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Hi guys, been having some issues with my nb... it seems to have a mind of its own. Some days it will blow thick white/grey smoke out of the tailpipe upon start up only after the car has been sitting over night... this is presumably caused by the burning of oil due to leaking valve stem seals as i have been going through almost a whole bottle of it every week. The issue is that it will do this some days and run really sh*t, sometimes feels as though its only running on 2 cylinders and then when i open it up it feels as though a blockage has been removed and it starts firing properly, then other days its starts fine with no smoke and drives like a dream. the weather isnt a factor cause its been the same weather for the past 2 weeks and for the past week its been clouding up my street with so much smoke it looks like a volcano has erupted, yet the past two days its been starting perfectly with no smoke and runs smoothly all throughout the day.

note:
oil is constantly topped up while being careful not to overfill
black smoke also comes out of the tailpipe
black soot also comes out of the tailpipe only sometimes

if someone could please shed some light on this issue it would be greatly appreciated.

My original na6 engine did exactly this after i ran subaru upper cylinder cleaner through it.
Seemed like the carbon deposits were helping the valve stem seals out a bit haha.
I ended up rebuilding the engine and it obviously went away.

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What help do u expect? It is buggered, take it to a mechanic and get it rebuilt.

white/grey smoke on start up in condensation. normal for the cooler months.

blue/grey smoke on start it is worn valve stem seals. normal for old worn out engines need a rebuild.

i replaced a 265,000km old BP engine once that would blow oil smoke for 30 second continuously for 30 seconds every morning. that reminded me of james bond every time i drove up the street.

per above ^

White/grey = water/coolant
Blue/grey = oil
Brown/black = fuel

it's pretty normal for any car to blow white smoke during colder weather, often it's just a result of condensation in the exhauist etc after sitting all night.

I would be checking the oil, and the coolant to make sure neither are mixing (any oil in the coolant, or vice versa is a sign the head gasket may be stuffed)

I'd also take the spark plugs out and see what they look like. if your valve stem seals are worn i'd suspect the plugs to be a bit oily, and probably due for a change.

It's not necessarily rooted. It might just be a sticking PCV valve. When they stick shut pressure builds up inside the crankcase and it can force oil up through the rings and down through the valve seals and you blow smoke. When they unstick then everything seems good again.

Good aftermarket ones go for around $10 at Repco, etc. They just pull out/push in from the top of the motor. I'd give that a go first.