CM871 smoke at idle...?

[cazlow]

Hey guys...

I have a cm871 that is in a 2010 Pete 388. It has 660k on it and was recently dpf/egr deleted. The truck runs great overall, but I have noticed what seems to be an excessive amount of white-ish smoke or steam at idle. It has been pretty cold lately (teens and 20’s), but seems more than usual. I am not using any coolant and maybe 1/2 gallon of oil between services. It doesn’t seem to linger, but is most noticeable when idling in a well lit area at night. No overly noticeable smells either... Not sure if I am being paranoid or if this is something I should have looked into further. Any thoughts?

[hhow55]

Who did the delete?

[cazlow]

A local company near me..

[JMBT]

Cummins has a known problem with the VGT turbos sucking a bit of oil (slobbering) at idle. Something about when the pressure falls too low on the compressor side it will suck some oil past the face seal. Hopefully whoever did the tune for you set a little positive intake pressure at idle. While your at a high idle, take the plug out on top of the intake manifold and see if you can feel a bit of air pushing out on your finger. It shouldn’t be much but you need a bit.

[Unilevers]

honestly it sounds like they used stock timing maps and stock OFC mapping. If you do this they run rich at idle and have very retarded timing which give them a white haze when idling as fuel builds up. When you start to drive after idling for awhile it will blow the excess fuel out and clean up. it should be fixed if that what it is.

[cazlow]

(12-07-2018 )Unilevers Wrote:  honestly it sounds like they used stock timing maps and stock OFC mapping. If you do this they run rich at idle and have very retarded timing which give them a white haze when idling as fuel builds up. When you start to drive after idling for awhile it will blow the excess fuel out and clean up. it should be fixed if that what it is.

Yep, it will... it’ll blow it out through the first few gears and then clear up.

[Rawze]

have the program pulled and looked at. 90%+ of delete programs out there are beyond horrible and will eventually tear the engine up.

Unilevers can look at it, or I can if you have someone pull out a copy of it and e-mail it to me.

[cazlow]

(12-08-2018 )Rawze Wrote:  have the program pulled and looked at. 90%+ of delete programs out there are beyond horrible and will eventually tear the engine up.

Unilevers can look at it, or I can if you have someone pull out a copy of it and e-mail it to me.

Ugh... So, I did confirm that it’s a “Cummins factory file”... basically, he said nothing special but a bump in hp. It was a 455 hp truck and is supposed to be around 525 now. For what it’s worth, it runs out awesome. The idle smoke is just odd/concerning. From what he told me, he wouldn’t suggest to change it but could and it may eliminate it... I think “changing it” just consists of turning it back down a bit. Also, I didn’t mention in my original post, but it has a slightly erratic spool under heavier part-throttle. Idk what to do but don’t want to cost myself more money than I already have wrapped up into this crap. lol...... I have considered talking to {name removed} but haven’t yet. SO.... what now? Suggestions?

[Lonestar10]

i would look at your valve cover plate and CPL number confirm that your truck is actualy a CPL that can do 525HP you might not have all the correct parts I.E. small/large turbo, injectors, cams and ect for a 525 Tune. if your truck isnt setup to run that horsepower it might be overfueling at idle due to mismatch between the cummins tune and what your engine can handle.