E30 Heater Control Valve Repair!

[barbierij]

Hey everybody. The '89iX had a nasty leak coming from the heater control valve. We fixed this about 4 months ago and its about time I put it up as a fix. Plus someone on the rev forum was looking to buy one. Good luck dude, even if you had $400 this thing was discontinued for some reason. Originally, I thought I would just put a manual valve under the hood and turn the heat on in the winter. But, like most E30 owners, we are do it yourself. Here we go:

We start with the super hard to find a replacement for stupid valve:



Then, we want to drill the el-cheapo copper rivets out. maybe they are brass. Either way, they are stupid. I only drilled the top part of the rivet off because the bit for my dremel was larger than the inside diameter of the rivet.



We want to clean these parts. I used the degreaser found at harbor freight... the $8 gallon one. Brake cleaner is better probably, because the harbor freight stuff takes a long time to get off. It might just be my crazy mind, but I think my fingers start tingling when I have them exposed to the harbor freight stuff.



I rebuilt this thing, and put it in the car. It still leaked. i took it apart again and realized this crack. Solder it. you a plumber? awesome. if not, you might have some trouble. I had my iron at 850 degrees and it took about 20 minutes to get the solder to sink into the crack. I had to blob it up.













Make sure you grind the solder down flush to the copper. Atleast flush where the gasket seats.



Make sure the solder flowed to the other side. You can add solder on this side too, but again make sure its flush atleast where the gasket seats.



<a href="http://s321.photobucket.com/user/barbierij/media/325ix%20heater%20valve%20repair/12_zpsc3830f1c.jpg.html" target="_blank"><img src="http://i321.photobucket.com/albums/nn394/barbierij/325ix%20heater%20valve%20repair/12_zpsc3830f1c.jpg" border="0" alt=" photo 12_zpsc3830f1c.jpg"/></a>

Now we put it back together. I dont remember what size I used. They were leftover from a megasquirt build. They are metric and the same size as whatever a TO-220 insulator kit comes with. Just longer.



All done!




happy picture!

[N3nyongmini]

Great write up bro.

[barbierij]

Thanks dude!

[bavarianbrawler]

Good write-up. Was there anything to replace in terms of gaskets or o-rings within the valve itself, or does the failure occur with the copper piece you soldered?

[Nihilator]

Is there any reason to think a good epoxy wouldn't work here?

Is there any way to test the electrical portion of the valve to verify that it's functioning correctly, and is there anything you can do (lube, clean contacts, etc.) to keep that portion of it from failing prematurely?

--Chris

[barbierij]

UPDATE: Still works and no leaks!

- - - Updated - - -

And I didn't replace the gasket. I might have replaced o-rings on the pipes if they were shot and if I did, I used harbor freight o-rings.

[So Live]

UPDATE: Still works and no leaks!

- - - Updated - - -

And I didn't replace the gasket. I might have replaced o-rings on the pipes if they were shot and if I did, I used harbor freight o-rings.

Might want to try soldering with a torch of some sort. Blobbing solder on both sides doesn't make it a reasonable solution even though it is I definitely better than the leaky alternative (apparently).

[bavarianbrawler]

Is there any reason to think a good epoxy wouldn't work here?

Chris - to answer your question, epoxy seems to work. I used JB Weld and my valve is now working beautifully.

[Bremith]

Hi I may be a bit simple but how do I test this is working? Mine clicks and everything and the little thing with the cone of rubber moves in and out, but it makes no difference to flow of water - I attached to a garden hose and water flows straight through regardless of whether the valve is "on" or "off" and/or which end of the pipe I attach the hose.

am I missing something? Shouldn't turning the valve on/off (ie connecting it to 12 v) stop and start the flow of water?

any assistance appreciated!

[barbierij]

It developed a super slight leak. I haven't taken it apart yet, and probably wont until I replace it.

[joce30lover]

just got a coolant leak on driver's side, worked on this and solved the problem, excellent post

[bbkhine]

Appreciated if you can advise me on which hoses that the heater valve be connected to, either to the hose coming from the back of the head or the hose coming in from coolant reservoir. Both heater valve and heater core hoses are all metal in my 1990 BMW 325i. Those hoses were bypassed by previous owner and I just replaced them with a new heater valve and heater core. Thank you in advance.

[richardodn]

Hose from the back of the head goes to the inlet on the heater core. The inlet pipe is the one with the valve.

[bbkhine]

heater-valve-connection.jpg

Hose from the back of the head goes to the inlet on the heater core. The inlet pipe is the one with the valve.

Hi, excuse my ignorance. I am totally new to this build but I am trying :-) following you guys board. Should this pipe with valve be connected to the hose coming from the back of the block?? or the bottom pipe that is connected directly to heater core??

[superj]

the half black pipe is the one that goes to the hose that connects to the back of the head

[bbkhine]

Finally my heater is working! Thank you guys! "The hose from the block goes the bottom aluminum pipe (in) that is connected to core. The spider hose from the reservoir goes to the top aluminum pipe with the valve attached (out)"

[Woz4niak]

I wanted to thank you for this writeup. I had a leak in my heater valve, which ended up being caused by two of the four rivets failing allowing the valve enclosure to open up and leak. Prior to finding this thread, I was resigned to replacing the valve, which is a close to $300 part. Your write up gave me the knowledge and motivation to try the repair. Worked out great, and my valve is now bolted together instead of riveted and no longer leaking. I found that in reinstalling the valve, it helped to withdraw the heater core about an inch, in order to get the pipes properly seated and the valve back into its original position. Not a fun job overall, due to the amount of trim removal required, and the contortions required to remove and replace the valve, but working patiently and carefully, very doable.

Thanks again for the excellent writeup!

Tim