I'm stumped....any thoughts?

[Beaver]

I have a cm2250.
I have done all the sensors (imap,delta-petc) but I'm still having turbo cough, low manifold pressure on acceleration and during jake braking and also my oil temp is sitting at 220 just driving on the flats.
When the motor is up to basic operating temp (oil temp at190) everything works great...well except I still have the turbo cough and that only happens when I'm stopped not when shifting gears.
Also when I stop the truck or 1st atart it up the turbo sits at about 5-7psi for about 5-8mins then calms back down.

I'm lost and frustrated. I had the oil cooler thermostat replaced, also my turbo actuator was bad so I did that. Not sure what I should check next

I have been going to the cummins dealer in Coburg, Or and they basically say..."no codes? Not able to diagnos"
Any thoughts would be a huge help!

Thanks in advance!

[smorgan87]

Mandated i assume? First thought that comes to mind is a bad vg ring in the turbo or a bad turbo actuator. I personally would stay the hell out the stealer shops and go to a good independent shop. Rawze has a good vidyo on inspecting a turbo. gotta have insite though.

[snailexpress]

Turbo boost at start is warming up mode to shorten idle time to warm engine.
220F oil temperature is normal for engine with DPF/DEF.
Turbo cough could be caused by million thighs. Bad DEf, sensors, worn turbo, DPF, EGR list is too long.
Good shop with dyno can do it.

[Beaver]

Yes still mandated. So 40°difference between oil and coolant temp is normal? Dang crazy. I wonder why my jakes and manifold pressure goes to crap as it heats up. Also, I don't think ita the turbo helping warm up the motor, it happens when I stop too.

[snailexpress]

(01-19-2018 )Beaver Wrote:  Yes still mandated. So 40°difference between oil and coolant temp is normal? Dang crazy. I wonder why my jakes and manifold pressure goes to crap as it heats up. Also, I don't think ita the turbo helping warm up the motor, it happens when I stop too.

You didn't mention how many miles on the engine. Oil pressure. Oil change intervals, was DPF cleaned or never. SCR system inspected. DEF filter replaced. NOx sensors replaced or checked at least. I'll bet it packed with soot every oil passage. Some of passages on my engine rockers were plugged completely.
ECM is in control of emission and if it need to run hotter to lower emission it will do it. In idle too.

[Mr Hagg]

Rawze can chime in on this one. He just did one the other day and found that the EGR cooler was clogged up not letting enough exhaust gas flow through it..

[Rawze]

Here is one major direct cause of all that "caughing" problems...
http://rawze.com/forums/showthread.php?t...8#pid22458

I would suggest an appointment with Mr. Hags shop.

[Beaver]

Its got 556k. Yes did all of the dpf cleaning and nox sensor checks. Replaced oulet nox and doser injector.
Oil pressure is just over 35psi at 1500rpm.
Rawze, is Mr Hag up here in the Northwest? Contact info? I just want to fix it and run right. I'm a carhauler so we already get terrible mpg and I can't afford to stay down in the 4.8mpg range forever. Plus, it would be nice to learn more about my motor.
Thanks again gentlemen!!

[Rawze]

(01-20-2018 )Beaver Wrote:  Its got 556k. Yes did all of the dpf cleaning and nox sensor checks. Replaced oulet nox and doser injector.
Oil pressure is just over 35psi at 1500rpm.
Rawze, is Mr Hag up here in the Northwest? Contact info? I just want to fix it and run right. I'm a carhauler so we already get terrible mpg and I can't afford to stay down in the 4.8mpg range forever. Plus, it would be nice to learn more about my motor.
Thanks again gentlemen!!

Basically the post I referenced above concluded the following...

- Replacing the EGR pressure sensor would be first.

After that ...

- Pulling the turbo off, then the EGR cooler off, and then all the EGR piping + the EGr valve. Cleaning out everything like new again + de-sooting the EGr cooler, egr valve, and all other components. Then re-installing everything.

It may be possible to clean out the EGR cooler (preventing the removal of the turbo) while it is still on the truck but I think it would not be easy. The other components would still have to be pulled and cleaned though. Any chink(s) of carbon that got missed in the EGR cooler though might later go through the turbocharger causing its destruction, so it would be a risky move to do it that way.

-- I.E.> -- The whole "turbo cough" problem they have is a congestive failure of excess soot deposits that can only be solved by pulling everything apart and cleaning it out properly.

Doing this yourself is a PITA but only costs you the down-time to get it done. Paying someone else to do this would likely cost you almost as much as getting as decent de-mandate and being done with the soot-monster for good.