Spal electric fan conversion (fan clutch delete)

[bmw540san]

Let me start by saying that this is IMO and I've had this upgrade perform flawlessly on both of my E39's for well over a year now. Some may disagree with some aspects of this upgrade but 2 things are clear:

1. fan clutch is sort of obsolete system by now and while it performs fairly well on BMW engines, it does create potential issue by literally disintegrating and creating quite a bit of damage. There are different opinions on why but the fact is that it does happen on V8.

2. While DME controlled thermostat does have some advantages it is set to 105 C + which is simply to close to dangerous temps. BMW did this in order to decrease emissions and improve fuel economy but one thing is clear: More heat = more pressure which puts stress on plastic cooling components.

Also, these are original 11 year old parts with 96k miles on them, so it's not like I'm trashing brand new parts. Another thing I like about the this upgrade is the extra room in engine compartment.

So here we go: (items in the first picture)

High performance ultra quiet Spal fan

195F Spal sensor with wiring and relay:

Sensor will be placed in Auto Meter radiator hose adapter right after the lower radiator hose OEM coolant sensor. The sensor will activate the Spal fan if the coolant coming out of radiator is 195 F (90 C) and the fan will stop when the coolant cools down to 175 F (80 C). As I said, having this on both E39's, the Spal fan will come on at certain situations but never more than 30 sec.

Upper radiator hose for non Vanos M62 engine:

This hose will be connected to M62 95 C conventional thermostat (not pictured) which will replace the original OEM DME controlled 105 C thermostat. 95 C thermostat is direct fit to the WP opening. The disconnected DME wiring will have proper resistor in order to keep DME from throwing a code.
It's worth mentioning that 95 C thermostat is found on early 1996-97 840ci and in my 540 is keeping the temp around 95-97 C which is hot enough to properly burn all contaminants in combustion chamber and yet there is extra 10 C of buffer compared to OEM 105 C.

24" x 24" 0.080 6061 aluminum sheet:

As in both of my e39's, I prefer to keep OEM shroud which I modify to receive aluminum plate with the cutout for Spal fan. This way, the OEM look is retained and everything is sealed in order for Spal fan to properly pull heat from radiator (sort of vacuum function)




Contens of 195F Spal relay kit: Everything is high quality and it was very easy to wire the system on my E39's






Fitting the 195 F Spal sensor into Auto Meter radiator hose adapter. I've used this Permatex sealant on E39's and it's designed for coolant purposes and it doesn't interfere with the ground function of adapter body.




Continued here:

http://www.xoutpost.com/bmw-sav-foru...-part-2-a.html

[admranger]

Are you keeping your aux fan?

[romeokc10]

Let us know how it turns out, I'm sure you've read the thread below.

http://www.xoutpost.com/bmw-sav-foru...-electric.html

[g300d]

With our trucks having electronic thermostats that regulate coolant temps, won't the DME attempt to get temps up via the thermostat if you hook up that fan without somehow addressing the temp regulating function?

[bmw540san]

Originally Posted by admranger

Are you keeping your aux fan?

Yes. This replaces fan clutch.

[bmw540san]

Originally Posted by g300d

With our trucks having electronic thermostats that regulate coolant temps, won't the DME attempt to get temps up via the thermostat if you hook up that fan without somehow addressing the temp regulating function?

You've probably missed it in my post. DME controlled thermostat is being replaced (just as in my 540) with the 95 C conventional thermostat without the DME electrical connector (as found in early 840ci with M62 engine).

This thermostat is direct fit to WP opening other than having old style hose type fitting which is easily remedied.

DME wiring will have proper resistor which has been proven to keep it from throwing check engine light or the code.

[g300d]

Oh, my bad, I missed it in your original post.

Looks well thought out so far, please do post results. I'd be interested to see actual coolant temps and oil temps after you do this.

[g300d]

Oh, and no plans to do the lower pressure coolant cap?

[bmw540san]

Originally Posted by g300d

Oh, and no plans to do the lower pressure coolant cap?

To answer both of your questions:

The coolant temp will go down for about 8 C to 10 C which is not much but it's enough to give me extra piece of mind. My other concern with DME thermostat is horror story of actual coolant leaking through seal around the connector and ending up in DME itself. It's very rare and no I'm not kidding:
Timm's BMW M62TUB V8 Engines - Engine Failsafe

I don't want temps to drop down to much as that creates its own set of problems. The oil temp probably won't change much and that's not my goal anyway. I won't mess with cap pressure.

[g300d]

^thanks for answering, looks like an interesting approach to lower operating temps.

Looking forward to updates!