White smoke

[Hoopster]

Went to buy petrol today and when I started the car to drive away from the pumps it produced a substantial cloud of white smoke; I mean embarrassingly substantial [] - the car behind me disappeared completely and the forecourt was quickly shrouded in smoke.

Reading around the comments on the forum, there are some suggestions that this is "normal" .... I'm finding that rather hard to believe. Can't imagine Porsche selling as many vehicles as they do if they behave like that normally.

The engine was warm and I had been driving for about 20 mins prior to this happening. Fortunately Guildford OPC was half a mile along the road so I've dropped the car in there and await their assessment.

Meanwhile I'd be interested to hear your views on possible causes (burning oil, antifreeze, blown gasket..??)

Hope this doesn't prevent my trip to Paragon in three weeks...

Cheers
Adam

 

[944s2]

Surely not wrong fuel?

 

[Hoopster]

No - Not unless the V-Power unleaded pump was dispensing something else.... but you did just make me double check on my receipt []

 

[Motorhead]

White smoke generally indicates water vapour Adam.

Did you have a chance to check the coolant level and was the temperature above 90deg C? Maybe a head gasket's gone.

Glad you made it to the OPC for an appraisal - hope it's nothing too serious.

Jeff

 

[Hoopster]

Good call - I didn't think to check the coolant level, but the temperature was normal per the gauge, and I had no warning lights on the dash.
I've heard that antifreeze can cause white smoke, so your coolant/gasket suggestion sounds entirely plausible...

 

[Motorhead]

Sometimes the gauge isn't necessarily an accurate guide to what's going on until the temperature starts to rise rapidly - usually too late..! However, no coolant warning light means that the header tank level was OK.

The upside is that your Boxster has a lot of coolant (more than 20 litres) - large radiators and long pipes running front to rear - so a small coolant loss isn't a problem.

Keep us posted on progress.

Jeff

 

[ashley]

Air Oil separator, had this go on my first 996 and it was like a scene from James Bond,

 

[Richard_Hamilton]

^^^^^. What Ashley said. Best get it checked before it contaminates the oxygen sensors.

 

[Peter_Bull]

ORIGINAL: ashley

Air Oil separator, had this go on my first 996 and it was like a scene from James Bond,

happened to me with my then 996 - fortunately it happened inside the OPC garage as they were about to drive it out to me! Filled the whole garage with white smoke! Air Oil Separator.

 

[Motorhead]

ORIGINAL: Peter Bull

ORIGINAL: ashley

Air Oil separator, had this go on my first 996 and it was like a scene from James Bond,

happened to me with my then 996 - fortunately it happened inside the OPC garage as they were about to drive it out to me! Filled the whole garage with white smoke! Air Oil Separator.

Like this?...!

http://sites.google.com/site/mikefocke2/airoilseparatorreplacement

Hopefully, no damage to the O2 or MAF sensors and the cats.

Jeff

 

[Peter_Bull]

ORIGINAL: Motorhead

ORIGINAL: Peter Bull

ORIGINAL: ashley

Air Oil separator, had this go on my first 996 and it was like a scene from James Bond,

happened to me with my then 996 - fortunately it happened inside the OPC garage as they were about to drive it out to me! Filled the whole garage with white smoke! Air Oil Separator.

Like this?...!

http://sites.google.com/site/mikefocke2/airoilseparatorreplacement

Hopefully, no damage to the O2 or MAF sensors and the cats.

Jeff

Hi Jeff - worse than that believe me! Luckily for me it happened in the OPC!

 

[Hoopster]

Considerably worse than that in my case too ! And it was definitely thick white smoke.
OPC called to say they will look at it on Friday (booked up until then) so it's going nowhere until I get their diagnosis...

I am certainly no engineer, but how would an Air/Oil Separator failure cause white smoke ? Would that not cause oil burning and blueish smoke? White smoke suggests water/antifreeze not oil ???

Whatever the fix, I'm rather hoping that it's covered be the warranty[&:]

 

[Motorhead]

ORIGINAL: Hoopster

Considerably worse than that in my case too ! And it was definitely thick white smoke.
OPC called to say they will look at it on Friday (booked up until then) so it's going nowhere until I get their diagnosis...

I am certainly no engineer, but how would an Air/Oil Separator failure cause white smoke ? Would that not cause oil burning and blueish smoke? White smoke suggests water/antifreeze not oil ???

Whatever the fix, I'm rather hoping that it's covered be the warranty[&:]

My thoughts too Adam.

White smoke: water/antifreeze. Blueish smoke: oil. Black smoke: fuel.

Still, people on here with first-hand experience, so can't refute that.

And AOS replacement is relatively straightforward, so you could have her back on the road in time for a weekend run....result..!!

Jeff

 

[Richard_Hamilton]

When the air/oil separator fails (it usually splits internally) oil vapour from the crankcase is drawn directly in to the throttle body. This burns in the cylinder and produces volumes of white smoke out of the exhaust. It does have a slightly blue-ish tinge, but it looks white, especially in bright sunlight. It isn't the same as neat engine oil burning, caused by, say, worn valve guides, which gives a black-blue smoke. Not all the vapour burns, and if you put your hand next to the exhaust, it feels oily to the touch. It is this unburnt vapour which can contaminate the heated oxygen sensors - it can burn on to the surface. The MAF isn't affected, because it is upstream of the throttle body.

 

[Motorhead]

Many thanks for the succinct explanation Richard.

Hopefully a fairly rare occurence but something to watch out for all the same.

Jeff

 

[Hoopster]

Sorry for my silence over the last few days - I've been out of the country. Thanks to all for the technical insights - being a rather non-technical person myself, having the expertise of other forum members at my fingertips is very much appreciated.

So the OPC came back with their verdict late yesterday, and it's full marks to those of you who diagnosed a failure of the air/oil separator ! Coolant levels were fine. I'm now awaiting a price quote, but the indication was that this would be covered by the warranty.

Hopefully get the car back on Tuesday. []

 

[ashley]

Good news Adam, when mine went it was covered by the Porsche warranty

 

[Hoopster]

All fixed under warranty. So there's a result.
Interestingly the pick up and acceleration are noticeably smoother now, particularly in first gear: There must have been a fault for a while, but I hadn't noticed the progressive deterioration. Presumeably the engine management system would also try and compensate up to a point too.
Anyway - feels like driving a new car after a week away, and the sun came out and the roof down on my drive home.... happy days !