Subaru Crosstrek and XV Forums banner
1 - 20 of 22 Posts

·
Registered
Joined
·
162 Posts
Discussion Starter · #1 ·
Hi All,

Did some searching but not finding anything relevant or conclusive. In the last few months and on a handful of occassions, my 18 limited with 68k miles has coughed up a whitish/greyish/not quite blueish puff of smoke for a second or two on starts. This even when temps are high/moderate and the engine had been previously running during the day. The dealer is baffled and since it only happens once in a while, hard to reproduce or predict. Dealer checked the PCV valve and it has been replaced under the recall already long ago... additionally it wasn't wet showing any sign of failure. Yet, here we are. Any ideas or anyone with similar experience? I'm not documenting any fluid loss either water or oil... stumped.

Thanks in advance.
 

·
Registered
2019 Subaru Crosstrek Limited
Joined
·
979 Posts
Carbon build-up? I'd expect carbon build-up at that kind of mileage.
 

·
Registered
2019 Subaru Crosstrek Limited
Joined
·
979 Posts
Complete title: Cleaning Procedure for Carbon Deposit Removal to Address Engine Misfire DTCs, Black Smoke from the Exhaust, Lack of Power, Knocking (Ping) and / or Rough Idle Concerns

MC-10201059-0001.pdf (nhtsa.gov)


Covered under 5yr 60k mile powertrain warranty.
Here's a video of the procedure on a 2015 Forester:
Using Subaru Carbon Clean on my 2015 Forester XT - YouTube
In the TSB, it mentions black smoke but it could be something to consider with the mileage you're at.
 

·
Registered
Joined
·
162 Posts
Discussion Starter · #10 ·
In the TSB, it mentions black smoke but it could be something to consider with the mileage you're at.
Thank you for this... I have a service appt next week to have them do an evaluation. The hardest part of this is like chasing a ghost. No telling when it will happen.
 

·
Registered
2019 Limited with Eyesight
Joined
·
428 Posts
Blueish smoke usually means burning oil. A compression test is a good start.
The most common cause of blue exhaust smoke is oil leaking past engine seals and into the cylinders where it then mixes and burns with the fuel. ... Blue exhaust smoke only at start-up can indicate worn piston seals or damaged or worn valve guides which may also cause a rattling noise.
 

·
Registered
2019 Subaru Crosstrek Limited
Joined
·
979 Posts
Thank you for this... I have a service appt next week to have them do an evaluation. The hardest part of this is like chasing a ghost. No telling when it will happen.
Do you have an extended warranty from Subaru?
 

·
Registered
Joined
·
434 Posts
Oil control rings are probably filled with carbon. I wouldn't check pcv on these, just replace(inexpensive insurance and a pain to get to). You might consider running a couple bottles of Chevron Techron Concentrate through the petrol with a long highway drive(s). I'd also use the 5w-30 full syn oil instead of the llighter weight 0w-20.
If there was "white" smoke, would have been interesting to see what the old plugs looked like. I'd keep an eye on the coolant level. Sometimes, flat engines will give a puff of smoke on start up. Our Boxster will do it very rarely if it's sat for exceedingly long periods.
regards
 

·
Registered
Joined
·
162 Posts
Discussion Starter · #15 ·
Oil control rings are probably filled with carbon. I wouldn't check pcv on these, just replace(inexpensive insurance and a pain to get to). You might consider running a couple bottles of Chevron Techron Concentrate through the petrol with a long highway drive(s). I'd also use the 5w-30 full syn oil instead of the llighter weight 0w-20.
If there was "white" smoke, would have been interesting to see what the old plugs looked like. I'd keep an eye on the coolant level. Sometimes, flat engines will give a puff of smoke on start up. Our Boxster will do it very rarely if it's sat for exceedingly long periods.
regards
I have a drive at the end of the week and might just try this. Simple.
 

·
Registered
Joined
·
162 Posts
Discussion Starter · #17 ·
If they perform the decarb as per the TSB it's covered under warranty.
Thank you for that... I will print up the TSB and have it in hand with me when I come in. I have a drive this weekend in the mountains over about 90 mins or so... may also try a jug of techron as suggested. Can't hurt.
 

·
Registered
2016 Crosstrek
Joined
·
1,407 Posts
Thank you for that... I will print up the TSB and have it in hand with me when I come in. I have a drive this weekend in the mountains over about 90 mins or so... may also try a jug of techron as suggested. Can't hurt.
Get the bottle that treats 20 gallons. The bottles at Walmart are typically smaller.
 

·
Prefers black cats
'18 and '19 Crosstrek Limiteds
Joined
·
13,234 Posts
If they perform the decarb as per the TSB it's covered under warranty.
TSBs are simply instructions for how a dealer should perform a service item. They are completely different from recalls, which have no warranty requirement.

A dealer will likely charge for a TSB unless there's some agreement with Subaru that it be covered, especially on an '18 with 68K miles, unless you have an extended warranty.
 

·
Registered
2019 Subaru Crosstrek Limited
Joined
·
979 Posts
TSBs are simply instructions for how a dealer should perform a service item. They are completely different from recalls, which have no warranty requirement.

A dealer will likely charge for a TSB unless there's some agreement with Subaru that it be covered, especially on an '18 with 68K miles, unless you have an extended warranty.
If you read the earlier posts he has an extended warranty.
 
1 - 20 of 22 Posts
Top