[zigsman]

Okay, here is a comprehensive DIY for replacing the heater core on an E90. Mine does not have the iDrive, so, if you do, there will be a few additional and different steps. Hopefully you can work around it. If you need a larger photo (better quality), PM or email me with the task number and photo description, I'll get it sent over as soon as I can. If you get stuck somewhere along the way or have a question, feel free to PM or email me. Good luck!!

Mike
zigsman@aol.com

[335i101]

Originally Posted by zigsman

The file is 15.1mb so I am unable to post it here. Send me a message with an email and I'll send it to you. If you know of somewhere I am able to post a file this size, please let me know and I will do so!

Mike

Thank you for doing this!!!

[rtgirard]

Zigs, I bow before your superior testicular fortitude. I would not want to attempt that myself and I'm super-happy that my core replacement was done under warranty.

[zigsman]

Originally Posted by rtgirard

Zigs, I bow before your superior testicular fortitude. I would not want to attempt that myself and I'm super-happy that my core replacement was done under warranty.

It's not something I want to do again, but I would to save 2k! And I could probably do it in half the time next time around...God forbid!

[duaux]

OMG.

Zigsman...
Thank you for contributing to the community.

[txusa03]

Great job and thanks for the contribution. At the end of the day, not having to fork over 2K to a stranger ripping up your car is a win win situation for me. I am with you on that one.

[Cram979's335D]

Dude !! you ARE the Man !!

[tarux]

Hey,

Why did you this step ? :
"3231070 Remove lower section of steering spindle"

I can't see why ?

[zigsman]

Originally Posted by tarux

Hey,

Why did you this step ? :
"3231070 Remove lower section of steering spindle"

I can't see why ?

You must remove the steering wheel in order to remove the dash from the vehicle. You disconnect the steering linkage in that photo (in the engine compartment) and pull the entire steering column out of the car from the driver seat.

[tarux]

thank's for the replay,

but I don't see in this video the man doing this, maybe can we skip this step ? :

[zigsman]

Originally Posted by tarux

thank's for the replay,

but I don't see in this video the man doing this, maybe can we skip this step ? :

That video plays REALLY fast! I can tell for sure whether or not he disconnects the steering linkage. If there's a way around it and it saves you work, by all means, go with it. I followed the instructions in the TIS service manual which required the disconnection of the linkage to pull the steering column. There may be a shortcut, I don't know.

[tarux]

Indeed the video play very fast, but the hood it not "up" position during hole video (lol), anyway thank's very mush for the DIY, will use it a lot

the lower linkage linkage of the steering column is only one bolt ?

[zigsman]

Originally Posted by tarux

Indeed the video play very fast, but the hood it not "up" position during hole video (lol), anyway thank's very mush for the DIY, will use it a lot

the lower linkage linkage of the steering column is only one bolt ?

Yes. You only need to remove one reverse torx screw and then pull the linkage apart. It may be a bit difficult, you may need to wiggle it a bit.

[BeastMode335i]

Thanks for this zigsman , I know it's been a little while but this detailed DIY will definitely assist me this weekend..!

[Walletsr]

What needs to be done to discharge the ac?

[siphor1989]

Originally Posted by Walletsr

What needs to be done to discharge the ac?

Bring it to a shop that has r134a machine and they'll be able to evacuate the ac system for you.

[zigsman]

Originally Posted by siphor1989

Bring it to a shop that has r134a machine and they'll be able to evacuate the ac system for you.

Yes...what he said! That is the proper and safe way to get it done. You could hook a set of gauges up to the car and crack the low side valve open, but that would let all the R134a escape into the environment. That is not good, and probably not legal in most places.

[Nando_e90]

Hello guys!

Found this thread and maybe you can give me an opinion about my similar issue. My e90 330i flows hot air drivers side and cold air on passengers. I think it could be the heater core but when reading codes with INPA I got following errors:

"9C48 mixed air flap left"
"9C4C footwell flap"
"9C4E striation flap"

Looks like it has three stepper motors bad, but a friend in other forum said that its difficult for three of them to go bad at the same time, and it could be a connection/electrical issue. Just for the records, previous owner did something to the a/c system but don't know what exactly, but dashboard was removed some time ago because there were two bolts missing inside. So whoever who did the job may have connected something wrong.

I hope you can give me your opinion about it.

[zigsman]

Originally Posted by Cala

Hello guys!

Found this thread and maybe you can give me an opinion about my similar issue. My e90 330i flows hot air drivers side and cold air on passengers. I think it could be the heater core but when reading codes with INPA I got following errors:

"9C48 mixed air flap left"
"9C4C footwell flap"
"9C4E striation flap"

Looks like it has three stepper motors bad, but a friend in other forum said that its difficult for three of them to go bad at the same time, and it could be a connection/electrical issue. Just for the records, previous owner did something to the a/c system but don't know what exactly, but dashboard was removed some time ago because there were two bolts missing inside. So whoever who did the job may have connected something wrong.

I hope you can give me your opinion about it.

If you have diagnostic software, like Bavarian Technic, or ISTA, you can manually activate each door individually to see if they are operational. You should be able to hear them open and close. If you don't hear it, then either the door is jammed or the motor is not operating. If all the doors operate properly, then I would pin it down to a plugged heater core. I would most definately troubleshoot the doors/actuators before pulling the dash out of the car.

[Nando_e90]

Originally Posted by zigsman

If you have diagnostic software, like Bavarian Technic, or ISTA, you can manually activate each door individually to see if they are operational. You should be able to hear them open and close. If you don't hear it, then either the door is jammed or the motor is not operating. If all the doors operate properly, then I would pin it down to a plugged heater core. I would most definately troubleshoot the doors/actuators before pulling the dash out of the car.

Thanks for the reply! I will try to install ISTA in order to do that. It would be great to know if blend doors are working with the software. Also read in an article that there is an specific order for the stepper motors connections, so maybe they are connected in the wrong way. I will try to verify that also.

[larrygas]

Hi,
so I went through the process to replace my heater core and took the dash out... (Although i left the HVAC box in and did not have to drain or disconnect the AC.)
But my problem is that my new one (Valeo style) does not fit all the way in. It looks like some plastic tabs inside the HVAC box are blocking it from going in on the last 2 inches. So frustrating. I thought it might be the wrong part but everything i see online says this is the right one, and pics look like the one i got. But you can see there is a slight offset with the hoses position - and the issue seems to be the ridge where the metal parts of the casing are clamped together; it sticks out at a different height and hits the plastic tabs (or one of them).
Note: the old one *looks* kind of like the Denso models, but the HVAC clearly says Valeo.
The old heater core says : "Denso C2116140-0242 VALEO 985422U 13.10.06"
The new one is a ACM Germany 64 11 9 128 953

Anybody seen this problem before?
I feel like breaking those plastic tabs off... if i can reach in there...

[larrygas]

Well i'm an idiot.
After reading on-line, checking 5 times, i still managed to order the wrong heater core. i happen to have the DENSO.

I still don't get it because the HVAC sticker behind the radio says Valeo and the core was confusing to me since it has both denso & valeo numbers - none of which seem to cross-reference correctly, so i went off the sticker.

The bottom line is that the valeo i have here just wont go all the way in and I noticed the tube sizes are wrong anyway; the I have 0.75" diameter ports and not 0.8125" like the valeo setup (I got these numbers from rockauto info pics).

I just ordered another core...
What a mess.