vansickey

Twice now, my 8 has pumped large amounts of oil into the engine, causing loss of power and a huge cloud of smoke. The first time, i thought was a fluke with a sticky oil injector, now I am beginning to think it's a failsafe.
Both times were warm, 80f and 95f degrees. Both time were hard useage, once testing fueling curves and power, once autocrossing.
Scenario, WOT, all of the sudden, bogs, feather throttle, bogs some more, lots of blue smoke. Won't rev past ~4k breaks up. Doesn't completely foul plugs, stays running, smoking, breaking up, a few minutes of this, then back to normal, like nothing happened...Motor has normal power, no smoke, just an oily ring on the exhaust pipe.
Apexes? Oil injectors? Side seals? Program Failsafe? Any thoughts?

Huey52

iTrader: (2)

Clean your MAF, just to eliminate that variable. Could be anything you mentioned however.

But then, the more that software controls our vehicles the more chance for strange intermittant behavior!

RIWWP

iTrader: (2)

I'd lean towards oil overflow into the intake, or oil control ring failing.

Regarding both the oil injectors and the program failsafe, the maximum possible OMP rate (max pumping rate), won't generate smoke at all, much less a cloud of it. In fact, cranking the OMP to max all the time is common among AccessPORT users. So either way, I don't see how it is physically possible to suddenly dump alot of oil into the engine via the OMP and injectors. Simply not enough flow.

One source I can think of for that much oil that suddenly is from the oil control rings not keeping sealed.

The only other possibility that makes sense is a sudden overflow of oil into your intake. Do you run a catch can? or have the stock oil overflow tube (which runs to the intake).

Might be worth pulling apart your UIM. If you are getting oil overflow into your intake, the plastic sections should be pretty oily, and the intake valving should have carbon build up.

DocBeech

iTrader: (1)

if its blue its oil just an FYI

RIWWP

iTrader: (2)

Congratz on reading comprehension

vansickey

Thanks for the ideas!
The MAF is clean.
The OMP sounds unlikely to impossible.
Oil control rings... Do they Fail suddenly? And why would they seal up afterwards?
What about the side seals?
No, I haven't installed a catch can, maybe it's time... everything is stock up there. The fill tube overflow is damp with oil, and the line on top (jet air nozzle line) damp too (maybe from misfiring?) or oil drawn from the overflow tube but that seems unlikely, right?
If in fact that it was the overflow, a catch can would be a fix, but has me wondering, is this sort of thing normal? Since you mentioned, I'm guessing it's common, but does it mean somethings wrong?
With a piston motor I understand where the crankcase pressure comes from, but whats the deal here?
I'm gonna do some more looking around the motor, maybe something will stand out.

DocBeech

iTrader: (1)

I didn't read anything anyone else wrote, just threw it in there for a just in case.

RIWWP

iTrader: (2)

Actually, oil control ring failure isn't common. Oil overflow, in tiny amounts, is. Of the possible engine failure modes, apex seals are most common, followed by coolant seal in a far 2nd, then oil control rings far 3rd from that, and cracking the block extremely rare in 4th. Guesses there more than anything, just based on what I have seen over the past few years.

Just made that observation and deduction based on how oil could possibly get to the combustion chamber in that kind of volume.

However, coincidence or not, last night, low load, low rpm, low speed, I blew a large cloud of blue oil smoke for about a quarter mile down my street. Been having issues with my engine that we haven't been able to trace, mostly low end power loss and stumbling, running way too rich. This might be it. Seals up as the RPM picks up and the engine comes up to temp. Pulled apart my intake and no sign of recent oil, only faint residue.

I was just pointing out that it was in the OP's first few words that he knew it was oil smoke