Cooling system combo's

[rs4pro3]

What combo of parts is everyone running for there cooling systems? I'm trying to figure why I had so much trouble with the system on my m30.
I was running e28 535i 5-speed radiator, pre 82 M30 water pump(dosn't have fan clutch threads), 88 325i coolant resivor, mixture of e28 and E28 coolant hoses.
And a 3600 cfm electric fan in front of the radiator to keep it cool.

[E30/M30]

E34 M30b35 engine and water pump
E30 325 header tank(a mate of mine with a 335 is using an E34/2 header)
New E28 535 rad
E28 535 bottom rad hose
E34 535 top rad hose
Single electric fan from a Peugeot 205 (1.1L or 1.4L ???)
The fan is switched on by the ECU via a relay,the switching point is some thing like 96c or 98c ???

At motor way speeds(60-100mph) it sits just above the 1/4 mark
20-40mph(ish) it sits just under 1/2 way
under 20mph the fan cuts in and it never gets any higher than about 1/2 way

I was expecting the fan not to cope with the Summer temps but it's ok,it just come's on a lot if your stuck in slow moving traffic.

I'm guessing your average temp in the US might be more than over here in the UK ?





HTH

Andy

[rs4pro3]

thanks, let's keep the info cumming. There is rumur also that the fan clutch and fan from an early 324td fits. It's about a $150 combo here at the dealership so I may check it out when the M30 goes back in.

[uflnuceng]

I don't have an electric fan yet.

Im using an E28 535i automatic radiator and the stock E30 325i overflow tank in stock position. I bypassed the heater core.

The engine doesn't overheat during normal running, but if I leave it idle after running it hard it definitely starts to creap up in temperature. I wouldn't dare take it through stop and go traffic without installing an electric fan but I have no idea which one I should go for. I'll flip through the summit racing catalog I guess.

[george graves]

all stock m30b35 parts except a heater core line or two. a good fan that really pulls - urrr, I mean pushes. (radaitor is COLD to the touch sometimes)

[uflnuceng]

George:

What fan are you running... how is it hooked up? Got pics? Part numbers? Is it hooked to t-stat or just always on?

[george graves]

Someday I'll get around to hooking up a t-stat to it. Right now it's running on the AC fan wireing. I run it full time. But I can turn it on and off with the AC switch if need be (really cold morning to help it warm up)

I forget the mak of the fan - it's got straight blades - I *think* the curved blade designs are quiter.

[uflnuceng]

That's pretty darn trick. When I cut the AC fan out, there are like 9 wires in there. Which ones did you hook up. Gimme details! :D

[george graves]

Hmmm - I think mine had 3 wires. We (M3 Ryan and I) I think used a multi-meter to find the correct wires.

Have some one sit in the car turning on and off the AC button, and search for the corect ones.

[rs4pro3]

Assuming you wiring is still intact for the AC system, There are 2 ways to hook it up.
You can either have it run on Low speed when you press the AC switch and when the sensor on the radiator hits 99C the fan kick in on high speed. Or you can wire it to run always on low or high.
If you want option one...........
At the stock AUX fan plug there are 2 wires, Red, Black, and Brown
Brown is ground
Black is 12 volts from the Low speed relay that goes threw the Low speed fan resistor(attached to the side of the stock fan) and then sends 5-6 volts or so to the fan.
Red is full 12 volts that is sent to the fan once the radiator hits 99C
When you press the AC button voltage should come threw the Black wire, if you remove the resistor then your fan will run at full speed, with having the black and brown wires hooked up.
On my car I custom built a complete harness, mimicing the stock system with 2 relays the switch on the radiator and then I eventualy added a switch so I could change it from Low to High Speed.