Heater core valve?

[a32guy]

What is the correct functionality of this thing? I get no flow through the heatercore when attempting to blow on the lower port, but when I blow on the upper port, I do get flow from the upper to lower port. Condition is the same regardless of key/temp position.

I've been battling cooling issues non stop on this swap. Any help is appreciated.

Ps- Please excuse my crosspost, trying to get the most info before tomorrow when I work on this thing.

[matt]

Can we have a little more than "battling cooling issues?"

Are you overheating? No heat in the cabin?

I have never seen an e30 heater valve fail unless it just starts dumping coolant on the carpet.

Which way are you hooking up the lines? They only go one way (as you can see).

[a32guy]

Can we have a little more than "battling cooling issues?"

Are you overheating? No heat in the cabin?

I have never seen an e30 heater valve fail unless it just starts dumping coolant on the carpet.

Which way are you hooking up the lines? They only go one way (as you can see).

Yes, the car overheats and there is no heat in the cabin. It is an M50 with M42 radiator in an 89 325i. I originally had the spider hose going to the upper port, and the back of the head connected to the lower port. I had no heat with this method so I swapped them. I didn't seem to get heat for a while, then the car started overheating-- on my way back home the temps were getting pretty warm and then I strangely started getting heat. I didn't want to run the car anymore at this point since it was overheating.

My plan for the morning is to:
1. jack the front end very high
2. use my airlift ii tool to vacuum and refill the system
3. run the car with the cap off, bleeder open, and aux fan on high
4. hopefully purge any air locks and have a working cooling system!

If this fails, I will check the water pump, check flow through the radiator, swap heater core hoses back, and gut my heater valve (if need be).

Thoughts?

[a32guy]

So I think I figured out whats going on. I checked the flow through the rad and checked the water pump-- all was normal. I filled the system and let it idle up on stands. I got heat, but the car started overheating. On closer inspection it appeared my m42 coolant bottle was leaking from somewhere. I topped it up, and bled the air out the upper hose by leaving a gap at the top. Once water overflowed from it, I slipped the hose back on.

The car started maintaining temp for a while with the aux fan. Heat was coming out pretty good. Finally it started overheating again-- I would attribute this from the bottle leaking again, and not enough water able to be pumped through the rad.

I guess its time to buy a new radiator? :(

[matt]

Yeah coolant cools better when it's in the motor.

Can't you just replace the bottle like an e36? I dunno, never seen an M42 radiator.

[a32guy]

Its weird, it looks like it should come out but half of it is built into the radiator. Hard to describe, you'd have to see it.

[a32guy]

Okay so I got my new radiator today. This helped a ton, but something still isn't right. On stands idling, the car wouldn't get above 11 oclock on the temp gauge with the a/c fan on-- sweet its fixed I thought!

I take it out on the road, all was fine for about 10 minutes and then the gauge slowly started creeping up. Didn't matter load/road speed/fan on or off.

It got to about 1 oclock on the gauge when I got home. Upper hose was damn hot, lower hose was cool. Does this mean there is still air in the system? I thought I had it all bled, especially since it was fine idling for nearly a half hour with the front up on stands.

Thanks in advance, any advice is appreciated!

Chris

[BenM]

I would add more coolant via the top hose and try rebleeding. Sounds like there is still air in the system.

Sorry I can't add more, everything else sounds good!

[matt]

Did you test for flow through the new radiator? Did you have heat?

I agree that another attempt at bleeding is in order.

[a32guy]

I didn't test for flow through the 'new' (used but clean) rad... probably should have. I did have very hot heat.

Thanks guys, will try rebleeding in the AM.

[atldohc]

Okay so I got my new radiator today. This helped a ton, but something still isn't right. On stands idling, the car wouldn't get above 11 oclock on the temp gauge with the a/c fan on-- sweet its fixed I thought!

I take it out on the road, all was fine for about 10 minutes and then the gauge slowly started creeping up. Didn't matter load/road speed/fan on or off.

It got to about 1 oclock on the gauge when I got home. Upper hose was damn hot, lower hose was cool. Does this mean there is still air in the system? I thought I had it all bled, especially since it was fine idling for nearly a half hour with the front up on stands.

Thanks in advance, any advice is appreciated!

Chris

if one hose is hot and the other is cool then your thermostat may be stuck closed/not opening enough