Boxster smoke from dash vents
 

Hi guys.
S0, 6 months of happy driving after getting the transmission sorted and now I move on to the next issue just hoping it won't be as costly as the last...

I started driving and noticed a strange smell and that the cabin was getting a little foggy.
I pulled over, wound windows down and stopped the engine and noticed smoke coming from the vents.
Now I've had the dreaded "foam through vents" thing for a while and considering the car was stood for around 3 weeks, just thought it was a build up of foam?
No. Everytime I drive now, the smoke appears.
Things I've noticed:-
You don't see it too much if the AC/heating/cooling fans are on.
When the car is turned off, the smoke continues to come through for around 3-5mins.
(the video linked is when the car engine was off)
The smoke seems "dusty" rather than thick
No oil is leaking for from the car. (been sat for a couple of weeks since I first noticed and ground totally dry.)

I've not changed cabin filters of given the car a service since I got it 12months ago so not sure if thats a contributing factor.
Can't seem to find anything in the 101 projects which may enlighten me.
As always, your help and comments are appreciated.

I'm scared to drive the car far in case it is a serious problem (I'm not stupid enough not to know any kind of smoke is probably bad!)

Cheers
Mike
https://www.youtube.com/watch?v=VWJRBCHxlK0
https://www.youtube.com/watch?v=VWJRBCHxlK0

You are right, any smoke is not good. Does it have a smell of any kind? How soon does it start smoking after starting the car from a cold state? Are there any electrical issues of any kind like lights or stereo or any equipment not working? Have you taken any OBD code readings?

Tracing this down might be difficult until all the conditions are known. My advise would be to take it to a really good indie who has been exposed to a lot of Porsches. These guys see a lot of issues.

Heatcore behind the dash center vent may be leaking hot steam of coolant?

Are you sure its smoke and not steam? Steam coming out of the vents is a symptom of a plugged heater core drain.

Thanks for the replies.

It could be steam I guess as it evaporates a lot quick than smoke would. It does have an smell although i've dealt with enough electrical burnings to not think it's an electrics issue.
It doesn't kick in immediately the engine is started but does happen not long after things warm up. Today I started, left it running a few mins before a 5 mins trip to fill up.
By the time I got to the garage, when I shut off to let the guy fill up it started seeping from the vents.

How do I check for a plugged or leaking heater core drain?

See if it will fog a mirror. Steam will but smoke will not.

It is steam. Clean the evaporator and heater core drains. If you don't it will start growing mold in there and it will stink and affect your health.

Check your coolant level. Heater core hole would allow water/mist into the vents. What does it smell like?

Were either Cheech or Chong previous owners of your vehicle? If so, the answer is obvious!

A little Monday morning humor...

This happened to me recently and I replaced my heater core. Check the passenger carpet. My passenger carpet was wet from coolant leaking.

I had same problem in a different car, the heater core broke where the hose attatched the coolant gets into the venting system looks like fog blowing out. Wierd looking.