Viscous Fan Removal

[trottsky 24]

Had a quick look and couldn't see anything that had been discussed before (I am a bit retarded though so there might well be). But anyway, I was just wondering if anyone has ever just removed their viscous fan and had any overheating issues? I know the proper way to do it is to fit a lower temp thermostat, temp sensor and beefier electric fan etc.

I've worked on loads of cars where the fan clutch isn't even doing anything anymore as it's so old and never locks up, most don't seem to have any issues at the time (not sure if any damage is being done due to slightly higher temps in the long run though). Anyway I've got an m52b28, I've got a/c so it's got an auxiliary fan which works and was just pondering the idea!

[yng_750 247]

Have done it. Didnt lower thermostat though.

Fitted16" electric fan and adjustable thermostatic switch set to around 92 on the outlet from.memory.

No issue so far 6 months later. E36 323

[antil33t 90]

I did that, i've had it for two years and no issues, E34 M50.

Except I used the factory fan model thermoswitch which comes on at 80 degrees.

[euroriffic 600]

I'd just replace the vicious clutch or fit a replacement electric one. An m52 is basicly scrap once overheated

[jonesrp 63]

i`ve just had maintenance done on my cooling system by the good lads at Victoria Street Motors. My viscous coupling fan failed the rolled up newspaper test so they replaced it, along with the water pump and thermostat. Heater is now unreal, I can`t let it run at over 18 degrees.Car makes a nice woofing noise on start up which I guess means the the fan wasn`t working too well previously. As Justin says the M52 doesn`t like to overheat. The viscous fan is there for a reason so I couldn`t imagine getting rid of it.The fan coupling itself cost $260 bucks .Whole maintenance job slightly more.

Gotta watch the cooling system in an e39. Why risk ruining the car ??

[trottsky 24]

Hey guys cheers for the input! Yeh I know you shouldn't really mess with things that are obviously there for a reason, but at the same time I can't see any reason that it is there for other than to draw air through the rad while the engine is at idle in traffic. So whenever you're moving it's pretty much redundant in my theory? So if you were to lower the temp at which the electric fan cuts in, surely that would be doing the exact same job as what the viscous fan does without the parasitic drag? I might try it and see how it goes seen as it's winter and cold as f*ck anyway : D

[twisted 45]

My car ran about 10 degrees cooler at idle when I replaced the fan clutch. Tbh, the parasitic drag is sfa, as once moving the car cools down enough to switch off the fan in a matter off seconds.

Deleting it could open you up to a whole lot of m52 cooling system pain. If that motor gets hot, then prepare to replace everything that is plastic or has a rubber seal.

[Allanw 1051]

Also, the electrickery to run the electric fan comes from the batetry, and the battery is charged from the alternator... which is a parasitic drag... Plus the fan is only really a drag when it's locked.

PS - the newspaper test ONLY works if the viscous coupling is hot enough to cause the clutch in it to lock - which isn't that much of the time TBH (the V8's seems to do it more than 6's)

[MoJoJoe 46]

I have had a old(bad) and new fan clutch before, the old one if something you can easily turn and spin the blade but on the new (good) one you can not. just something to watch out for, other then that removing it is pretty easy, just a locking tool to the waterpump (A big screw driver also works) then a 32mm wrench and a good hammer blow and you are done.

go to milland, look him up on trademe, the fan clutch can be had for around $150 shipped. a good german oem like brand.

Edited June 20, 2014 by Dr. Jekyll

[thorburn 120]

Don't do it. I ran a lower temp thermostat, brand new water pump, radiator, hoses and BMW coolant. I'd removed the fan thinking it'd be ok. While waiting inline for the skid pad at Hampton downs the temp started going north.

Also there was no noticeable gain in performance.

[yng_750 247]

If it over heated sitting still obviously your fan wasnt functioning

[thorburn 120]

You might've missed the part where it says the fan was removed. It had run perfectly fine with the same part for 2 months before hand.

Op learn from my mistake and at least run an electric fan.

[yng_750 247]

I was refering to the electric fan it was replaced with. you did replace the viscous fan?

[thorburn 120]

there's the problem. No fan. I was another sucker that believed what was said in US forums.

[KwS 2373]

IIRC the idea of removing the viscous fan was that the AC fan in front of the radiator would come on and be used to cool the radiator. From what i remember when i looked into it the fan comes on as an "emergency backup" when the engine exceeds a certain temp (IE if the viscous fails, the idea is that the ac fan will still operate and hopefully stop the overheating), hence the need for a lower temp fan switch to turn it on sooner.

The problem i see is that the AC fan isnt designed to be used as a main fan, and cant shift anywhere near as much air as the viscous fan can, and this leaves no overhead or backup in the event of a hot day, hard use or long periods of no airflow.

Just fix the viscous fan, or if you really hate it that much fit a replacement electric fan in its place.

[yng_750 247]

Yea no the ac fan wont come close to enough flow. Just compare the light hum it makes to the roar of a good 16".

Might work in canada

[kiwi328i 118]

I did the fan delete mod, just google it, it's been done many times before. My M52 328i ran sweet as, no problems for 2 years before I sold it. I think it was a new lower thermostat and temperature switch, viscous and fan off and done.

[Michael. 2312]

I don't like the fans for the drag the put on the electrical system, putting more mechanical load on the alternator to turn.

A good viscous system is the way to go.

Or Toyota/Lexus with their hydraulic solenoid controlled fans, better again

[yng_750 247]

Putting mechanical load on the engine to avoid mechanical load on the alternator?

[Michael. 2312]

Yep. More efficient so I've read.

Quieter too. Electric fans are noisy bloody thinks. My hydrofan in the E36 with the 1UZ was nearly silent.

"The hydraulic drive can draw more power from the engine than an electric fan, and thus move more air through the radiator for more effective cooling. And compared to a directly-driven unit, the hydro fan’s speed isn’t dependent on engine speed—the solenoid that controls the flow of hydraulic fluid through the fan motor can opt to run the fan on high speed as the engine idles, for example, or completely freewheel the fan on the highway"

Edited June 25, 2014 by Michael.

[yng_750 247]

I like hydraulic fans. on racecar or high performance car i would go electric just so i can leave it running with engine off to stop engine bay temps spiking.