tom__w

So I have a C4S side by side with a TT. The TT heats up nicely with 140+ coming out of the vents. When checking the hoses going to the exchanger, they are about 135 on the inlet and 115 on the outlet. I am measuring with a laser thermal temperature sensor.

The C4S has roughly the same temps on the hoses but I have about 110 coming out of the vents.

Is this conclusive that the problem is the blend door foam? Is there another way to confirm / diagnose this problem?

I tried covering the air inlet below the cabin filter but I didn't see an appreciable difference. In fact, when I covered it I got so little air through the vents that it was hard to tell.

I'm thinking I might attempt this repair today if I can get some feedback...

s65e90

Pull the heater core and you can partially see inside and feel the blend door and see if the foam is gone. Most likely it is. I had this issue and when I moved back to NY the heat was very marginal out of the vents. I was able to repair the blend door without doing any damage (as most cut the pivot/door to remove and fix). Start by removing the clip on the passenger side for the blend door actuator. Then remove the cowl vent and heater core. With the pivot/actuator arm removed you can now swing the door with your fingers back and forth. There's little to no room to work, but if you're very careful and steady you can use HVAC tape as it's stiff and place pieces along the door to cover the holes. I did this a while back and the heat has returned and gets super hot.

I used the HVAC tape as it's good for the job and being stiff allows you to cut pieces and hold them rigid as you will have to slid them through a channel only slightly wider than the tape. You can move the door a tad with you fingers back and forth as you do this. It's tricky as the sticky side will get caught alot on the thin passage but it's doable without having to cut anything on the car to fix outside.

tom__w

So you just used tape without removing the door itself?

Might be a challenge as I have xl hands.

s65e90

Yes, I've only seen people remove it before, but that means hacking apart the cars heater system as it's sealed. You can do it through the top using better HVAC tape (metal for sealing vents). A little more frustration but it's the right way to do it IMO as you don't damage the car. At least remove the heater core and look at it. It's easy enough to get to for inspection.

tom__w

Working the project right now.

I got no foam!! Lol

tom__w

Almost done. Just need to put everything back together.

the only reason I could apply tape without using a dremel was because I had NO foam left. Had there been foam, I would of had to remove the door and clean it.

it's about a 2.5 to 3 hour job. Maybe a little more if I had to remove the door.

And yes, that tape sticks to everything when trying to fit it in...

Carlo_Carrera

Nice work.

s65e90

Nice You know the door goes into that void and theres more holes in there.

tom__w

I slid the tape past the pivot point and got both sides. Wasn't easy but got it done.

garrett376

So is the door a "V" shape with foam on both outer sides of the V?

tom__w

yup

T Kono

Isn't there an additional blend door for the outside/inside air mix? It too is subject to the disintegrating foam problem but is only accessible by removing the dash, etc.