White Smoke on Start Up

Hi All, I know this has been discussed before but I don't think it was ever concluded, so here I go again. Occasionally on start up my 2007 2.7 Boxster (now 41,500 km) blows out an embarrassing amount of white (oil?) smoke. It only does it at initial start and doesn't seem to really use oil between 10,000 km changes. It does seem to do it more often when left parked on an incline but still does it sometimes when parked on a flat surface. I remember once parking for about 6 hours on quite a steep uphill slope and it looked like a bushfire when I started the car. I have asked my mechanic (T&D Automotive) about this and he said it can be the AOS (Air - Oil Separator) but can also be other things. Do any of you knowledgeable people have any experience or thoughts to share on this?

White smoke generally means coolant/water is burning. white = steam. oil is light blue, blueish colour.

Hi Steve, I have read somewhere that a puff of white smoke from start up is not unusual. My 2007 Boxster has done it a couple of times but not regularly. The day i picked it up fro  the dealer (I nearly died) and one other. I thought it was as a result of sitting for a period of time but i'm not sure. I wouldn't panic just yet

my mates BMW 545i e60 does the same thing. on idle for over 5 min it'll start smoking. I think it's a head gasket problem. but can't be to sure.

As another Boxster owner I can confirm I have experienced this on the odd occasion.  As Bafe, said, first time is heart attack material but upon a bit of research I did find that this can be quite normal if occurring on the odd occasion.  Not at every start up though!  From memory it can be a property of the M96 design and you mention that the car is parked on an incline which could adding to it. Check out 986forum,.com as there are a few people there that cover this too.

I seem to remember Niko had an issue with this as well but it was fixed. Is that right Niko?

my cayman occasionally produces a very small amount at start up, which I am told is normal... I think your car is fine.. I wouldn't worry. I'd try parking mine on a steep hill to see if it will do the same as yours, but I know how much the oil cost me and don't want to waste any!

yeah, have a look at Niko's post - something about a recirculation system getting clogged up (there's a solution in it too) sounds a lot like the air/oil separator though paging @Niko EDIT: dang, this version doesn't let you notify people

You can notify people? How do you do that :|

other versions of forum software lets you notify users of a post similar to twitter. don't think it works on here though

I think Nikos was the AOS.  But he'll confirm when he arrives in here. Mine has never blown smoke BUT I get the other scary but perfectly normal M96 thing -  the timing chain tensioner rattle (is that the right terminology?). It's the kind of sound that when you first hear, you want to rush out and trade it on a Mazda!  But a bit of research showed that it's perfectly normal. In fact it's working as designed!

It's normal for your car to "clear its throat" very occassionally.  If it gets worse, then it's the air / oil seperator which needs servicing. The engine air-oil separator is an emissions device that is responsible for collecting residual gases and vapours contained inside the crankcase and funnelling them back into the intake manifold where they can be burned in the combustion chamber. This reduces the overall emissions of the engine. When the separator fails, you will begin to see a large increase in the overall vacuum in the engine crankcase. In the most extreme cases, the air-oil separator fails to separate the oil from the air and oil is then sucked into the intake manifold. Oil in the intake system is not healthy for the engine and it can foul spark plugs and destroy catalytic converters at the very least. The failure of the air-oil separator is often but not always, accompanied by huge amounts of white smoke exiting the vehicle's exhaust and a generally poor running engine. You may experience a check engine light (CEL) as the oil being drawn into the intake can affect the mixture level. The oil cap may be very difficult to remove when the engine is running due to high vacuum levels. In addition, you may hear a high-pitched squeal from the engine when it's running because air is being sucked in past the crankcase seal due to the extreme vacuum inside the case.

Thanks peeps, it started to occur a little more frequently since the last service and I started to get that "worried about my bank balance" feeling. I will get the AOS checked at next service or if it happens more frequently in the meantime. As stated, not all the time which is reassuring that it's not something drastic.

Sorry sorry been a bit slack picking up here. Tomos I will be pretty sure it is your AOS, your description of it being embarrassing is the best description I could give for the AOS. Your description of when etc was the same as mine, having said that mine although very light in colour would say it was more blueish. It is not a good idea to leave it for too long to fix. It is not expensive I think from memory $120.00 or around that maybe a bit more, I can get the exact price, if you need it. The latest Pelican Parts update which came through a week ago or so talks about the problem but relates it to the 996 engine. I f you can't get it or find it let me know and I will try and post the article up Again apologies for late reply here, And also again I have no doubt it will be the pesky AOS, very common problem for our cars. Good luck with it.

Further to that Cavers explanation is spot on

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Caver's explanation was clipped from the Pelican Parts Update!

Thanks Niko and Caver, I will have a browse around Pelican Parts site and see what I can find. I would like to be able to do something on the car myself apart from drive it and put petrol in the tank so hopefully it's a reasonable DIY fix.

This may help... http://www.pelicanparts.com/techarticles/Porsche-996-997-Carrera/09-ENGINE-Air_Oil_Separator/09-ENGINE-Air_Oil_Separator.htm?utm_source=pelican_porschenewsletter&utm_medium=email&utm_campaign=20140122

Geez there's fantastic info on the PP site!  Although, sounds harder again to remove from boxster engine due to the location and inability to access engine components? Does anyone know how long the AOS lasts or what the replacement interval is on it?

the comments on the pelican article are worth reading too - mileage varies apparently. There is a motorsport one that is "better" (but nobody can say why definitively) I had a look round the 'net for replacement interval, I think its something you change when it goes bad

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Part number 996 107 926 00. It would want to be better - it costs around 9x the price of the regular one.

The "motorsport" option has twin chambers. And, as Just James said around 9 times the price of the standard one, I think the standard one will work just fine. I really don't need the extra chamber for another $600 or so!

My p started this yesterday. Id been aware of the issue before purchase. Pelican has one on the way $125 delivered. Freight being $50.50 now. I'm sure I can fit it and save a thousand or so. Stealers prices and knowledge are disrespectful to say the least.

Gee, it's a big hit on the freight....for the size of the AOS itself. I think I said it cost me $120 and that was through the business that look after mine. That was the price of the actual AOS replacement part. fitting surprisingly is not that expensive, from memory. Only $140.00 or similar. Good luck with it.

My money is on the air/oil separator.  I would also be looking at my plugs.  They tell you are great deal. New ones can make such a difference.  I had a Cayman 2.7 but I must admit I am not sure how easy they are to get at.

AOS is a reasonably easy job on the 986's  according to my workshop.  (Easy for him to say though) Not being too Porsche mechanically minded myself though, it would probably be a monster job if I stupidly took it on.

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Yeah has the classic high vacuum at the oil cap as well. Not an easy one but I enjoy the challenge. I'm not Porsche mechanically minded but I'm learning. Pelican has a good tutorial as usual. With his and others gives a well rounded look at the job before hand.

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Thank you so very much mate, you're a saviour. This happened to me this morning, the smoke and all, but it started with the loud embarrasing squealing sound in the middle of the city on Wednesday night. After that I drove home as if nothing was wrong but this morning, I could have easily been sending smoke messages to the Indians, thinking it was a blown gasket or something more sinister. I will hope it's the AOS which is not a bad fix. Thanks to all guys.

Hi Bobbyg, welcome to our forum. Hopefully..and it certainly sounds like the AOS Please come back and let us know how you went. An update on how much the job (if it is the AOS) now costs would be good too. Good luck with it

Hello everyone, I am a Newbe to this Forum and you guys sure seem to know your stuff, I have a 2010 Boxster S and have the White smoke on start up problem also, but after sitting in the Shed for the last 4-5 days I went out on purpose to start the car and had my stop watch ready to see how long the white smoke came out before it stopped, because it smokes for awhile then seems to stop, anyway I started the car hit the stop watch and jumped out of the car to go and have a look and time how long before the smoke goes away, but this time it dident smoke at all, not at all I am going to get it fixed next week when I take it for a service. My question to you guys should it be OK to drive it 450 Ks to the service center or not. Regards Sean.

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Smoke on startup quite normal, particularly if it has sat for a few days.  Easy solution, drive it every day 🙂 Seriously though, do a search on this forum and on the 'net generally, and you'll find heaps of similar questions and answers.  And welcome to the forum 🙂

I got a 2.9l DFI boxster with the AOS done.  Did 4 track days over 8 days and about 3,000 klms of hard driving in between and about 2/3 the way through I'd occassionally get white smoke on start up.  Threw it at the mechanic after the tour was over and he couldn't replicate.  Sounds like a 'thing'.  My car runs great.  No issues at all.  Thrashed the balls off it.  You'll be right.

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Looks like I’ll be talking to you when the time comes 🙂

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I'll be here....I'm not allowed to go anywhere

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I mean in relation to 'white smoke ' coming out of my exhaust.

Smoke on start up is an event from time to time on all the flat 6's, especially 996 Turbos (no AOS) which have a different cool down technique required to clear the turbo oil feed check valves.  White smoke and copious amounts of it however is a different matter.  A decent mechanic can check the capacity of the AOS to hold a vacuum.  If it is on the way out its not a difficult fix.

Update on my white smoke.  I had the car serviced yesterday and after replacing the AOS, the smoke is gone.  I've only done the single start when I picked the car up so far and will do a few more checks of the next week or so.

I should report back that after about 8 or 9,000km it is still fine.  Only used about 500ml of oil in that time.