Random/intermittent blue smoke on start

[Darth Veynar]

2020 Outback with 45K miles. I have experienced random intermittent blue smoke on starts for over a year. Sometimes once month, other times 2-3 months in between. This last two months I've had 4 over a 4 week period. Always on a cold start. Not just a little puff, quite a thick cloud for 5 -10 seconds. Dealer said 'keep track' of them. I haven't seen any loss of oil (or coolant) or change in performance. Car is under 80K warranty. Anyone else seen this? Next month is scheduled check.

 

[txkreddog]

I'm not a mechanic, but since no one else responded yet, here's my 2 cents. Coolant leaking into the exhaust system is a white, steamy color, excess fuel is black smoke, and oil creates blue smoke. It sounds like oil is seeping into the combustion chamber somehow. Good luck, keep a close eye on engine oil level.

 

[Rattlenbang]

If it's just start up you're getting oil accumulating in your cylinders as it sits. In a typical upright inline that's valve seals but less likely with a boxer engine. But this is one drawback to the design and why these engines burn more oil than upright engines, lying sideways they don't drain oil as well as a vertical engine will.
There's a number of possible reasons why a lot more oil is accumulating now than in the past, and none of them good. Since it's under warranty it's imperative you get it dealt with before warranty runs out.

 

[Mark Monte]

Check your PCV valve! And how old are the sparkplugs? Here is what I got from possible causes:
Basic troubleshooting: If your Subaru is showing signs of burning oil and you suspect it may be due to damaged valve stem seals, there are a few things you can try before bringing it to a technician:

Replace the spark plugs: Worn or fouled spark plugs can contribute to oil leaking into the combustion chamber. Replacing them may help improve engine performance and reduce oil consumption.

Change the PCV valve: The Positive Crankcase Ventilation (PCV) valve plays an important role in regulating crankcase pressure and preventing excess oil from being drawn into the engine. A faulty PCV valve could contribute to burning oil.
Use a thicker viscosity oil: In some cases, using a thicker viscosity oil can help reduce the amount of oil that is burning in the combustion chamber. Consult your owner’s manual or a trusted mechanic for recommendations on the best type of oil to use for your Subaru.
Regularly check and top off oil levels: Keeping an eye on your Subaru’s oil levels

 

[Labradog13]

2020 Outback with 45K miles. I have experienced random intermittent blue smoke on starts for over a year. Sometimes once month, other times 2-3 months in between. This last two months I've had 4 over a 4 week period. Always on a cold start. Not just a little puff, quite a thick cloud for 5 -10 seconds. Dealer said 'keep track' of them. I haven't seen any loss of oil (or coolant) or change in performance. Car is under 80K warranty. Anyone else seen this? Next month is scheduled check.

Long story short, had a similar problem. 2017 Outback approximately 88,000 miles. Turned out I was not changing the oil frequently enough. Was due to clogged oil scraper rings. Had the top of the engine rebuilt and rings replaced (they need to dismantle the top of the engine to get at the rings). Cost was little over $4000. Runs fine now. Good luck.

 

[Rattlenbang]

Pcv valve usually causes increased oil consumption all the time, not puffs of blue smoke at startup. I'm think the latter example of clogged rings.

 

[Labradog13]

Also, mechanic said he is seeing this oil scraper ring issue in other makes and is wondering if manufacturers have changed the design or composition of the oil scraper rings.

 

[Rattlenbang]

Also, mechanic said he is seeing this oil scraper ring issue in other makes and is wondering if manufacturers have changed the design or composition of the oil scraper rings.

To achieve better fuel economy they engineered weaker piston rings so there's less scraping on cylinder walls. Add to that thinner oils and you get more oil burning in the cylinders, which causes more carbon buildup that clogs oil control rings.

 

[Raymond3006]

It has been YEARS since I've heard this complaint !
Congratulations : you are the PROUD Owner of a Vehicle that has a (one or MORE !) Piston Ring Sets that have not properly "broke-in" , and one or more rings that are actually ROTATING in the Piston Ring Groove(s) !!! When the spaces align, you will get a periodic "surge" of Oil-ByPass on one or more rings ! The amount of oil involved is VERY SMALL , and is usually ONLY noticed during cold-engine start-ups, after sitting a while , like Over-Night , or longer.

We used to fix this by using a SHORT DURATION NON-DETERGENT OIL ..... !

I have no idea if this OLD TIME SOLUTION would work in a "modern" vehicle Engine !

Unless it gets WORSE , you might be better off by LIVE-AND-LET-LIVE !

If you want to attempt to stop this periodic alignment of rotation(s) , I would ONLY keep the NON-COMPLIANT Engine Oil in the CrankCase for just 100-500-MILES ! Remember to use an appropriate Viscosity Oil , or you may cause other problems; the Driven Miles should be a mixture of driving , EXACTLY AS THEY USED TO SUGGEST FOR ENGINE BREAK-IN (circa , 50 years ago !) !!!!! Find a "History of Automotive Engine Break-In" , and have fun with a trip down Memory Lane of Streight-Sixes and American-V-8's !

 

[holdcraftm]

2020 Outback with 45K miles. I have experienced random intermittent blue smoke on starts for over a year. Sometimes once month, other times 2-3 months in between. This last two months I've had 4 over a 4 week period. Always on a cold start. Not just a little puff, quite a thick cloud for 5 -10 seconds. Dealer said 'keep track' of them. I haven't seen any loss of oil (or coolant) or change in performance. Car is under 80K warranty. Anyone else seen this? Next month is scheduled check.

Blue Smoke is oil burning. If still under warranty get your car into the dealer for a compression test and for a possible oil leak into your engine. Could be Worn Piston Rings, Damaged valve seals or a PCV valve problem.

 

[holdcraftm]

Blue Smoke is oil burning. If still under warranty get your car into the dealer for a compression test and for a possible oil leak into your engine. Could be Worn Piston Rings, Damaged valve seals or a PCV valve problem.

 

[Raymond3006]

Blue Smoke is oil burning. If still under warranty get your car into the dealer for a compression test and for a possible oil leak into your engine. Could be Worn Piston Rings, Damaged valve seals or a PCV valve problem.

Dealer - Dealer - DEALER !
Maybe he should stay OFF of Forums, and run like a scalded rabbit every time .... !

He is HERE , ... B/C ... he stated that he has ALREADY been in contact with the STEALER ..... !
And, apparently does not think that they have his best interest in-mind, or that they even have a CLUE !!!!