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07-14-2020LAST POST
Thanks to edsonreds on this thread and everyone who has posted advice and videos for this challenging DIY.

Non-obvious advice I didn't learn from other posts:

1. If cost is not your number one priority then get AC system degassed at a shop first.
2. Video yourself OR take photos of every non obvious step AND bag all fasteners with respective parts together AND put labels on the electrical connectors so you won't have to rely on memory/fit.
3. The only wiring parts I broke were (2) white wiring harness clips. Order a few of these ahead of time (photo attached from ebay). It is also a good idea to get a roll of Tesa wiring harness tape for small repairs as you go.
4. The only dash clips I broke were these unusual spiral things attached to the cross member and the left knee foam protector 2 x (51457130934). They take a week to come to the USA from Germany.
5. There are two bolts that need to be accessed from the engine bay. One is from the evap/matrix box and it is (a torx) in the middle of the firewall/bulkhead about 12cm (4") down from the top. It is behind circular plug 11 on http://www.realoem.com/bmw/enUS/showparts?id=VA93-USA-03-2008-E90-BMW-M3&diagId=51_5865. The second is from the cross member behind the steering column and it comes out behind some brake lines to the right (from front of car) of the coolant and AC lines through the fire wall.
6. I recommend removing as much as you need to in the engine bay to make accessing coolant and AC lines easier (air filter, plenum, etc.). Buy hose removal pliers ($15 from harbor freight) https://www.harborfreight.com/3-piece-long-reach-hose-grip-pliers-37909.html?_br_psugg_q=hose+pliers
7. The engine bay work on this job is the most challenging part. The interior work is a memory test and a test of skill in not breaking clips/connectors.
8. Honorable mention to the 2 speaker connectors in the back center of the dash board. You need to set the dash in place then lift it and reach back in and up towards the windshield. A maneuver that almost put my back out.
9. If you do not have the phone option there will be two unused connectors on the center console wiring loom.

Good luck and enjoy not paying the $3300 I was quoted at a Bay Area dealer. That will pay for a lot of $1 clips!!

p.s. A few days later while adjusting my steering wheel back to straight ahead I broke the clock spiral. It is part of the control stalk assembly so it is very expensive. You can find it used by searching for bmw 698955702 to get the OEM part (part of the larger assembly). I paid $45 on Ebay.
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edsonreds wrote
Hi. Yeap. I've seem videos among them the one you posted. I gathered the TIS instructions. So far removing the dash doesnt seem scary. I am figuring out how to make the A/C system drawn off. I am concerned because the Manual says if the system is open more than 24hrs I should change the dissecant. I think I will research more. My evaporator will come in a couple of weeks. Luckily I found a way to know whether I needed a Valeo or Denso evaporator without dismantling the dash.
Hi! I have a leaky evap and I was wondering how you found which your car has before disassembling the dash, steering wheel, plenum, etc. Is it possible to lookup by VIN? Maybe manufacturer will match the compressor? Maybe I will buy both so I have each option available when I disassemble everything in the coming month.

Also, in another thread you stated you might share the ISTA service manual as the TIS was lacking information regarding a few other 🔩 bolts for the dashboard's support strut. Would it be possible if you could send it to me?
aerospacey wrote
Hi! I have a leaky evap and I was wondering how you found which your car has before disassembling the dash, steering wheel, plenum, etc. Is it possible to lookup by VIN? Maybe manufacturer will match the compressor? Maybe I will buy both so I have each option available when I disassemble everything in the coming month.\
My car had a white BMW stamped label attached to the wiring harness that connected to the rear of the climate control interface (dash buttons) that made reference to my car having a Valeo evap unit. Your's may have a similar label.
Theodore wrote
My car had a white BMW stamped label attached to the wiring harness that connected to the rear of the climate control interface (dash buttons) that made reference to my car having a Valeo evap unit. Your's may have a similar label.
Thanks Theodore! Just getting around to this now since my headliner caved (about $275 to fix locally) due to the lovely Charleston humidity and having the windows down last week to go pick up a new amplifier.

I'll order the valeo replacement now, but the Hella brand, Behr brand, Rein brand, and Nissens brand replacements for Valeo are looking pretty good vs the more expensive Valeo and Genuine BMW prices especially since they screwed this design up so bad
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I don't have much hvac experience...is there anything else that needs to be replaced when replacing the evaporator? aI'm guessing the o-rings/gaskets and the expansion valve. Am I missing anything else that is critical?
You probably have already seen this, but in case you haven't this guy goes step by step and provides amazing detail and answers your question :bow:

https://www.m3post.com/forums/showthread.php?t=1723803
aerospacey wrote
I don't have much hvac experience...is there anything else that needs to be replaced when replacing the evaporator? aI'm guessing the o-rings/gaskets and the expansion valve. Am I missing anything else that is critical?
ohhhh that would have been nice before I started it today! thanks anyways! I got down to the steering column to crash bar external torx bolts, stuck until I get some e-torx sockets now. 😕
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For others planning on undertaking this r&r - order a new sticky back foam gasket set (Denso 64116950976 / Valeo 64112453899) or buy some 1/2" wide sticky back foam to replace your seals on the ac/heaterbox...mine were garbage...
Thread referenced by br2wdc in AC doesn't work. Any ideas? 08-13-2020