Two kinds of heater core

[BennyM]

Could someone please elaborate on the differences between the two heater cores? I know my car takes the newer style with a single group of aluminum pipes, but I don't know how much that changes the installation procedure.

Obviously, I would have to disconnect the heater valve connections on the other side of the firewall first. Do I have to drain the whole coolant system?
Also, since all of the DIY writeups show removal of plastic pipes (which I don't have), can I still do the job without removing the dash? Do the aluminum pipes unbolt from the heater core? According to RealOEM, it's all one awkward piece.

http://www.realoem.com/bmw/showparts.do?model=HD53&mospid=47404&btnr=64_0190&hg=64&fg=15

If anyone else has done this on their post 1990 E34, please enlighten me.

Thanks.
BennyM

[ryan roopnarine]

if you bypass the heater core first, you don't have to drain it nor worry about excessive coolant losses while you are performing your operation. furhtermore, if you bypass the core, and then bleed the system, you can drive your disassembled car around as much as you want whilst you change it out.

the pipe issue is trivial, simply remove two bolts, and it's out. instructions for either core are almost exactly the same, minus the removal of the pipes. totally intuitive.

[DueyT]

You have the new core. As Ryan said, it's connected to the feed/return pipes with two 8mm/T-20 bolts. I don't know about the 525i's cooling system, but I did my 540i's core a few weeks ago, and didn't empty the system at all, just had a few ounces dribble out of the first pipe I disconnected.

Yes, you will have to take part of the dash and the center console out to replace the core and the o-rings.

If you want, you can take a look at how I did mine here (http://forums.bimmerforums.com/forum/showpost.php?p=18317504&postcount=13). Yours should be very similar.

Overall, it took me about 8 hours to do the whole thing.

Cheers
Duey

[BennyM]

Duey, this is awesome. Those pictures of the pipes are exactly what I was looking for. Thanks, man.


You have the new core. As Ryan said, it's connected to the feed/return pipes with two 8mm/T-20 bolts. I don't know about the 525i's cooling system, but I did my 540i's core a few weeks ago, and didn't empty the system at all, just had a few ounces dribble out of the first pipe I disconnected.

Yes, you will have to take part of the dash and the center console out to replace the core and the o-rings.

If you want, you can take a look at how I did mine here (http://forums.bimmerforums.com/forum/showpost.php?p=18317504&postcount=13). Yours should be very similar.

Overall, it took me about 8 hours to do the whole thing.

Cheers
Duey

[DueyT]

Giddy-up! :D

Cheers