Reply With QuoteBump, question for those who've done the heater core replacement.
Big, Big Time Poster
'90 535i Heater core installation question
When installing the newer heater core with the 3 aluminum tubes already attached:
Once the console and heater control switchbox are removed or out of the way, would it be possible to install the heater core with 3 alu. tubes already attached? In other words, push the 3 tubes through their firewall grommet to mount the heater core.
This would be instead of installing the heater core, then trying to attach the 3 alu. tubes afterward, which by all accounts is a gross PITA.
From the RealOEM parts drawings, it looks like the 3 tubes pretty much go straight back from the heater core, penetrating the firewall perpendicularly. So, can you just install the HC+3 tubes as a unit?
Big, Big Time Poster
Bump, question for those who've done the heater core replacement.
3 Grand Master
the reattachment of the tubes to the core is only a PITA for people who have 1991 production year or later cars (i think its like 5/91 and after). this set up is like a $hitty duplex flarenut from hell to get back in. if you have the older, the tubes break apart in one or two places before the core. extrapolating from my investigation, the one fitting on my heater core that is the same as the three on yours is pretty easy to do back. if nobody else responds, the tubes will be the hardest part to do for you, routing them through and all. if you really want to replace them at the same time, just separate them from the core and run them through
Big, Big Time Poster
Thanks, Ryan. My new HC and attached 3 alu. tubes has not yet arrived from BMA, but from the RealOEM parts drawings, it looks like each alu. tube attaches to the HC at one end, then goes around the driver's side of the HC and straight back to the firewall penetration. If I knew how, I'd post here the RealOEM part drawing. Reportedly, my HC type is like the top or bottom one on RealOEM, where the plastic tubes are eliminated entirely. Fewer connections, O-rings, and plastic stuff that way.
So, since so many people have reported trouble with jiggling the 3 tubes into position with the clamps properly holding the O-rings, I am wondering why not leave the whole shebang intact with 3 tubes bolted on.
In this case, can the whole assembly be installed such that the 3 attached tubes go through the firewall grommet all at once? Or, are there too many obstructions between the HC position and the firewall grommet hole?
Big, Big Time Poster
good luck with that-- if I thought I could have done it that way, I would have. Getting those tubes to snake in the proper orientation, just getting them to the firewall is a huge PITA, then you've got to route them through the firewall. I can't imagine being able to do this without a great deal more disassembly, and by that point it might be easy enough to get proper leverage on the HC to get the pipes fitted.
I'd advise you not to install new pipes unless you are seriously worried about them being a fail point. Getting the two side pipes clamped in was a total PITA, but if I hadn't bothered installing the new pipes I could have been done nearly a day earlier.
It all fits so nicely when its out of the car....old and new. When the pipes and HC are in place, getting it to seat properly(especially with new new gaskets) is a magic trick I never really figured out.
PM me if you want any help or advice.
'94 540I 6spd/205000 miles
3 Grand Master
i don't understand your comment about eliminating the plastic tubes entirely.
http://www.realoem.com/bmw/showparts...74&hg=64&fg=15
do you mean this one?
what is the production date of your car?
Big, Big Time Poster
Just looking at that diagram gives me nightmares...Originally Posted by ryan roopnarine
'94 540I 6spd/205000 miles
Big, Big Time Poster
I did this a couple of months ago. I replaced the plastic pipes with new ones. I didn't find the job that hard. I had the heater core and the aluminum pipes removed and then reassembled it all in the car. I think it would have been much harder to assemble it out of the car and try to install the assembled unit in situ.
Big, Big Time Poster
Mine is a March 1990 535i. Per Patrick at BMA, it takes the other heater core shown on RealOEM, not the one you posted. The other one apparently has 3 aluminum tubes rather than the plastic tubes and extra O-ring fittings shown in your picture.
As I have neither received my new HC kit from BMA nor dis-assembled the console in the car for access, my mental picture is limited to impressions from various internet pictures, drawings, Bentley, etc.. With my luck, the car will reveal itself to have yet another configuration.
From what I've read here on bimmer.info and on Roadfly, coupled with pics posted and the Bentley, I gather that Bentley procedure seems the fastest and most efficient. One guy says he got this down to ~3.5 hours, yet others have taken a couple of days, including removal of the whole dashboard, steering wheel, etc..
Most of the reported trouble seems to arise from the difficulty of perfectly aligning the rigid alu. or plastic tubes to their O-ring fittings. Seems to me, some flexible coolant hose (of the sort used all over the place underhood) and some stainless hose clamps would do wonders with this application: You don't have to fight with flexible coolant hose for that last bit of positioning. Maybe cut the stock alu. tubes a few inches inside the firewall, remove and discard a ~10" section, to be replaced with coolant hose spliced in. Whatdya think?
3 Grand Master
it took under 6 hours, 2.1/4 to get in, 3.x to be careful getting out using roadfly. bentley doesn't tell you the position of every single screw, nut, procedure to finagle things out, but the roadfly one does. i would tell anyone not to bother with the other instructions on the web or bentley unless you want to remove more of your dash to get in and make other repairs. if patrick tells you that, and the etk says until 1/90, i guess i'm mistaken with how late that change took place.
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