installation order - heater / ac

rsporsche

rsporsche

Moderator
Site Donor $$
Messages
13,763
Reaction score
6,204
Location
Atlanta, GA
okay guys - its about time to start installing the heater + air conditioner. since i didn't take them out, i'm a little lost on order of install, and since my track record shows that i take 1 step forward / 2 steps back. and get to practice / remove + reinstall things a couple of times.

any advice would be appreciated
 
Scott,
the heater box goes in first and is sitting at the firewall.
The AC evaporator box goes in second and sits in front of the heather box.

The AC box sits on a base plate bolted to the transmission tunnel.
The two systems, once in placem need to be connected via the infamous intermediate piece.
Before you put in the intermediate piece and the heather front/air outlet, remember to put the probe from the temp switch into the target location into the evaporator.

You have some nice pictorials here:
eriknetherlands

Thread 'DIY - Heater unit rebuild'

My pay back to the forum; here's my approach to rebuilding the heater box from my E9. Not sure how this compares to e3, but let me know and I can possibly merge.

I'll likely chop it in roughly three pieces; removal, disassembly, repair and rebuild. I haven't installed it yet myself, so i can't do any pics of that :) .
I will add sections in the coming days, depending on how boring my meetings in the office will be....

Cost & time estimation: About 450 euro and 30 hours.

- Re-cored heat exchanger: 231 euro
- Re-zinced parts (done with other parts, so I just take a part of it: ) 30 euro's...
  • Like
  • Love
and here:
Bmachine

Thread 'Re-installing the AC evaporator'

Part 1: Preparation:

Here are the parts you will need:

AC evaporator e9.jpg
Throughly clean the air box and reinstall fresh felt around all of its leading edges to ensure good air sealing. I got rid of the foam pad which had deteriorated and did not seem to do that much anyway.
I later added a few strips of dynamat to tone down the vibrations

412AEC13-3FA2-48C7-A20E-C9CFB5544E1F.jpeg

C49470F3-5AFC-42A5-ADEE-366975568815.jpeg BF618313-59BD-49CF-8A65-CA8B04F236F0.jpeg

Disassemble the Evaporator to clean it up, removing all rotting foam and accumulated dust

AC1ECCC9-F080-4425-A5A9-6C33A6194F36.jpeg

At this point I would highly recommend getting @Blinkling ‘s upgraded evaporator guts. It’s...
  • Like
Luis A.

Post in thread 'a/c drain not draining'

This rubber funnel only shows up on the E3/12/24/21 and 28. It perfectly seals and funnels that area to gather the condensate. Notice the nice cut-out in the front to allow the plastic drain protrusion of the AC box to slide over it and into its center. Still available as of 3 years ago. Also a foam cylinder interfacing between it and the tunnel sheetmetal. Although photos are from E3, all work well on the E9...

Heater box:
1779254964916.png


AC base plate:
1779255082859.png


good luck with the install - a job that requires patience and persistence!
 
I drilled a small hole in bottom right corner for the probe and could feel it go into the fins. It will fall out in my experience.
 
  • Like
Reactions: Dlc
Scott - in this post you can see where the evaporator, intermediate piece and heater box sit:
BMW3.0CSi

Post in thread 'BMW 2800cs -> S38b36 project'

Progressing further, installed the interior heater housing and evaporator housing to see how the AC lines match up which are from an old AC installation and will be used as a reference only before installing new ones.

Was a bit surprised by the fact that the intermediate part on top of the evaporator housing was so much ‘blocked’ by the edge of the evaporator housing as you can see in the pictures. Should be normal I guess? And I still need to re upholster the edges of the intermediate part.
  • Like
 
so here's an interesting question - insulation. there is a foam sealing ring around the opening for fresh air. have people found it better to stick it onto the body or onto the heater itself? i was thinking it would be best to stick it onto the body so you don't damage it trying to get the heater mounted onto the studs.

next question, realoem shows 2 pieces of insulation around the heater pipes at the firewall. one is L shaped and the other is rectangular. then there is a racetrack oval shaped piece under the metal cover in the engine compartment. both 9 + 10 have the same part number on realoem ... the orange book shows 2 separate pieces. but here's the weird part - there are 3 #10s in the orange book where realoem shows 1 - perhaps it was a thickness thing. so i imagine i will install the bigger L shaped piece and cut the other piece down to a rectangle ... using the leftover piece to make the oval insulation on the other side of the firewall.

make sense? any thoughts?

1781721412921.png

t
 
I think part of the answer depends on what you are using for your firewall insulation. I think I used the one from Alprado, which is fairly thick (see photo) and included just an oval-shaped cutout, so I just put a small piece of foam and the metal oval plate. There is no way I could have fit that many layers into the narrow space. If you had a thinner firewall material then you could potentially fit some more thickness in there, I imagine mainly just to insulate the area of most heat exposure.
 

Attachments

  • IMG_9424.png
    IMG_9424.png
    485.7 KB · Views: 8
i think what happens here is - the insulation around the pipes (inside the engine compartment) goes on top of the firewall insulation / under the metal cover - this is the racetrack shape .... it is held tight around the pipes by the heater hoses pushing the metal cover as tight as possible into the firewall. the L shaped and rectangular go inside the car around the pipes (between the firewall and the heater). this helps for heat soak around the drivers feet.
 
  • Like
Reactions: Dlc
here is a quick update on the initial question - adhesive side up / adhesive side on the heater? i started with it up and the adhesive didn't really keep it there. after it fell while putting the heater into place, i put it on top of the heater ... and i got it on, but i still have to loosen up the heater and push the insulation back into place. i will tell you, getting the heater into place to get the washers / nuts into place ... PITA. i found that having a couple of blocks of wood on top of the tranny tunnel to wedge the heater into place while trying to get the nuts into place. keeping the washers in place while trying to install the nuts is tedious as there isn't a lot of room to manipulate tools / fingers.
 
rsporsche said:
i think what happens here is - the insulation around the pipes (inside the engine compartment) goes on top of the firewall insulation / under the metal cover - this is the racetrack shape .... it is held tight around the pipes by the heater hoses pushing the metal cover as tight as possible into the firewall. the L shaped and rectangular go inside the car around the pipes (between the firewall and the heater). this helps for heat soak around the drivers feet.
Click to expand...
Confirmed on all points Scott.
The round small piece goes on the firewall in the engine bay and is held in place by the metal cover and the pipes.
The L-piece sits on the heather box and goes towards the firewall from the inside.
The rectangular frame sits on the upper frame that goes into the upper body cavity with the 4 studs.
And yes, this is PITA work....

Are you considering installing a heater-bypass valve while you're in there?
I put one in as per the recommendation on the forum, which can be controlled by a switch and is a simple open/close type.
 
Last edited:
You must log in or register to reply here.
Back
Top