Engine Fan Delete

[NC325iC]

matt, i dont understand what you mean

as far as wiring it up, i have the aux fan switch on the pass side of the rad with the single 3 wire connector. i turned the car to on checked all 3 wires for voltage, one of them had voltage remebered whichn this is. turned the ac on (fan turns on low) since the fan is on the corresponding wire now has 12 as well, splice those two wires together keep the plug on the power source, plug the sourcewire back in where it was plug the 3rd wire into where the low speed wire was, tada

[Jand3rson]

so you guys that are putting in the e46 switch, what is the point of this? If i remove the fan clutch assembly altogether and leave the front electric fan in place, would this fan turn on if the car heats up? or only if i turn on the a/c? confused***

It's the E36 switch, and it makes it so the electric fan turns on sooner than it normally would, eliminating the need for the larger, engine driven fan.

[matt]

What I meant by my comment is that the stock water temp gauge cannot be trusted. Delete your fan and your motor WILL run hotter, but the gauge will still be in the center.

[e30_325es]

Matt- can you prove this?

[Jand3rson]

What I meant by my comment is that the stock water temp gauge cannot be trusted. Delete your fan and your motor WILL run hotter, but the gauge will still be in the center.

Not with the different fan control switch. It will turn your electric fan on sooner, and the electric fan moves more air than the engine driven fan.

[matt]

Matt- can you prove this?

Ask anybody with an aftermarket water temp gauge. The stock one is in the middle from 170 to over 220 degrees. It's nothing but an idiot light.

A friend with an e36 has a datalogger in his car that has a low mass thermocouple in his upper radiator hose. He'll see 220 with spikes to 250 without the stock gauge moving one degree from center. Our cars are probably not that bad, but running 10 or 20 degrees hotter isnt good.

Eurospeed, if you think the electric fan moves more air than the mechanical one, you are crazy. Get your car hot and rev it up with the hood open standing by the engine bay, then connect an electric fan to some current and see how it blows. No comparison.

[Jean]

I just recently removed AC from my car and ordered brackets to mount the AC fan as a secondary fan infront of the radiator, I am going to try and connect it and see if it works :)

[Jand3rson]

Eurospeed, if you think the electric fan moves more air than the mechanical one, you are crazy. Get your car hot and rev it up with the hood open standing by the engine bay, then connect an electric fan to some current and see how it blows. No comparison.

My point is that the electric fan moves more than enough air through the radiator to provide adequate cooling for the engine, I just worded it wrong. The mechanical engine-driven fan is not needed. Besides, the amount of air moving through the fan while sitting in my driveway revving the engine isn't the same as the amount of air that's moving through the fan and radiator while doing 60 down the highway.

[Jean]

So I got the brackets from the dealer the other day but looks like I need more parts to actually mount them in place to the top of the radiator support ? I see holes there but can't use a bolt/nut in there ... how do you guys mount them ??

[jlevie]

Sticking an oar in late in this discussion...

As many people know, BMW engines are not at all tolerant of high temperatures. Failure of the head gasket has been known to happen after a single overheat. That being the case the safe approach is to have more cooling rather than less. The OE system with the engine driven fan is pretty bullet-proof if kept in good condition. But if you delete the engine driven fan you'd be well advised to replace it with an electrically driven fan puller (of 1600CFM or more) operated by an 80-84C thermoswitch.

Best case, if you delete the A/C, is to have both a puller fan that comes on at 80-84C and have the existing aux fan come on at low speed at 91C and high speed at 99C. That will require some creative rewiring of the aux fan circuit since it is normally enabled by the A/C switch. It also means that you have to have a radiator with two thermoswitch ports. I don't know of any three way thermoswitches.
Here's my situation. I have a chipped M20b27, and I'm removing the entire AC system this winter. The climate here in the summer is hot (extremes being high 90's-low 100's), and it's VERY dry, very little hunidity. My car's cooling system is phenomenal, even in the extreme summer temps, my needle rarely, if ever gets anywhere near the mid-way mark, never even close. My plan is just to run the electric fan with the E36 318i fanswitch, and possibly at some point, swap the stock aux fan out for a higher performance FAL.

[ddavidv]

Did you figure out those brackets yet? They are a little confusing. You have to 'rob' the speed nuts from other locations (condenser?) so the bolts have something to thread into. The bottom mount to me didn't really fit right. I think I had to shim it with some washers or something.

As far as the a/c fan alone being inadequate...not so. Every Spec E30 racer I know runs with just the a/c pusher fan. The only danger is having to remember (unless you rewire it) to turn the a/c button on and shift one of the sliding levers over to activate it when you are needing it. I have a big FAN ON? sticker on my instrument cluster to remind me. But, I really haven't needed it much even after several hard laps on the track.

[matt]

Did you figure out those brackets yet? They are a little confusing. You have to 'rob' the speed nuts from other locations (condenser?) so the bolts have something to thread into. The bottom mount to me didn't really fit right. I think I had to shim it with some washers or something.

As far as the a/c fan alone being inadequate...not so. Every Spec E30 racer I know runs with just the a/c pusher fan. The only danger is having to remember (unless you rewire it) to turn the a/c button on and shift one of the sliding levers over to activate it when you are needing it. I have a big FAN ON? sticker on my instrument cluster to remind me. But, I really haven't needed it much even after several hard laps on the track.

I know spec e30 races have a lot of traffic, but Im guessing you don't get totally stuck all the time. COmmute in Atlanta without the engine driven fan... I wouldn't.

[nando]

Did you figure out those brackets yet? They are a little confusing. You have to 'rob' the speed nuts from other locations (condenser?) so the bolts have something to thread into. The bottom mount to me didn't really fit right. I think I had to shim it with some washers or something.

As far as the a/c fan alone being inadequate...not so. Every Spec E30 racer I know runs with just the a/c pusher fan. The only danger is having to remember (unless you rewire it) to turn the a/c button on and shift one of the sliding levers over to activate it when you are needing it. I have a big FAN ON? sticker on my instrument cluster to remind me. But, I really haven't needed it much even after several hard laps on the track.

huh? you don't need to turn on the a/c switch for the fan to operate. ALL YOU NEED IS THE E36 M42 TEMP SWITCH. that is it. it will come on regardless of what the A/C is doing.

as far as the temp gauge, matt you are confused. you are thinking of later BMW temp gauges, which do not move despite temperature fluctuations. no, the E30 one isn't "accurate" since there are no #s, but it works just fine - it will move plenty with temperature fluctuations.

besides that, most M20s will stay between 1/4 and 1/2 without any fan at all. I think my aux fan has only come on twice now since I removed my clutch fan... it runs pretty constantly between 1/4 and 1/2.

[Jand3rson]

Chris, is it better just to go ahead and buy one (E36 temp switch) new, or can I just get a used one from Funk or something?

[Dave]

Chris, is it better just to go ahead and buy one (E36 temp switch) new, or can I just get a used one from Funk or something?

Josh, they are not that expensive. Think I paid like 18-20 bucks at the dealer with CCA discount.