Replacing the E30 Heater Core and Valve

[xcx4x]

Thanks a lot JinormusJ! The link you provided will definitely help. I just ordered the new O-rings.

As for coolant, is there a specific place I add the coolant? It sounds like a dumb question but its just that since my heater core has been bypassed, does it mean that when I un-bypass my heater core, coolant from the reservoir will automatically go through the heater core? Where did it go before? I'm just having a hard time picturing the IN and OUT of the "system".

[JinormusJ]

Replacing the E30 Heater Core and Valve

Questions:
1. After changing heater core, assuming everything else is ok, what else do I need to do?
2. After changing heater core, do i just fill up new coolant and go from there? What else should I consider for my heat (and therefore my AC) to work? I am assuming that I won't have to do anything related to the AC coolant right? That stuff is in its own system, and me changing the heater core has nothing to do with R-22 right?

3. See photo. Boxed in GREEN, are those the pipes that everyone says I should be changing? Seems kinda pricey at $34 a pop...=(

4. See photo. Boxed in RED, I'm assuming this was the hose that used to be connected to the pipes?

5. So it looks like the previous owner just disconnected these hoses/pipes to bypass heater core? Are there any implications for doing this? I've been driving it DD for past 3 months without any issue but...

1. What else do you need to do in regards to what?

2. Yes; as a note, the cooling (heater) system has nothing to do with the AC system: they are two separately run systems (heater uses engine ports/hoses/coolant, AC uses compressor/hardlines/freon)

3. Those hardlines are okay to keep unless they are warped or pitted. Mine were pitted horribly, so I replaced mine, but you can get away with not changing them. Also, $34 is not a lot to spend on needed maintenance ;)

4. Those are the block hose and spider hose, and yes, they are the hoses used to route the heater core. Spider goes up top, block down low

5. Mine were bypassed by my PO for years. The only thing that it affects is not having a heater


EDIT:
Might help you along with the write-up in the OP

http://www.r3vlimited.com/board/showpost.php?p=3524990

[xcx4x]

Hey Everyone,

So I bought my e30 with the AC not working because the heater core is not working. This is all the information I have.

I recently acquired a used heater core and plan to change. After going through this entire thread, I have some questions....

Questions:
1. After changing heater core, assuming everything else is ok, what else do I need to do?
2. After changing heater core, do i just fill up new coolant and go from there? What else should I consider for my heat (and therefore my AC) to work? I am assuming that I won't have to do anything related to the AC coolant right? That stuff is in its own system, and me changing the heater core has nothing to do with R-22 right?

3. See photo. Boxed in GREEN, are those the pipes that everyone says I should be changing? Seems kinda pricey at $34 a pop...=(

4. See photo. Boxed in RED, I'm assuming this was the hose that used to be connected to the pipes?

5. So it looks like the previous owner just disconnected these hoses/pipes to bypass heater core? Are there any implications for doing this? I've been driving it DD for past 3 months without any issue but...


Thank you all for your time and help!!!

[cunninglinguist]

There is one for sale on Amazon.com if you search with the BMW part number.

[anthonymax007]

how much is that water valve?

I think the valve for the aluminum inlets (part number 64111386707) is discontinued. Looks like I might have to find a used one.

If you have the plastic inlets the part number is 64111386706, costs $216 on Pelican Parts.

[iPee]

how much is that water valve?

[///M42 sport]

anyone find that the water valve was leaking on theirs? Thats another pricey part I just found out.

[Liquidity]

I had no idea this was that easy. Here I am driving around with no heat because I didn't want to pull my dash off.

[Shimmwagen]

I picked up a 35$ heater core off eBay, not behr obviously but fit fine and heat is good. Old behr had crack in plastic on passenger side. Got o rings and coolant from pelican.

[torreira]

i have a heater core available if anyone needs

[fronton]

if there was coolant in the heater box id imagine your heater core is toast. you could try blowing into one of the pipes and blocking the other one, while spraying down the heater core with some dishwashing soap mixed with water in a spray bottle, and youll likely see the bubbles if there is a pinhole somewhere. the leak below the trans could be from the two bolt little coolant outlet pipe that bolts to the back of the head. when you tried to bleed it did you feel both heater hoses? if one was hot and one was cold either there was a blockage in the heater core, the heater control valve wasnt opening, or there is a coolant circulation problem

Thanks, I tried testing the core with soapy water and blowing into one end with the other blocked but still no detectable leak. I wasn't able to feel the firewall inlet and outlet hoses because the plenum is in the way. I didn't see a leak from that back coolant outlet pipe on the head but its pretty much against the firewall so hard to see much back there.

UPDATE It was indeed a bad heater core. I replaced it with a new OEM core and there is no more leak and coolant temp holds at the half mark at idle. For those who are still running the original core, replace it before it dies, they are only $150 and can save you from a really inconvenient situation. Not only that but you'll be surprised at how much crap is gunked up in it.

[atldohc]

if there was coolant in the heater box id imagine your heater core is toast. you could try blowing into one of the pipes and blocking the other one, while spraying down the heater core with some dishwashing soap mixed with water in a spray bottle, and youll likely see the bubbles if there is a pinhole somewhere. the leak below the trans could be from the two bolt little coolant outlet pipe that bolts to the back of the head. when you tried to bleed it did you feel both heater hoses? if one was hot and one was cold either there was a blockage in the heater core, the heater control valve wasnt opening, or there is a coolant circulation problem

[fronton]

Any one have thoughts on what else could cause a coolant drip from the transmission besides heater core? I have a new one on order along with water pump just for piece of mind. Any coolant seals or gaskets on the cylinder head that could be replaced?

[fronton]

After flushing the coolant from this winter's storage, no heat through the vents. I didn't drive around but was revving the engine to 3k a fair bit to warm the engine and when the water temp gauge got to 3/4 so I shut it off. With water that hot, the tstat must have been open but perhaps air was trapped in the heater core. I repeated twice trying to confirm no air in the system. After an hour of the bleeding game, I noticed a slow coolant leak dripping off of the transmission crossmember. I dried up the coolant, opened the coolant cap and quit for the day to allow for bleeding over night without a pressurized system.

Next day, the same puddle has appeared under the transmission, probably a couple fluid ounces. There shouldn't have been any pressure forcing it to leak with the cap off. No damp carpet and I couldn't trace the leak to the engine so assumed it to come from the heater core figuring the coolant was dripping from the core into the heater box and then into the tranny tunnel, onto the transmissions, then crossmember.

I drained the coolant, pulled the heater core and there was a little coolant in the heater box. I also confirmed the heater valve and tstat to be working properly.

This seems like a straight forward bad heater core issue but two things bother me.

1. I can't get the core to leak by just filling with water and letting it sit. I realize that a hairline crack may only leak under extreme pressure which I can't recreate at a kitchen sink but it leaked over night, without any pressure in the system.

2. Can water really get from the heater box through the transmission tunnel? I couldn't pull the heater box to see if there is drain hole but if there isn't my problem can't be the heater core.

3. With as slow of a leak that developed, the heater still should have blown warmer than ice cold, unless air was trapped somewhere not allowing proper bleeding.

Any ideas one why I can't get the core to leak? Is there a hole in the heater box and the trans tunnel to even allow my theory? Where else could a leak be from off the trans crossmember if not the heater core?

My system is the late model one with metal pipes.

[Ceeker]

I've done the heater core a thought it was not too bad. Have to do the evaporator so wanted to see what I was getting into. Thanks!

make sure you evacuate the system before attempting..believe me you don't want that in your face.