Cooling system

[JGood]

I'm trying to figure out what goes where. This is what I gather, please correct me if I'm wrong:

-Water pump has 1 input and 1 output, both connect to radiator.
-Radiator also has extra nipple, which connects to reservoir.
-Reservoir connects to the rear coolant manifold/pipe.
-Rear manifold pipe comes with 4 nipples. 1 for the reservoir, another for the heater core? The other two can be eliminated?
-Lastly, the other heater core connection. Where does this connect to the cooling system? Surely it doesn't connect to the rear coolant manifold/pipe, or there would be no flow (without the aux water pump found in e32/e34).

[Garageaholic]

Justin have you checked the realoem diagrams?

[JGood]

Justin have you checked the realoem diagrams?

Yeah, they vaguely show how the system is hooked up, but the stock system uses an aux pump to circulate through the heater core, which I won't have.

[Jean]

Rear manifold connector piece/pipe on Manual cars has only 2 connections, fyi :) I'll try and get something drawn up...

What radiator you plan on using btw, z3m?

[JGood]

Rear manifold connector piece/pipe on Manual cars has only 2 connections, fyi :) I'll try and get something drawn up...

What radiator you plan on using btw, z3m?

Really? I looked at all the 530/540/740 variations on real OEM looking for a simpler pipe, I somehow missed that. Will check again, thanks!

I'm torn between Z3M and Mishimoto. They are both about the same price. I need to figure out the total capacity of each. What are you going to use?

[JGood]

Regarding the pipe, it looks like 9/98+ cars got the two-fitting pipes, regardless of transmission:

Part number: 11531437493




Unfortunately, the fittings are both facing toward the driver side, and I wanted my reservoir on the passenger side. And I'm not sure if it's tapped for the sensors? I'm guessing not, judging by your pic Jean:






Either way, I need to find out where the heater core will hook up to.

[g3n0cid3]

Another route is E38 coolant pumps have an extra port for an expansion tank. Also, they come with metal thermostat housing covers.

[JGood]

Ohhh, I like that! Ok, so water pump goes to both radiator outlets and expansion tank. Rear coolant pipe goes to heater core, all other nipples chopped/welded shut on that pipe. Where does the other heater core pipe go? Can I 'T' into the resevoir -> water pump line?

[Jean]

It will go to the other side where aux electric pump connects to, guys with v8 cars sometimes bypass it.

Keep in mind there are many different hoses too, some are specific to m62tu with water cooled alt so they have extra line for that....

[JGood]

It will go to the other side where aux electric pump connects to, guys with v8 cars sometimes bypass it.

Keep in mind there are many different hoses too, some are specific to m62tu with water cooled alt so they have extra line for that....

I'm not sure what you mean by that...

I got my engine in pieces, so I'm trying to mentally put this together from scratch.


Here's a diagram I made showing my confusion... Please correct me if I'm wrong here, and let me know where the '?' should connect to. Assuming m60b40 water pump, not the e38 pump discussed earlier.

[bmwmech1]

Okay goofy... look at the crossover manifold closely, specifically where the 2 tubes from the water pump go in. See how the smaller tube is segregated from the rest of the manifold? That keeps the heater core input and output separate, so the system continues to flow, instead of stagnate. If you are running heat, you need at minimum 2 outlets on the manifold, if your reservoir is also feeding into the manifold, you'll need 3. E38/39 setups are different, since the reservoir is at the front of the engine bay, the water pump has the 3rd nipple/inlet. I used an E38 manifold, so I only had to close off 2 nipples and then move 1 to the passenger side. I also drilled and tapped the bosses for the 2 temp sensors, which is easy to do. Any more ???, just LMK...:)

Garey

[JGood]

That answers everything, thanks. I didn't look at the manifold closely, I assumed it was all one big open passage. I'll refrain from asking more questions until I start putting the engine back together :)

[bmwmech1]

That answers everything, thanks. I didn't look at the manifold closely, I assumed it was all one big open passage. I'll refrain from asking more questions until I start putting the engine back together :)

Lol... I'm just messin' with you... I knew by your confusion, exactly what you hadn't noticed on the manifold... No big deal

Garey

[marshallnoise]

I realize this is a necro-bump, but someone, somewhere will find this thread and the info in it useful (as I did). I am updating it with my schematic of the manifold and how it flows.

[MonkeyMadness]

I realize this is a necro-bump, but someone, somewhere will find this thread and the info in it useful (as I did). I am updating it with my schematic of the manifold and how it flows.

Better late than never I guess..~!