2000 996 carrera 2 coupe 6 speed - A/C Airbox doors

[Philip54]

I need to replace the foam of the flap doors of the airbox of my car.  The existing foam has deteriorated and is coming out of the dash vents. A common problem on 996s that has been discussed on this site in other occasions.

After getting the doors out and removing what is left of the existing foam from the door metal frames, I would like to use 1/8” thick close cell foam and mylar adhesive tape for the replacement.

I am considering foam with the following specifications:

Foam A

Weather-Resistant Neoprene/EPDM/SBR Foam

Foam, but not adhesive, meets ASTM D1056 2A2, UL 94HF1, and UL 94HBF. Material has a fine cell textured finish and does not have a skin. Adhesive is rubber based and has a temperature range of –10° to 150° F

Weather and abrasion-resistant foam rubber

 

Foam B

Weather-Resistant Ultra-Conformable Vinyl Foam, Sheet, Ultra-Smooth Texture

Material                                       Vinyl Foam

Cell Type                                     Closed

Texture                                        Ultra Smooth

Thickness                                    1/8"

Pressure to Compress 25%        5 psi

Backing Type                              Plain

Hardness                                     Extra Soft

Temperature Range                    -30° to 160° F

Density                                        9 lbs./cu. ft.

RoHS                                          Compliant

 

I would appreciate any comments on my proposed method and suggestions on whether to use foam A or foam B  (or other types of foam).

 

Many thanks

[creekman]

Since you brought it up I know earlier posts have blown off the idea of replacing the foam.  I've been picking it out of my vents for several months now.  However, the cold air doesn't immediately get cold,  some times it takes 10 minutes before it really starts blowing cold.  Could this be the lack of foam on the doors or something else?  What does the foam accomplish?

 

Thanks,

 

Mitch

[Philip54]

7 hours ago, creekman said:

Since you brought it up I know earlier posts have blown off the idea of replacing the foam.  I've been picking it out of my vents for several months now.  However, the cold air doesn't immediately get cold,  some times it takes 10 minutes before it really starts blowing cold.  Could this be the lack of foam on the doors or something else?  What does the foam accomplish?

 

Thanks,

 

Mitch

 

The airbox door metal frames have large holes on them.  Without the foam the air goes through the doors doesn't matter if they are closed or open.  When the foam starts deteriorating, initially you just get pieces of foam through the vents.  Eventually when most of the foam is gone, the A/C heater system stops working properly.

Access to these doors is difficult.  A lot of parts need to come out to get to the doors.  Because of this it is important to select a reliable repair method for the doors, whether you use foam or not.

[DBJoe996]

My experience with this is the foam deteriorated and came out the vents.  After awhile it stopped doing it.  Put the HVAC fan on high and I took a shop vac to the vents and tweezers to pull out the bits.  Several times of this and it all stopped.  I have never had a problem with AC cooling or heating after all this, and it has been years now.  I do appreciate someone undertaking a repair of the foam, but I do not see the point as it will also deteriorate with time.  Just one of those things.

[creekman]

Philip,

Thanks for the reply, when you decide on which foam you're going to use would you post your choice and the vendor who can supply it?  Is there a definite link that shows how to get to the A/C doors?  I bet the dealer would get $600-$1,000 to do that work?

 

Thanks,

 

Mitch

[creekman]

Joe,

 

I have done the same thing, but the A/C has a good charge and it works well, but not until you have the fan on high and finally it starts cooling.  So I thought there might be some connection between the foam and the slow cool...

[JFP in PA]

Usually, there is a connection between the foam issue and AC cooling.  Because these heaters are always hot, air leakage of heated air into the AC system can defeat the AC and give you lukewarm air.  Correcting the foam usually brings the AC right back.

[creekman]

Thanks, I wish that was not the case and I wouldn't have to deal with it, but at least I know what the A/C is doing, or not doing.  I've hit the search button with just about every combination I can think of for info on getting to the A/C doors without success.  "How to remove the A/C doors", "Replacing the foam on the A/C doors", etc.  

 

I know this has been talked about so the information is here, please pass on any links that would be applicable...

 

Thanks,

 

Mitch

[DBJoe996]

There are a couple of links in this thread and what people did to replace the foam 

 

[Philip54]

9 hours ago, creekman said:

Philip,

Thanks for the reply, when you decide on which foam you're going to use would you post your choice and the vendor who can supply it?  Is there a definite link that shows how to get to the A/C doors?  I bet the dealer would get $600-$1,000 to do that work?

 

Thanks,

 

Mitch

 

Mitch,

 

I will post the information on the foam, if I go for the replacement.  I would like to give a try to the idea proposed by DBJoe996 even if it did not work for you.

As far as the cost of the repair, I believe that if the normal procedure, which involves removing the dashboard, is used, the cost will be well above $1,000.  If the airbox is accessed from the trunk only, I don't have any idea about what the cost could be.  But I personally doubt that a dealer would go that way.

[Philip54]

10 hours ago, DBJoe996 said:

My experience with this is the foam deteriorated and came out the vents.  After awhile it stopped doing it.  Put the HVAC fan on high and I took a shop vac to the vents and tweezers to pull out the bits.  Several times of this and it all stopped.  I have never had a problem with AC cooling or heating after all this, and it has been years now.  I do appreciate someone undertaking a repair of the foam, but I do not see the point as it will also deteriorate with time.  Just one of those things.

 

Joe, 

Thanks for tip.  I will give it a try before I go for the foam replacement.

[creekman]

DBJoe,

 

Thanks for the links, this problem goes back a long time.  I find it hard to believe that the A/C system is going to work the same way without the foam, as bad of a solution the foam is, it must have a reason for being there.  However, I really don't want to have to get into it if I don't have to.  However, it appears to me that my cooling has been affected so maybe the foam gods are calling me.

 

I have my car for sale so it needs to be done I guess... 

[jlr2004c4s]

I have had this foam issue for 2 to 3 years.  I line in the Northeast where humidity and heat are a problem.  I now need to address problem since the windshield fogs up while running the AC with the vent selected.  This is because the windshield diverted door has now deteriorated as well.  

 

My question is...can I get both doors by undoing the servo-arm above the passenger foot-well and then proceeding to the outside cowl area OR do I need to remove the dashboard to access the entire heater box??  I have read through several threads and I'm not certain that the 996 C4S procedure is the same as the 996 C2 or Boxter....

 

Thanks for any help...

[creekman]

I have a '03' C4S and the posted Tech Tip didn't work for me.  I think there is a difference here between the Boxster style

airbox and my 996 C4S.  In my case, the dash will have to come out to split the airbox to remove the door in question.

My humble advice is to start the 'Tech Tip' from inside the car to remove the door.  I got everything done on top, all looked good

until I tried to follow through with the directions to remove the bottom pivot.  It ain't coming apart...

 

Our local Porsche dealer wanted $1,100 to do the job...

[Philip54]

8 hours ago, creekman said:

I have a '03' C4S and the posted Tech Tip didn't work for me.  I think there is a difference here between the Boxster style

airbox and my 996 C4S.  In my case, the dash will have to come out to split the airbox to remove the door in question.

My humble advice is to start the 'Tech Tip' from inside the car to remove the door.  I got everything done on top, all looked good

until I tried to follow through with the directions to remove the bottom pivot.  It ain't coming apart...

 

Our local Porsche dealer wanted $1,100 to do the job...

 

Creekman, thanks for the update.  I have not yet had the A/C doors replaced.  I have been travelling on business and I have not used the car much.  I have gone so far as re-covering the frames of my spare doors with new foam.