Heater box and airducts- and their internals

[eriknetherlands]

Taking apart my heaterbox and airducts. All came out relatively easy, now all on my table.

I see that inside the main duct ( the one coming straight at you, below the control panel) there is foam + textile glued in. Is this original?
The white foam underneath looks to me.

Can anyone confirm what is supposed to be inside, if anything?

 

[deQuincey]

Taking apart my heaterbox and airducts. All came out relatively easy, now all on my table.

I see that inside the main duct ( the one coming straight at you, below the control panel) there is foam + textile glued in. Is this original?
The white foam underneath looks to me.

Can anyone confirm what is supposed to be inside, if anything?

it is original yes,

and it is the crappyest thing you can ever seen inside the coupes


my assumption is that the yput the foam to absorb air noise and more important the noise comming from the front area including engine noise
the textile is to keep the foam in place
the mouth of each duct had felt around to seal against the next element

i would replicate it, and i did it successfully, but lost the pics

 

[Mark Jarman]

@eriknetherlands I can second what @deQuincey wrote. My heater internals looked exactly like your pictures. I was a little mystified by the whole design and didn't understand the intended function of the foam and fabric so I just cleaned everything really well and re-glued the fabric to the edges using contact cement. I also glued new felt around the edges.

If you come up with any upgrade / improvement ideas please post.

 

[eriknetherlands]

Thanks guys,

Original, then ill keep it. The textile and foam are still in a remarkable, clean condition. I will just reglue them.
Also the felt pieces mentioned by Dequincey are still on each joint.

It is a surprising construction, as i've worked in vehicle interior engineering, and i have never come acros it in over 20 years. I think it would it would just reduce the volume going through it. Perhaps due to the extra airfriction (narrower path) the motor even has to push harder.
Regarding upgrade; i'm leaning towards just ripping it out. Larger ductsize, lower airspeed, less turbulance, lower noise...I think...

Second question , about the air vents near the feet. My car had a metal grille, diverting the airflow only one side. The other side did not. See pic.

I guess its missing?

 

[HB Chris]

Keep the felt on the edges at least, it keeps the plastic bits from rubbing and squeaking.

 

[Mark Jarman]

Erik -

Below is a picture of how my HVAC unit looked after re-gluing the fabric and replacing the felt. I was able to find felt that was like the old felt at my local fabric store.

Yes - both of the lower air vents that blow on your feet have a flap that is moved by the center control level on the HVAC controls. I think the flap is made out of plastic. I'm thinking you might be able to re-manufacture one either out of plastic or sheet metal.

Hope that helps.

 

[grnder95]

Hi Erik, my heater unit it's also missing one metal air vent, wonder if came like that from the factory.
Victor

 

[eriknetherlands]

Hi Mark, thanks for the tips.
I do have both flaps, but I seem to be missing one metal grille, a yellow cadmium plated metal part inside the opening. See

Anyone have one for sale?

 

[eriknetherlands]

Hi Erik, my heater unit it's also missing one metal air vent, wonder if came like that from the factory.
Victor

That could well be true. I think the parts books would give us the answer here.
I'll look it up.

 

[HB Chris]

Parts book says one only, ends in 042 which usually means right side but mine is on the driver side only.

 

[eriknetherlands]

Thanks Chris. So if only one was installed, then Im complete!

 

[HB Chris]

Kinda strange isn’t it?

 

[eriknetherlands]

Well, a drivers foot is quite near the opening, so perhaps it was mounted drivers side only, as they tried to spread the air a bit. That would be less an issue at the passenger side.

I do recall the sensation of having one half baked foot be it 7 years agoago. (Its bin that long, i have to hurry up..)

 

[ChrisandhisE9]

Hi Erik,

did you also open the heater box yet?

I'm in the process of restoring it, all the moving flaps inside have a foam rubber glued on them, I guess to prevent noises when operated. I'm still in doubt to replace it, or remove the remaining pieces.

 

[bavbob]

Hmm, my Euro has both grills, same age, seem original.

 

[eriknetherlands]

HI Chris, Yes, I also opened the heater box. For correct functioning you need some foam. The foam ensures closure of the flaps. If you don't apply the foam, air will leak into the other ducts. The ducts and flaps are designed to have a few mm's of foam between them. If there is no foam, the flap will rotate just a bit further, but this will not close the ducts.

I bought a square meter of EPDM closed cell foam, 5 mm thick. I only need 10% of it, but no other easily sourced option.

@ Bavbob, interesting that your cars has two of the foot vents / grilles. Parts books and other cars are now in favour of single grille, but ofcourse it could be retrofitted; just press one in and your done.

 

[bavbob]

Hagerty values show :
Subtract 20% for automatic
Add 15% for sunroof
Add 1% for two heater box grills