M20 Viscous Fan Questions

[M3KUK]

Hi, the fan on my 320i Cab was 'whooshing' as if it was faulty, ie on all the time. I swapped it for my 325i fan and it went away.
I examined the old 320i fan and it was quite stiff to turn, as you would expect. I have just bought a brand new fan viscous unit and instead of spinning freely, it too is stiff to turn?

I have fitted it and it is quite whooshy still, what the hell is going on? I thought it would be free to turn when cold and when hot become harder to turn thus turning the fan without any slip?

Thanks for any advice!

[JungleGus]

You can't really tell when off the car - old school method is getting a newspaper in there once the the engine is up running and hot...if the newspaper stops the fan it's knackered.

They are often iffy but a new BMW or good aftermarket brand tends to fix the issue...is the car overheating at standstill?

Wooshes and other noises at standstill are normal! It's when they stop it's the issue...

[biffer]

should expect some resistance to turning even when cold.

[M3KUK]

It's not overheating, just the whooshing noise was annoying with it being a convertible! With the saloon you don't notice it as much. I will try the newspaper trick later today.

[Brianmoooore]

New viscous will often behave a bit like an old seized one for a week or two, until the bearing frees up.

[M3KUK]

That's exactly what it's doing Brian, whooshing from cold. I'll leave it on for a bit then and see.
Gus you owe me a copy of The Guardian!

[paultv]

I had exactly the same issue, after market cheap-ish unit, never freed up - sounds crazy at tick over - replaced with an oem unit, all good.

Paul

[M3KUK]

Bollox! This is the one I have bought, no good then?
http://www.ebay.co.uk/itm/BMW-E30-E-30- ... xyONBSXrg7

[paultv]

Not sure about bollox, but that was my experience - I reckon I paid about 75 euro for the one that worked, I'll check the make - and paid 40 for the one that never worked correctly.

looked like this one:

https://www.pkwteile.de/sachs/1219510

but Hella made.

Paul

[M3KUK]

I have messaged the Seller for his explaination.

[M3KUK]

Update, new fan seems to be behaving itself now!

[Brianmoooore]

New viscous will often behave a bit like an old seized one for a week or two, until the bearing frees up.

[M3KUK]

Cheers Mate!