Help needed, Smoke issues.

[wilky]

Hi Everyone,
well it's been a while since I've been on the site mainly due to writing my previous Boxster off on the motorway in January 2013 in the floods.
At the time I was totally gutted and thought I'de never see Myself behind the wheel of another Porsche, but alas having since owned an Audi Quattro TT that came along at the right price I always hankered after owning another Boxster and decided to sell the TT and search for another Porsche, but this time the Boxster 3.2S.
I took my time and looked at a lot around the country and finally found one in a Basingstoke dealers that I was looking for with the right spec.
Everything seemed fine, yes there were a few things that needed doing to bring it up to my standard but apart from maintenance items all seemed very good and I was happy.
I picked it up and travelled home to Weston super mare being followed by my wife in her car, all was perfect until i got about 5 miles from home on the M5 and decided to put my foot down just to give it a blast and noticed that over certain speed plumes of smoke were exiting from the rear of the car up until then there was no smoke at all and on dropping the speed the smoke cleared.
I've run the car since and on start up there's no smoke, driving along the motorway theres no smoke, hit 90 and smoke is exiting from the back end slow down and its clear,
could this be a gasket thats failing and pushing oil onto the exhaust manifold/system, has anyone come across this before?
Any help or ideas would be much appreciated, I hope i haven't bought a lemon as i have no warranty as the mileage was over 90,000,

Regards, wilky.

[Anker]

Blue or black smoke?

Black smoke not bad. Mixture is overly rich, probably O2 sensors bad.

Blue smoke bad. Lots of oil getting into the cylinders.

You did read codes before handing over the money, didn't you?

[JFP in PA]

Originally Posted by wilky

Hi Everyone,
well it's been a while since I've been on the site mainly due to writing my previous Boxster off on the motorway in January 2013 in the floods.
At the time I was totally gutted and thought I'de never see Myself behind the wheel of another Porsche, but alas having since owned an Audi Quattro TT that came along at the right price I always hankered after owning another Boxster and decided to sell the TT and search for another Porsche, but this time the Boxster 3.2S.
I took my time and looked at a lot around the country and finally found one in a Basingstoke dealers that I was looking for with the right spec.
Everything seemed fine, yes there were a few things that needed doing to bring it up to my standard but apart from maintenance items all seemed very good and I was happy.
I picked it up and travelled home to Weston super mare being followed by my wife in her car, all was perfect until i got about 5 miles from home on the M5 and decided to put my foot down just to give it a blast and noticed that over certain speed plumes of smoke were exiting from the rear of the car up until then there was no smoke at all and on dropping the speed the smoke cleared.
I've run the car since and on start up there's no smoke, driving along the motorway theres no smoke, hit 90 and smoke is exiting from the back end slow down and its clear,
could this be a gasket thats failing and pushing oil onto the exhaust manifold/system, has anyone come across this before?
Any help or ideas would be much appreciated, I hope i haven't bought a lemon as i have no warranty as the mileage was over 90,000,

Regards, wilky.

More likely an AOS reaching the end of its life; you need to check two things: Your oil level (excessive oil level will sometimes cause this), and the vacuum level (in inches of water) at your oil fill cap with the engine idling.

[DrCactus]

Dropping your oil level down two notches on the display may help with the white smoke... as I was having that issue and after letting out some oil it was resolved. Granted when my car sat for a week or so between uses I would still have white smoke upon start up but from what I have read that is normal.

[jb92563]

Yep sounds like an AOS getting tired or too much oil in the engine.

If the O2 sensors are failing you would get the engine light coming on.

If no Dash warning lights its probably not any of the sensored things failing.

I would check codes from the computer in any case.

The AOS is not sensored so when it fails there is no indication except for a lot of smoke as extra oil starts getting sucked into the engine.

Also, make sure the oil level is down from full a couple bars just to be sure its not over full of oil.