot breathe, especially the exhaust.

Disconnect the exhaust piping behind the turbo and if it runs and idles up significantly better.

next would be to also open up the exhaust manifold to let it breathe (before the turbo) and see if it runs and idles up significantly better, ensuring there is not excessive restriction from the turbo itself due to improper positioning. It can be done by removing the turbo mounting bolts and suspending the turbo so that there is a decent gap.

Also do a full EGR tune-up and replace the IMAP and other relevent sensors.. + ensure the egr valve is not stuck open.

[Stovedude]

Thanks Rawze. The DPF/SCR have been "disconnected" properly and everything is flowing freely. The EGR has also been properly taken care of with a kit. I did replace the IMAP, because it was reading 0.0 inHg. I can try the turbo thing. I have the air cleaner removed for testing. The turbo spins by hand just fine, and it's turning a few thousand RPM (don't remember how much exactly) at idle.

[Rawze]

If the thing has a de-mandate program in it, then the next thing to also do ASAP in fact, is to copy tyhe program out of the ecm and e-mail it to me for a proper review of what someone did in there.

MOST de-mandate files are extremely harmful to both the engine and its turbo, shortening their life significantly. It can odten be a cause of the turbo over-spooling and restricting exhaust flow (lowering fuel mileage and causing damage over time) too.

ref: http://rawze.com/forums/showthread.php?t...5#pid72945

[Stovedude]

I had Runnin Coal do it. It was way worse before the deman, although it could have been severely screwed up prior. Is it possible that some things could have been copied through to the new tune?

[DVT873]

How did the cold and hot side blades look on the turbo? If deposits build up the weight slows the speed and chokes it for air. Was a problem with midrange MaxxForce DT's. Have had them that couldn't get past 1300 RPM. Pull the turbo, block the oil feed and right to high idle, 2800 RPM. Probably not your issue but worth checking.

[Rawze]

(04-23-2024 )Stovedude Wrote:  I had Runnin Coal do it. It was way worse before the deman, although it could have been severely screwed up prior. Is it possible that some things could have been copied through to the new tune?

you mean 'running rough'?.
not really if he re-made it from scratch.. which he usually does.

[Stovedude]

Sorry, my bad. Yes. I did pull the turbo apart and clean all the blades. Everything was pretty sooty. The DPF was completely blocked. Everything is completely open now, turbo spins freely, and VGT gear moves freely. Maybe gas in the fuel tank?

[Notch]

I've had a customer's 6.7 in a RAM pickup that they suspected an employee had filled the diesel tank with gasoline. The truck ran poorly, would hardly rev, had some audible knocking/detonation noises when running, and had a ton of grey smoke from the exhaust. The big red flag for what was causing the issue was when the fuel filter cap on the engine was removed you were overwhelmed by the smell of gasoline. Surprisingly enough, a fresh tank of diesel and 2 new fuel filters and the truck ran fine and they drove it away.