I think I f'd up... (cooling system help needed)

[JGood]

I'm having much difficulty bleeding my coolant system. As in, I've spent over 5 hours dumping water in, watching it boil out and overflow, and repeating. Everything is new, water pump, thermostat, hoses, radiator, reservoir, block/heads were flushed, etc...

I think I found my problem this morning. I had my coolant manifold modified, so the normal reservoir outlet (far right in the below pic) was blocked off and welded shut. The far left outlet was then hooked up to my reservoir. However, I noticed that port is actually directly connected to the smaller coolant pipe that runs up the the front of the engine, into the water pump. The "normal" reservoir outlet is on a different "circuit", as you can see in the pic.

So what I think is going on, is I'm feeding water into the "out" side of the water pump, so it's just pushing the water back into the reservoir and not taking any new water, and not pushing the air out of the system.

Thoughts?

[dirty30]

The small downward facing coolant nipple on the drivers side of the crossover pipe should be the heater core inlet in your application. I think you are forcing coolant into your reservoir the way you have the heater core hoses set up. Think of it this way:

The small pipe that runs in the valley is the feed so it is recovering coolant from the heater core and the reservoir. The large pipe has pressure from the water pump, it feeds the cylinder left and right banks and the heater core. You should have the small drivers side outlet that originally fed the trans cooler hooked up to the heater core inlet and the other off of that "Y" being used as the return from the heater core. I'll post a picture of mine but I had Gary set it up totally different.



The large port coming out of the top of the driver side goes to the bottom heater core inlet on the firewall. The drivers side facing port on the "Y" goes to the top port on the firewall. The other side of that "Y" is my inlet from the expansion tank.

Here's another pic I think I stole from Jonsku that helped me a lot:



Hope this helps!

[JGood]

So what you are saying is, I have it hooked up correctly? I didn't actually verify my input/output on the heater core yet, I just drew that picture under the assumption that that small pipe was pressure from the pump. The heater core lines are easily switchable, I'm not too worried about that. My only concern at this point is to verify coolant is flowing from the reservoir into the system properly. And from your description, and Jonsku's pic, I have it set up properly.

Something has to be wrong, it simply will not bleed at all. I can't imagine (potentially) having the heater core lines hooked up incorrectly would cause this? Or am I wrong? After 5 hours of filling and bleeding, I'd think all the air would find it's way to the highest point and escape. Both heater core pipes on the interior are hot when the engine is running and I turn the heater on.

[dirty30]

If you have the heater core lines hooked up like the picture you posted they are backwards.

[JGood]

OK, but I'm not concerned at all with the heater core at this time. I have no idea how they are hooked up, I'll have to check when I get home. My only concern is that the reservoir is feeding the system properly. Unless having the heater core lines reversed could cause the system to not bleed, in which case that could potentially be the problem.

[JGood]

I just found a pic I took when I was installing the heater core lines. The drivers side facing port on the "Y" goes to the top port on the firewall, which is how you and Jonsku have yours set up. So everything is hooked up correctly.

The only other thing I can think to check at this point is that my thermostat is functioning (I'm assuming it is, since I'm getting hot water into the radiator?), and that I did not leave the towels that I jammed into the water pump holes to keep debris out, in there when I connected the hoses.

[JGood]

Interestingly, it appears that Garey has his set up the opposite of you and I. He has his reservoir connected to the main pipe, not that separate Y pipe. You can see where he welded the nipple on, up at the far end of the passenger side, past the sensors.

[JGood]

The heater core hoses were backwards. I flipped them, and spent the past 2 hours trying to bleed the system. It's doing the same fucking thing is was before.

I'm really sick of this. Any advice is greatly appreciated.

[JGood]

Got it bled. My buddy stopped by, blew into the upper rad hose towards the water pump, which pushed the air bubble out, and then we filled the system via the upper rad hose. Reconnected it, and started the car. No more overflowing or overheating.

Well, it did overheat after a while. My 14" pep boys special isn't a good enough fan to cool this monster (big surprise). Time to get a good fan.

[bmwguy325is]

Got it bled. My buddy stopped by, blew into the upper rad hose towards the water pump, which pushed the air bubble out, and then we filled the system via the upper rad hose.....

I always do better after a good blow. Glad you figure this out.

[JGood]

Oh yeah, there were plenty of blowing jokes immediately afterwords. haha

[JGood]

Well, scratch that. Took it out for some 50mph+ driving, still overheated.

My current thoughts:

I'm using a 95 C thermostat, and I verified via boiling water on my stove that the thermostat opens up about 1/4" at about 95 C / 203 F (is that all the further it opens?). My coolant expansion tank cap is 1.4 bar, stock m60 is 2.0 bar. Is it not building enough pressure to prevent boiling? Either way, the temp would be the same, and that temp is in the red zone on my gauge.

I've yet to do a coolant CO2 test. I'm going to see if I can find a tester tomorrow. I'll also pressure test the coolant system.

[Jean]

It's fixed yes?

[JGood]

Yep, my electric fan was spinning the wrong way, causing the car to overheat, there was no air in the system at all. Yellow wire = ground, black wire = positive, contrary to the directions, and common sense. The curved blades push air in weird directions when spinning backwards, it's not entirely obvious when it's spinning.

Now, on to the other problems...

[Jonsku]

Well, it did overheat after a while. My 14" pep boys special isn't a good enough fan to cool this monster (big surprise). Time to get a good fan.

Is the radiator up to the job?

My coolant expansion tank cap is 1.4 bar, stock m60 is 2.0 bar.

Swap it to 2 bar item, otherwise it'll just keep throwing coolant off the system when it heats up properly. These engines like to run hot, and they WILL run hot in the E30 'bay.


This might clarify coolant flow in M6x;