White exhaust smoke upon start up?
10-19-2013, 01:52 PM
#16
Race Director
Posts like yours show up every year at this time when the weather starts to cool and water vapor becomes more common at cold engine start.
Did the cloud dissipate quickly or linger/hold together? If the former the cloud was water vapor (mostly) with a small oil vapor component and probably normal.
Even if the cloud lingered as would be the case if it were almost all oil vapor this can be normal.
The oil comes not from past/around the rings but from a lousy, err inadequate AOS that let some oil vapor through to the intake the last time the engine was run. The vapor contacts the intake walls and becomes a thin coating of oil.
Over time this then drains down into one or more combustion chambers where it gets burned the next time the engine is started and the cloud of smoke you see comes from this.
Provided the cloud of smoke is brief and the engine exhibits no untoward behavior and the CEL remains dark the cloud is nothing to worry about.
What can contribute to the propensity of the engine to smoke like this is short trips, over filled oil, or oil that is past it change by date.
Now short trips mean the oil doesn't get hot and thus builds up a larger than normal load of unburned fuel and water. This does several things. It increases the volume of oil in the engine; it thins the oil and increases its propensity to foam and create more oil vapor when the engine is running which further overloads an already inadequate AOS (air/oil separator); and it accelerates the formation of acidic compounds in the oil.
For the above reasons the oil should be changed more often if short trips are the norm.
Oh, I note you park the car in a basement. Generally a basement can have a rather steep incline which can momentarily increase the oil vapor content of the oil in the crankcase as the oil in one head, under one camshaft cover runs to the end of the cover away from the oil scavenge pump and this results in the oil that accumulates under the camshaft cover getting whipped into a froth from the camshafts spinning and then when the car is on level ground the build up of oil is removed by the scavenge pump but this sudden rush of oil through the scavenge pump results in the creation of even more oil vapor which some then ends up on the intake walls. The engine is shut off very soon after and this vapor that has gathered of course drains into one or more combustion chambers and well, you know the rest.
Nothing you can do about the basement. You can let the engine idle a while (~30 seconds) but there is no real guarantee this will help, be enough time for the oil on the intake walls to run down and be burned in a hot engine. As the engine runs the wall are cool and the oil not so anxious to flow. Once the engine is shut off though the intake warms up from the heat from the engine below it and this warms the oil on the intake walls and of course it will then flow down and into the engine.
'bout all I can advise is you can certainly have a Bern Porsche tech check out the car/engine.
Be sure the oil level is ok. With the engine fully up to temperature the oil level can be at the max line but it should not be over this.
Consider changing the oil more often to cut down on the amount of thinning of the oil that occurs as unburned fuel and water accumulate from the short trips.
Did the cloud dissipate quickly or linger/hold together? If the former the cloud was water vapor (mostly) with a small oil vapor component and probably normal.
Even if the cloud lingered as would be the case if it were almost all oil vapor this can be normal.
The oil comes not from past/around the rings but from a lousy, err inadequate AOS that let some oil vapor through to the intake the last time the engine was run. The vapor contacts the intake walls and becomes a thin coating of oil.
Over time this then drains down into one or more combustion chambers where it gets burned the next time the engine is started and the cloud of smoke you see comes from this.
Provided the cloud of smoke is brief and the engine exhibits no untoward behavior and the CEL remains dark the cloud is nothing to worry about.
What can contribute to the propensity of the engine to smoke like this is short trips, over filled oil, or oil that is past it change by date.
Now short trips mean the oil doesn't get hot and thus builds up a larger than normal load of unburned fuel and water. This does several things. It increases the volume of oil in the engine; it thins the oil and increases its propensity to foam and create more oil vapor when the engine is running which further overloads an already inadequate AOS (air/oil separator); and it accelerates the formation of acidic compounds in the oil.
For the above reasons the oil should be changed more often if short trips are the norm.
Oh, I note you park the car in a basement. Generally a basement can have a rather steep incline which can momentarily increase the oil vapor content of the oil in the crankcase as the oil in one head, under one camshaft cover runs to the end of the cover away from the oil scavenge pump and this results in the oil that accumulates under the camshaft cover getting whipped into a froth from the camshafts spinning and then when the car is on level ground the build up of oil is removed by the scavenge pump but this sudden rush of oil through the scavenge pump results in the creation of even more oil vapor which some then ends up on the intake walls. The engine is shut off very soon after and this vapor that has gathered of course drains into one or more combustion chambers and well, you know the rest.
Nothing you can do about the basement. You can let the engine idle a while (~30 seconds) but there is no real guarantee this will help, be enough time for the oil on the intake walls to run down and be burned in a hot engine. As the engine runs the wall are cool and the oil not so anxious to flow. Once the engine is shut off though the intake warms up from the heat from the engine below it and this warms the oil on the intake walls and of course it will then flow down and into the engine.
'bout all I can advise is you can certainly have a Bern Porsche tech check out the car/engine.
Be sure the oil level is ok. With the engine fully up to temperature the oil level can be at the max line but it should not be over this.
Consider changing the oil more often to cut down on the amount of thinning of the oil that occurs as unburned fuel and water accumulate from the short trips.
10-19-2013, 03:19 PM
#18
Thread Starter
Thanks Macster for the very detailed explination.
10-19-2013, 07:22 PM
#19
Drifting
Posts like yours show up every year at this time when the weather starts to cool and water vapor becomes more common at cold engine start.
Did the cloud dissipate quickly or linger/hold together? If the former the cloud was water vapor (mostly) with a small oil vapor component and probably normal.
Even if the cloud lingered as would be the case if it were almost all oil vapor this can be normal.
The oil comes not from past/around the rings but from a lousy, err inadequate AOS that let some oil vapor through to the intake the last time the engine was run. The vapor contacts the intake walls and becomes a thin coating of oil.
Over time this then drains down into one or more combustion chambers where it gets burned the next time the engine is started and the cloud of smoke you see comes from this.
Did the cloud dissipate quickly or linger/hold together? If the former the cloud was water vapor (mostly) with a small oil vapor component and probably normal.
Even if the cloud lingered as would be the case if it were almost all oil vapor this can be normal.
The oil comes not from past/around the rings but from a lousy, err inadequate AOS that let some oil vapor through to the intake the last time the engine was run. The vapor contacts the intake walls and becomes a thin coating of oil.
Over time this then drains down into one or more combustion chambers where it gets burned the next time the engine is started and the cloud of smoke you see comes from this.
10-28-2013, 08:49 AM
#20
Thread Starter
So I have taken the car out a few times after the first cloud burst and after I spoke to my local Porsche garage (who gave me the green light to do so based on my observations).
There is still a little white smoke coming out the exhaust when I start the car, but nothing close to what I saw the first time. It seems like it doesn't matter how long (or short) it has to be turned off for the smoke to re-appear as I took it for a wash after a 2 hour drive, and 20 min of standing still was enough for smoke to reappear.
Anyway, service booked for the 7th of November so cross my fingers it will not be anything major.
Foot note: I called the official Porsche Zentrum Bern last week to hear if they could take the car in, but they had massive waiting list of over 2 weeks
There is still a little white smoke coming out the exhaust when I start the car, but nothing close to what I saw the first time. It seems like it doesn't matter how long (or short) it has to be turned off for the smoke to re-appear as I took it for a wash after a 2 hour drive, and 20 min of standing still was enough for smoke to reappear.
Anyway, service booked for the 7th of November so cross my fingers it will not be anything major.
Foot note: I called the official Porsche Zentrum Bern last week to hear if they could take the car in, but they had massive waiting list of over 2 weeks
10-28-2013, 09:06 AM
#21
a little rhyme from po smoke....sometimes cold sometimes hot.....sometimes alot sometimes not. disreguard the fairytales about parking it on a up/down/left/right tilt or idling for a minute. mine has /is been doing it from 09 when i bought it new. it is embarrassing at times and i stopped trying to tell people is normal. mine even did it the same day after a dealer oil change,at times it looks like a smoke grenade for a LZ. it has just over 20k on it now and only babied it for break in
10-31-2013, 08:21 AM
#23
New Pope?
Ah, couldn't resist....as always Mac has a great explanation and we all should be aware that these cars seem to develop personalities to a higher degree than other vehicles. I suspect we also pay more attention to them, and I agree that if the issue is intermittent and brief, don't worry....but for peace of mind, you can always shell out a few bucks and have it looked at.
Ah, couldn't resist....as always Mac has a great explanation and we all should be aware that these cars seem to develop personalities to a higher degree than other vehicles. I suspect we also pay more attention to them, and I agree that if the issue is intermittent and brief, don't worry....but for peace of mind, you can always shell out a few bucks and have it looked at.
10-31-2013, 12:35 PM
#24
Addict
Rennlist Member
Rennlist Member
Mine does it occasionally, especially if I am running it hard and then turn the engine off. Upon startup it'll happen.
Then at the track it almost always does it. It'll happen less if you keep the oil level low but it's still somewhat embarrassing.
Don't feel that bad though. I was on a mountain run with a brand new GT3 a couple of years ago. We went out to lunch and when we came back and he turned his car on there was a huge plume of smoke coming out of his car for about 5 seconds. Then it cleared up and that was the end of it. But imagine if you didn't know any better and you thought your $130k car just bit the dust?
Then at the track it almost always does it. It'll happen less if you keep the oil level low but it's still somewhat embarrassing.
Don't feel that bad though. I was on a mountain run with a brand new GT3 a couple of years ago. We went out to lunch and when we came back and he turned his car on there was a huge plume of smoke coming out of his car for about 5 seconds. Then it cleared up and that was the end of it. But imagine if you didn't know any better and you thought your $130k car just bit the dust?
