Very Foamy

Published in the August 2016 issue of “Die Porsche Kassette”

Ⓒ2016 Technolab /

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Very Foamy!                     by Pedro P. Bonilla (GCR PCA)


For more information on A/C foam and more, please visit my website:


Happy Porsche’ing,

There are two words that don’t go well together: “Porsche” and “foam”.

As anyone who has had a new (newer) Porsche for 4 or 5 years knows, the air conditioning vents start to spew bits of sticky dark stuff.  This stuff comes out of every A/C vent including the windshield defrost and the footwell heating outlets.

What is this?

With time, heat and humidity, all of the foam which makes up the air diverter dams in the A/C’s air handler system starts to deteriorate and crumble. 

As air is forced through, chunks of this foam starts to make its way to the air outlets and eventually make it out into the cabin.

There is nothing you can do preventively to avoid it short of not keeping your Porsches longer than 4-5 years.  The deterioration of the foam depends on several conditions:

Time: 4-5 years after the manufacture date it starts to deteriorate

Heat: The hotter the environment the quicker it will deteriorate

Humidity: The more humid the environment the quicker it will crumble

Therefore northern Porsches and those garaged and kept away from the sun and the elements will keep their foam a bit longer, but don’t get me wrong, even stored under the best conditions, if the car sees real world roads and conditions, that foam will deteriorate at some point.

When it starts to happen you will first notice some very small “dirt-like” particles on your clothing and on the interior (dash, seats, carpet, etc.).  As time goes on in a few more months you will notice the particles getting larger and larger and eventually you can see chunks of foam trapped behind the air vent slats.

Or, you can be patient, remove the foam chunks from the vents and wait.

You can use a small pick tool to pull out the pieces of foam through the slats.

But the best advise I can give you is what I tell my customers:

Wear goggles and don’t wear white!

What can be done?

You can open up the air handler system to remove and rebuild the air dams with new foam or tape (duct tape is used effectively) but this is very time consuming which can get expensive.

You can also help to purge the system quicker by closing all the vents but one, running the A/C fan at it’s highest setting and putting a vacuum cleaner nozzle right on the open vent.  Once this vent is cleared, close it and move to another one and repeat.