Wonderful. Blue smoke on cold start.

[thunderfog]

So... I start the Impreza this morning, and notice a puff of blue smoke from the tailpipe. Stellar. The car has about 32k miles, lots of it highway. It's the only time that I've seen it do this (but who knows). Before we jump on the valve guides, is there something else that could cause this?

The car runs on 6k mile OCIs per mfctr, and I don't lose any noticeable amount of oil between changes.

Anyone have any thoughts before I throw a coniption fit?

 

[thunderfog]

Let me add this. Last night, I had to start the car to switch places in the driveway. So it ran cold for about 20 seconds. Would this have anything to do with it?

 

[spasm3]

I would not worry, When i had an 01 escape i tried several different oil weights in it( spec'd for 5w 20). I noticed the 0w 20 oil and 5w 20 would do this after sitting. I think some of the 20w oil would sneak down the valve guides when hot,, then burn off when you cranked up the next time. I ran 5w and 0w 30 in it most of its life. I traded it at 175k with no engine problems( trans problems though).

 

[HerrStig]

My boxer BMW motor bike will blow a little blue smoke on startup from the LOWER cylinder when it's been sitting on the side stand (leaned over) for a few days. The flat four VW bugs used to do the same thing your Subie does when they got some miles on them. Dare I say try a thicker oil, in synthetic? I have one Camry I 4 which produced some startup smoke until I switched it to T6 from another very good oil. It had almost 200K on it at the time.

 

[Propflux01]

Originally Posted By: thunderfog
Let me add this. Last night, I had to start the car to switch places in the driveway. So it ran cold for about 20 seconds. Would this have anything to do with it?


Yes!!! I have had Several cars do this in the past ( various makes). The only time I'd worry about it is if the car does this every time you start it, warm or cold. Thicker cold oil gets caught up in parts not expanded and doesn't fall back down to the pan. Not every engine will do this but some will.

 

[goodtimes]

I had to replace the valve stem seals on an Accord, cleared up the problem. The old test is to go down a decent hill with foot off the throttle, then open the throttle wide and look for blue smoke. On my Accord it was a huge cloud of it. You're lucky your car should be under warranty if it is the seals.

 

[Pontual]

My scooby does that in a regular basis everytime the oil is up to the full mark or slightly overfilled. I think the high oil level find its way thought the cylinder bores and ring pack area, maybe. But did once or two I made 2 small moviments with the car cold, too. A fuel additive phase separating could do it, also. I believe that most cold smokes are blue (fuel or oil).

 

[Pontual]

Originally Posted By: thunderfog
Let me add this. Last night, I had to start the car to switch places in the driveway. So it ran cold for about 20 seconds. Would this have anything to do with it?


Yes it's possible excess fuel on the next startup.

 

[pb]

i don't know what the intake looks like on your car, but my issue with blue smoke at startup was due to oil in the intake from the pcv valve. a catch can fixed it.

 

[dishdude]

Originally Posted By: Pontual
Originally Posted By: thunderfog
Let me add this. Last night, I had to start the car to switch places in the driveway. So it ran cold for about 20 seconds. Would this have anything to do with it?


Yes it's possible excess fuel on the next startup.


I'm with this. Are you sure it was blue and not gray? Sometimes it's really tough to tell when you aren't expecting it and looking through the mirror. Unless it was like this...

 

[HerrStig]

Originally Posted By: Pontual
My scooby does that in a regular basis everytime the oil is up to the full mark or slightly overfilled. I think the high oil level find its way thought the cylinder bores and ring pack area, maybe. But did once or two I made 2 small moviments with the car cold, too. A fuel additive phase separating could do it, also. I believe that most cold smokes are blue (fuel or oil).
To much fuel (rich) is usually black rather than blue, when the cat hasn't lit off yet.

 

[CentAmDL650]

A high mileage or maxlife oil may swell the valve seals enough to stop the problem. Or if you wanted to spend (a lot) more you can get that effect with an ester oil.

 

[thunderfog]

Originally Posted By: dishdude
Originally Posted By: Pontual
Originally Posted By: thunderfog
Let me add this. Last night, I had to start the car to switch places in the driveway. So it ran cold for about 20 seconds. Would this have anything to do with it?


Yes it's possible excess fuel on the next startup.


I'm with this. Are you sure it was blue and not gray? Sometimes it's really tough to tell when you aren't expecting it and looking through the mirror. Unless it was like this...

I had actually stepped out of the car to get some shoes out of the hatch immediately after starting the car. It was definitely blue, and easy to tell against a background of snow.

 

[thunderfog]

Thanks everyone for the responses. I'll keep an eye on it for sure. I'm hoping PropFlux01's explanation covers it! Thanks again

 

[ABerns]

Yep, I will second PropFlux01. I've had several cars do this only in the scenario you describe. Rarely a full-time problem. I doubt you see it again after your normal driving.

 

[zpinch]

My CRV has (i think) some bad valve stems, from before i bought the car. It would occasionally have puff of blueish smoke at starup, not doing it at all since the temps have dropped, however. I was going to replace the seals this winter but it might be spring before it get around to it. Costs $1200 for honda dealership to do it.

 

[DBMaster]

I had the blue puff from my 1989 Accord due to stem seals or guides. Rotella synthetic 5W-40 stopped that and slowed consumption by 50% in an engine with over 300,000 miles. It did not negatively impact fuel economy noticeably, either.

 

[chrisri]

I had a 93 Civic Vti, 1.6, 160 HP. Bought from first owner, my dad's friend with only 110 k km. Maintained in Austria at official Honda dealer. At 160k km (100k miles) it started with blue smoke. Not to mention shocks, and wishbones.

 

[camrydriver111]

This is why I will be running Euro spec oil in all my cars from now on. [censored] CAFE!

 

[thunderfog]

Yeah. So it happened again today. I drove about 30 miles yesterday with plenty of time for the engine to get fully up to temperature. Again, only 32k miles on the car and I consider myself to be a decent driver. I'm easy on the RPMs until it's up to temp, I don't baby it, and I don't kill it either.

I suppose I will wait until it's a consistent thing before I take it in. It may be already; we'll see. I have the extended warranty so no worries on the mileage.