Author Topic: Fan Delete Mod (Read 17567 times)

victor.askew · « **Reply #30 on:** December 05, 2011, 09:35:29 PM »

I removed the factory clutch fan and installed a 1850cfm aftermarket fan last wkend. I am using the same relay and fuse protected circuit as the factory elect fan did. As for the temp fan sensor its brand new but I have not pluggrd it in yet as I want to see what type of temps would be maintained by using the thermostst to control the engine coolant temps with this fan on always. So far I have a very stable mid point guage reading, never going past midpoint and 90/95% of the time just ever so slightly to the left side of the midpoint mark. Im happy with this.

DesktopDave · « **Reply #31 on:** December 05, 2011, 10:17:18 PM »

I've never heard of a low coolant warning sensor. There isn't a sender for it on the car and I'm not sure how we'd engineer something like that. I'm pretty sure all our e30 M42's were never intended to have a low oil or windshield washer fluid indicator like the M20's check control did...they took all that out for the M42.

The radiator fanstat switch is also in a very good place, on the hot side of the radiator it will react to changes fairly quickly. Most BMWs have it in the exact same spot. It does control the aux fan in front of the rad. I'd advise testing it...if I recall correctly:
1. Turn the key to position 1
2. Make a short length of 14-ish gauge wire into a jumper by stripping both ends
3. Pull the plug off the switch and short the black/red wire socket to the green ground socket. The fan should turn on low speed.
4. Pull the jumper out of the black/red and put it into the black socket. The fan should spin at high speed.

The two coolant temp sensors on the side of the head are in the best position IMHO. They sit high on the head, so if you develop a bubble or the thermostat fails closed you'll see the temp sensor move quickly. The cluster sender might have been bad, and even if it is good, the gauge is designed to sit in the middle most of the time. It's "buffered" so that it looks kosher when in fact it might be ready to pop the gasket. The gauge is scaled so that it tends to stay in the middle...I've heard some BMW guys figured that the middle mark by itself was about a 20 degF range.

The fuel gauge is the same way, at least in US cars. 3/4 tank to 1/4 tank is nearly all of the gauge sweep, so psychologically most people feel that it gets better mileage.

In fact, BMW made two production changes on the e30. You'd figure they'd make the gauge more accurate, right? Maybe enable the high temp warning light? Nope. They put a bypass in the heater hoses to prevent overpressure from rupturing the heater core (not fun, I've had it happen to me on my old VW). Then they found the profile gasket failure and replaced a bunch of engines. They didn't fix the worst problems though...the plastic pump impellers, the cheap radiators or the too-thin head casting.

cristimm · « **Reply #32 on:** December 06, 2011, 04:07:18 AM »

Quote from: DesktopDave;108613

I thought it was a replacement for the stock sensor in the side of the radiator, right?

I'd figure that it cuts the fan on a bit earlier to compensate for the clutch fan.

Exactly. I recommend the lower temp switch for any bmw fan delete or not.

spanish_pants · « **Reply #33 on:** December 06, 2011, 12:57:15 PM »

The low coolant sensor is something that came on the e34. There is a little float screwed to the bottom of the coolant resevoir.

bbarnumboy · « **Reply #34 on:** December 06, 2011, 07:25:32 PM »

Got the parts.

Just completed the install of the new fan switch and fan relocation as well as the clutched manual fan delete.

Well now that i got the bugs worked out, it is working flawlessly. I love it. This is by far the easiest modification i have ever done. I now have tons of room for my large heat exchanger in the front bumper.

I do not know why, but after i installed everything, i could not get the fan to switch on by itself. I checked all fuses and they were good.

I ended up jumping the cable to test the fan and both hi and low worked great. I then took the old fan switch and put a lighter to the sensor part to heat it up. It worked automatically on both hi and low. Realized my coolant was a little low, so i filled it up and plugged the new switch in, and viola. She works perfect.

So one thing i have learned is. Even though the coolant is not dangerously low enough to make the car overheat itself, the high positioning of the switch on the radiator can cause it to not get reading, if your coolant is slightly low. This is a little unfortunate.

Thanks for the great idea! and for those that want to know. the part numbers listed a few posts back are the correct part numbers, so order away.

(This was on a 1993 E36 318is with AC)

bbarnumboy · « **Reply #35 on:** December 08, 2011, 08:06:07 AM »

For those who are still on the fence about this, i would like to confirm on last thing.

This new fan setup performed flawlessly, while sitting in stopped traffic for 1 hour yesterday. No signs of it trying to get hot.

victor.askew · « **Reply #36 on:** December 08, 2011, 11:25:14 PM »

A cool M42 is a happy M42. I learned this the hard way!!!!!!

otwohr · « **Reply #37 on:** June 01, 2013, 12:00:20 PM »

I've been reading through the various fan delete mod postings and am considering doing this on my '91 E30 318i, similar to those done by cristimm and deekay a few years back.

I'm sick of hearing the howling clutch fan and my goal is to replace it with an electric one from the E36 318 (p/n: 64508372039) plugged into the cars' a/c fan harness, along with the 80/88 degree temp switch (p/n: 61318361787). From what I've read, this seems to be the hot setup ....actually I guess it's the cool setup!

What I haven't been able to find is if anyone has done this and is still running a/c, and if this single electric fan will provide sufficient engine and a/c condenser cooling. Most folks indicate that they've ripped the a/c out of the car but I'm keeping mine and want to be sure the fan mod will work. Sorry if this has already been addressed but I couldn't find any posts about it.

Thanks