My car isn't a daily driver. And for the last couple of years, once in a while, when I start it up to go for a drive after having it sit for a week or two or more... there used to be a big 'puff' of black smoke that comes out of the exhuast as I start her up. This always goes away once I start driving it around, etc. And when the car is warmed up and re-started after a stop somewhere, I don't notice the black smoke.

So, I chalked this up as something that happens upon a cold start after the car has been sitting for a little bit.

This last weekend, I was up at Thunderhill Raceway, driving both Saturday and Sunday, and someone noticed that as I started it up (after the car had cooled down for a bit and we had all packed up our cars and were ready to make the drive back home), that there was a puff of black smoke that came out from the exhaust.

1) what typically causes this ? And what is done to correct it ?
2) should I be concerned ?



Thanks,


Andy

 

It nothings to be concerned about becuase its only when its cold i would assume since thing contract a bit when they are cool your rings do the same so it burns a bit of oil??? not sure

 

Due to the whole flat 6 design, oil sometimes seaps into the cylinders if it's been sitting awhile, and is ignited upon start-up, causing the puff of smoke. No worries in most most cases. My Boxster does this occassionally, as does my 911 ('97 993 engine).

 

common known issue with the 911 engine and reported and seen by all of us. nothing to worry about and guess you will notice these cars can go through a quart of oil every 1000 miles

 

Happens to me once every 10-15 startups.... Nothing to worry about...

 

Thanks for all your encouraging words. Yeah... I know these cars are known for consuming oil... I'm still getting used to the whole 8 Quartz thing (not as bad as my friends 993TT ).

 

Because I am becoming feable with age...I can't remember the colors, but I thought white/blueish smoke was oil and black was coolant...could be totally off though. The above explanations are somewhat true for flat 6's being that it is oil. I suppose regardless if it is intermittent and only on start, perhaps no big deal...not sure, but maybe you should have it checked for leaks.

 

I am in the same boat about remembering, but I get a white/blueish smoke about every 6th startup. I have never had black smoke upon startup....just when I go WOT and shift into the next gear there is some black exhaust smoke coming out.

 

Typically:

blue smoke = oil
white smoke = coolant
black smoke = gas (or oil...depending)

 

yea, when you go WOT & shift gears, that black smoke is from your engine running rich for a split second

 

Exactly what mine seldomly does, but black smoke can also mean the turbo's are going no???

 

its possible, but i would think that turbos would be smoking all the time if they were going bad....


like i said, it is the engine running rich for a split second after you let off from WOT

 

yep blk is fuel to rich maybe just the warmup cycle... the old carb cars always blew black smoke at 5000ft... the thin air thus to much fuel and less air,,,,, god a forgot about all that stuff till now....

 

Andy- My car does the little puff of grey/blue once every 5-6 start ups. There have been many threads regarding smoke on start up and there seems to be just as many opinions on what causes it. Do a quick search... there's some good info there. If I were you, I'd keep an eye or get someone else to start the car so you can see what color the smoke REALLY is. I think if you're seeing black on start up, you may have additional issues other than the normal 911 oil usage and the whole flat-6 thing. Otherwise, dont sweat it and enjoy your car
PS. if you already don't, keep a mileage and oil-added log and look for consistency. My car goes thru 1.25 Qt of oil every 1500 miles. this way, I can monitor and see if the usage (and the oil) increases. Good luck

 

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