*Big* Smokey Moment... +?Blowby +?BHG... WTF?

[ed]

Ok... basic story and specs are as follows, questions at the end

engine is now about 120km old. its got a decent base tune, and has had x1 oil change at 20mins. currently has 20-50w mineral oil, limiter is set at 6k and ive been in the process of just getting some km on the clock before the next tuning session hoping to bed things in a bit and get some compression up

oil change at 20mins was unremarkable, but dont know the exact volume that came out. didnt check the catch can but did note a fair bit of oil leak around it,so i just tweaked up the hose fttings.... note: catchcan is set up with an exhaust line plumbed into the headers at the collector

now, today i was driving a backroad, and simply putting the engine through the gears up anddown the revs on and of load...good run-in driving, nothing spastic. everything feels fine, engine is smooth, no miss, no funny noises.

i randomly look out the mirror to the back of the car and see a MASSIVE smoke cloud following me. i immediately kill the engine and pull over and get consumed in a cloud of white (with VERY slight tinge blue) smoke...

i figure ive fucked a ring or a piston etc, but the hour or 2 waiting for a towtruck got me thinking, the engine was running FINE, not a single suspicious noise or grumble... so i pluck up the balls and fire the engine on the side of the road and give it a bit of a rev. inititally nothing, then after a min or two things warmed up and some whisps of whitish blue smoke, but nothing like the cloud befoe i killed the engine. engine ran FINE.

checked the radiator, no bubbles, level is good, no oil. checked the oil, no milky crap, oil level i good in the sump.

had me confused to say the least

SO, i got home, and check things over more. catch can has about 2L !! of oil in it. so its entirely possible that the catch can dumped a load of oil into the exhaust and its been burning up and out the exhaust. but i digress... we emptied and disconnected the catch can.

we fire the car up again in the garage, things again SMOOTH... engine has nil obvious troubles. initially theres a bit of condensation type mist and light oil smoke in the exhaust, then it basically clears up and theres nothing. also, the blowby from all of the breather lines (at idle and no load reving to 5k) was basically normal. a few misty splatters, but nothing much.

so questions...

1 - what was the cuase of the massive rooster tail of smoke? oil overflow vs piston/ring? BHG?

2 - so it might have been that the catch can overflowed into the exhaust. but WHY would i have 1-2L of oil in my catch can so early?? maybe just from the first few mins before the rings bed in prior to the first oil change? something else more sus?

3 - why the white vapour type smoke? is it possible that there is a BHG lurking under all of this?

4 - what should i do next? let the suspected oil in the exhaust burn out and just drive it? keep an eye on the water levels? do a compression test? and again, whats with the blowby?

any thoughts or suggestions would bemost appreciated!

cheers
ed

[thechuckster]

positive crankcase ventilation not working correctly? was crankcase pressuring during run-in? is there any crankcase vacuum at idle or free revving?

[oldcorollas]

are you still running that exhaust PCV sucker thing? is it actualyl pressurising the crank case?

is it rich and washing the walls? (you'd guess not after the dyno run in and tune)

are the cam cover breathers just in shit positions?

what is the system with the catchcan and where does it all go?

i assume rings were properly end-gapped?

oil in exhaust will take some time to burn out, cos it takes time for the pipes to get up to temp.. feel like pulling them out and giving a wash and brush? (petrol would be enough .. make lawnmower fuel?)

[PlacentaJuan]

im not sure what the prob is but i do have a suggestion:

what type of car/engine package are you having problems with?

some details will prolly help, but at least you got more than the guy with the tranny problem in his commodore lol.

[ed]

the exhaust line on the breather has a one-way valve to stop back pressure from the exhaust pressuising the crankcase. im not sure what the actual crankcase pressure is like though. eyeball-o-meter free revving says negligable positive pressure. but dont know for sure

[ed]

what type of car/engine package are you having problems with?

catch can is in the top of the picture

also, cam cover breather pickups are totally baffled
crankcase is not baffled, maybe sunp was overfilled and managed to slosh right up to the breather pickup? dont know, but unlikely

[oldcorollas]

can run line off somewhere to a bodgy water manometer to check pressures?
or gauge if you are fancy...

1 way valve not 1-way'ing?

anyway, with that line disconnected it should rule it out...
disconnect long enough to burn out the oil in exhaust 8or clean first, then burn out), and see if oil keeps backing out into the catch can...

if it does, you have problme of both oil being too close to the breathers, as well as too much air...
2L is not oil vapour or droplets...... 2l is liquid oil getting pushed out (i would think)

edit: are the breather baffles in such a way as to not catch oil in behind them? and tolet oil drain away if it does get in there? i know some cars, under certain conditions, flood the baffle breathing area and spurt out liquid oil

[ed]

i agree,not just vapour, but a full pushout of oil. not sure when it happened tho. the pickup for the crankase is a LONG way from the oil level...

but would oil in the exhaust burn white smoke? is that enough to explain things? 2 diagnoses is unlikely for a single incident, so BHG isnt at the top of the list, but it did seem like water... i dunno

[oldcorollas]

sure, why wouldn't it
oil smoke is kinda white...
coolant smoke is kinda white.
buckets of white smoke = oil smoke.... doesn't have to be blue..

did it smell like oil smoke?

other thing is.. the after 1 or 2mins running thing could be coolant pressure or exhaust heating up..
but i would guess exhaust heating up.
if you take off rad cap, does smoke stop?

[ed]

did it smell like oil smoke?

too overwhelmed by smell of shit in my pants to notice. probably did smell like oil. thou in garage later, the small residual whisps of smoke looked like water vapour before disappearing all together

still smoked with cap on or off, and later when disappeared was tested with rad cap on and off.

all the time no bubbles in rad, no water in oil

[oldcorollas]

hmm.. any oil being pushed out of seals or gaskets?

just a thought.. if you are actually getting pressure in the exhaust, and that 1 way valve is closed.. then you need to have more crank case pressure than exahust pressure to open it..
but if you are not leaking oil out of seals or anything, that that is unlikely..
main peoblem (if it is oil) is htf it is getting past the baffles, and into the pipes...

edit: just elimiate sources first.
take off rad cap, take off exhaust breather and oil filler cap and get car up to temp, or until smoke comes out...
if not comes out, put rad cap on.
etc etc.

hmm.. porting couldn't have breached an intake port into water jacket?

oh, in garage later, until exhaust is hot all the way along, it will condense some water... which will come out as steam n shit

[Tweak]

catch can is in the top of the picture

also, cam cover breather pickups are totally baffled
crankcase is not baffled, maybe sunp was overfilled and managed to slosh right up to the breather pickup? dont know, but unlikely

OMG i think i just jizzed my pants. Hard to focus on the question with that image

*right click - Save image as*

[ed]

yup, with the sump trap doors, it could be possible that when a full sump sloshes against a closed trap door, it flows over the top and sloshes into the pickup zone of the crankcase breather (mounted on very top of the sump pan)

[gianttomato]

Drop the exhaust just after that vacuum point in the exhaust. Check to see if there is oil residue. If not, drop other side and check.

Big question is why you have 2 litres of oil in your catch can.

[oldcorollas]

there is no "return to sump" from the catchcan right?