Viscous fan

shaunm41 · Jul 16, 2009

Its been confirmed that my viscous fan is knackered on the 2.5 BMW diesel.. I mentioned in another thread about a kenlowe electric fan but as funds are low, as a tempory measure would a fully working viscous fan from a 3.9 v8 classic fit on my 2.5 deisel? They look pretty much the same so I wouldnt see why not but just thought I would check..

Thanks

zzr1200 · Jul 16, 2009

I don't think the fans unit are the inter-changable, a complete new viscous unit is probably cheaper than a Kenlow Kit:

Viscous Coupling Assembly P38 2.5TD BMW PGG101290 Island 4x4 - Specialists in Land Rover and Range Rover Parts and accessories for all models. UK and worldwide mail order.

shaunm41 · Jul 16, 2009

Decided to just try it anyway to see what happened.. The fan blades were bigger at the back and caught on one of the rad pipes but I managed to take the viscous coupling off and swap them over, it was pretty much the same and fitted straight on.. Seems better now, spinning faster for a start.. Before I could stop the fan with my bare hand with the engine running, now it hurts.. haha.. But how exactly does a viscous fan work? When i first put it on and started it up the fan was roaring like mad when revved then it stopped roaring... It spins, and spins faster at higher revs.. but curious to know how it works....

Irishrover · Jul 16, 2009

It's filled with a "Liquid" that is fluid when it is cold, allowing the fan half of the coupling to slip and therefore not draw much air in. As the engine temperature increase the "Liquid" starts to gel which increases the grip to the fan half and it draws in more air. When the engine is hot, the "Liquid" virtually solidifies which gives a full drive to the fan for maximum air flow.
Hope this explains it.:behindsofa:

landy10 · Jul 16, 2009

Irishrover said:
It's filled with a "Liquid" that is fluid when it is cold,

Loada cock,
Its a bi-metal strip the same as on a thermostat in your house central heating. cant remember what the two metals are that are wound together but one expands quicker thatn the other when hot and the spring expands gripping the sides of the to halfs and locking them together :doh:

gavbriggs · Jul 16, 2009

now now boys you are both right, well sort of!

Viscous

and

Viscous coupling unit - Wikipedia, the free encyclopedia

gemsdad · Jul 16, 2009

gavbriggs said:
now now boys you are both right, well sort of!

Viscous

and

Viscous coupling unit - Wikipedia, the free encyclopedia

well done gav,they are both correct but irish has got his viscous items a bit mixed up i think.your quiet ternight.wass up doris got a headache or summat.

gavbriggs · Jul 17, 2009

trying to work out which wires are for the touch funtion!

gemsdad · Jul 17, 2009

gavbriggs said:
trying to work out which wires are for the touch funtion!

get to yer pit yer nob,do it tomorrow or summat.:doh:

gavbriggs · Jul 17, 2009

yep, ive given up, gonna buy a new one me thinks!

gemsdad · Jul 17, 2009

gavbriggs said:
yep, ive given up, gonna buy a new one me thinks!

buy a new what mate.

wammers · Jul 17, 2009

shaunm41 said:
Decided to just try it anyway to see what happened.. The fan blades were bigger at the back and caught on one of the rad pipes but I managed to take the viscous coupling off and swap them over, it was pretty much the same and fitted straight on.. Seems better now, spinning faster for a start.. Before I could stop the fan with my bare hand with the engine running, now it hurts.. haha.. But how exactly does a viscous fan work? When i first put it on and started it up the fan was roaring like mad when revved then it stopped roaring... It spins, and spins faster at higher revs.. but curious to know how it works....

Test for viscous fan. You should be able to stop fan from turning with your hand when engine is cold. But not when engine is hot. Fans should never lock up solid. If you cannot stop fan when engine is cold it is fooked. If you can stop fan when engine is warm it is fooked. But i would suggest a suitable piece of wood rather than a set of fingers for this test. Place wood gently against fan when engine cold and start up, fan should be easy to hold from turning. Place wood gently against fan with engine hot and start up, fan should push wood away. Obviously do this carefully.

Viscous fan

shaunm41

New Member

zzr1200

Well-Known Member

shaunm41

New Member

Irishrover

Well-Known Member

landy10

New Member

gavbriggs

Well-Known Member

gemsdad

NOT BOTHERED.

gavbriggs

Well-Known Member

gemsdad

NOT BOTHERED.

gavbriggs

Well-Known Member

gemsdad

NOT BOTHERED.

wammers

No longer with us, RIP

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