Smoke at startup

Noticed my wife’s 2015 2.5 (67k miles) smoking at startup from tailpipe.

Appears to possibly be a bluish tint but I haven’t examined it closely. Leads me to believe oil burning.

 

It clears up quickly and doesn’t do it when restarted quickly.

Seems like it could be valve guides or seals. Anyone know if these engines are prone to this?

 

Any snake oil worth trying?

 

What’s involved in a possible repair? Pulling engine?

 

Still runs good. Getting 29 mpg average.

Sure it is not just moisture coming out of the pipe due to condensation.

 

Laughing at oneself and with others is good for the Soul![emoji2]

Pcv valve starting to act up is a possibility. That might cause some oil accumulating in the manifold.

 

 

Is the oil consumption normal?

Pcv valve starting to act up is a possibility. That might cause some oil accumulating in the manifold.

 

 

Is the oil consumption normal?

 

Oil consumption appears normal. I have about 3000 miles on this oil change and looks to be about 3/4 the way between the two holes. ( 3/4 full)

 

I’ll look into the pcv. I would really like that solution!

So it seems like this is an intermittent problem. I’m now thinking a bad pvc (intermittently)

May be the cause.

As Yoda_One already asked, are you sure it's oil smoke you're seeing and not just ordinary water vapor condensation? How long does it last?

As Yoda_One already asked, are you sure it's oil smoke you're seeing and not just ordinary water vapor condensation? How long does it last?

 

Yes. It doesn’t appear to be white. And it has occurred after trips

Of 20-30 miles so I’m sure it had sufficient heat to burn if condensation. I would say it lasts 5 seconds.

I would suspect oil seeping past the piston rings into the cylinders, where it pools and then burns on start.

 

The PCV valve thing would be an easy thing to check, but a faulty PCV wouldn't push oil into the cylinder when the engine isn't running.

 

I don't think our boxer motors, with horizontal valves, would be prone to valve guide leaks leading to this. On upright engines oil stays pooled in the heads and then leaks down; our engines are more likely to drain back to the crankcase.

 

Inspection by borescope after sitting overnight should be able to confirm that there is oil pooling in the cylinders. There-after dry vs. wet compression tests would indicate ring health, and leakdown test would indicate how much is passing the rings.

 

If you do you have stuck rings, something like a BG44K engine flush could help free them up.

 

EDIT: In the past Subaru boxers were prone to piston slap. Is there a light rattle that goes away once the engine warms up?

Edited May 12, 2019 by Norskie
Thought of more

Update: I changed the pcv valve a week ago. I haven’t noticed any smoke at startup.

 

The old valve didn’t rattle like new but it wasn’t plugged either. Maybe occasionally it would allow too much oil by.

 

Pcv valve was fairly easy to change.

 

Nut driver to take Intake hose off of throttle body and a 19mm socket and long extension and wobble is helpful but not necessary. New OEM valve was $20 from amazon.

If the old didn't rattle then it was ripe for replacement. Give it some time to see if the oil smoke stays away.