Kenworth Cummins 871 High Crankcase Pressure smoking

Good day readers,

Another issue with my truck that I purchased a month 1/2 ago, a couple days ago when I was driving home empty I noticed some severe white smoke behind me in the mirrors, once I got home I checked and noticed it was just pouring out of the crankcase breather vent.

Oil pressure, oil/coolant temp was good the whole time I've been driving it, always kept pyro temp below 900f, and boost 40psi max. Never noticed a change in performance or on my gauges since I've owned it.

The guy I bought it from had a 25k work order for a melted cylinder #6 back in May of this year, they replaced the piston, liner, new head, new turbo, new compressor and some other things (just before I purchased the truck, and only reason why I did purchased the truck).
Also it had a complete overhaul (inframe) done in 2018.
The truck sat until end of June and then I purchased it and only got to put 120 hours on it until now the engine is smoking. It is throwing a high crank pressure engine light.

I had my cousins husband over last night who is a mobile heavy duty mechanic and he had a look, it wouldn't let us cut out any cylinders with the computer for whatever reason to see which cylinder could be affected, apparently the engine wasn't in the state for it whatever that means.
So he ended up pulling the valve cover off and noticed a ton of smoke coming from cylinder #6 and a little smoke from cyl #1. What would cause this?

Trying to start a business here but had nothing but 1000s in bills already, and less than 14 days of hauling. Truck needed a turbo already before I even put it to work, even tho the turbo was new in May. Lasted 2 months... got new turbo on for 14k and now 2 weeks later blowing white smoke hard. Been a real downer this truck.
Guess the past owners sold me a lemon and knew about it, telling me the truck will be good to go for a long time.

Why would the engine be smoking after only 120 hours of running, after over 25k of work done 3 months ago.

Best to do a complete overhaul? Or purchase a new drop in cummins with warranty? Either way this might make me go belly up afterall, as I expected to have a solid running truck and being able to accumulate some funds for repairs to come overtime, and especially since it had over 70k in work done in the past 4 years I didn't expect an engine failure in the first month of running it.

Any help would be greatly appreciated. Thanks

A little more info on the engine make, model and year would be helpful.

It is a 871 Cummins Isx15, 2009.

Next question--has this engine had any deleted emission work done to it?

I was told yes it has, and it was taken 15hrs out of town to get custom tuned because the delete. Not sure if that is true, but did run good for 120hrs since I've bought it. Until a couple days ago, then noticed alot of oil burning smoke from crankcase vent, also some coolant loss it appears, but no coolant in oil, and no oil in coolant.

Well not knowing what was done when deleted causes some big questions. When I hear about custom
tuning that throws red flags with me. The fact it has high crankcase pressure leads me to think a bad
piston liner issue. But with that said I don't trust anyone who does custom or they say the motor is custom
tuned. Without knowing what was done it's a rather tough question to answer. Up there you might find a
dealer that will work on it, down here they don't want it on the lot.

Really you need to find a shop to check this out, other wise it's all guess work on this forum. Not trying
to run you off but too many ideas and opinions about a engine no one has laid hands on guessing at the
issues and what caused it is just that guessing.

Truck Shop.

StudWorth said:

It is a 871 Cummins Isx15, 2009.

Click to expand...

Guess it shows my age and experience because when someone says an engine is an 871 my first thought is 8V-71 Detroit!

Me too, Ken. He isn't saying they are claiming 871 hp out of an isx, he?

kshansen said:

Guess it shows my age and experience because when someone says an engine is an 871 my first thought is 8V-71 Detroit!

Click to expand...

I'm 25 and was thinking that is 871 the cpl or what. But then again I do have a soft spot for them oil leaking screaming under power piles unlike Truckshop

Not to take from the importance to the OP of this thread but so there's a puddle on the shop floor.

Back to reality-These deletes are a gamble. Kenworth in Pendleton Ore in the last year has had two
ISX powered trucks setting in their back lot with trashed engines. One from the states and one from
Alberta. Both cooked to a turn. Can't and won't touch either one. Both were supposedly custom tuned.
This info came from the parts salesperson who calls on the shop.

Back to reality-These deletes are a gamble. Kenworth in Pendleton Ore in the last year has had two
ISX powered trucks setting in their back lot with trashed engines. One from the states and one from
Alberta. Both cooked to a turn. Can't and won't touch either one. Both were supposedly custom tuned.
This info came from the parts salesperson who calls on the shop.