viscous fan disintrigrated

Headed off towing caravan today to see mother in law for her 90th birthday. Hardly got out of Weymouth climbing the hill, gear changed down then a huge bang and steam everywhere . Lifted the bonnet and found bits of Viscous fan blades and bits of the radiator cowl shattered and the top hose blown off the radiator . The recovery driver reckoned he had never seen that before. No other apparent damage, in fact when I refilled the radiator with water no leaks or anything. Have ordered a rad cowl from Emmotts and viscous fan and rad cap from Island 4x4. Hopefully be mobile again soon.

Hi enery8, sorry to hear about your mishap but the same thing happened to my P38 2.5 DT about two years ago, the pulley on the water pump sheared off and destroyed the viscous fan and the radiator. Got a new water pump and a fan and radiator from emmotts, been no trouble since apart from usual electrical gremlins. Must be a weakness with these engines, hope you get it sorted ok.

:rolly: Better try figure out what caused it if you can

Most common is the VC unit seizes causing the fan to overspeed and shatter.....

Saint.V8 said:

Most common is the VC unit seizes causing the fan to overspeed and shatter.....

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isn't it made to take full speed?

Druim said:

isn't it made to take full speed?

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It should never lock solid, if it does the fan would run faster than engine speed and the load on it can cause old blades to flex and break.

Thank you everybody for your answers. The viscous unit is still turning freely although I suppose it may have been momentarily seized. I still have the problem with the auto box flaring and fan shattering seemed to occur as it changed down going up a steep hill. It was a particularly hard gear change and we were towing a large caravan, rig well loaded. I wonder if the gearbox problem might have some bearing on the current problem.

Do the aircon fans mod as back up. If it's diesel, bin the viscous and cowl.

Datatek said:

Do the aircon fans mod as back up. If it's diesel, bin the viscous and cowl.

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Morning Keith,
I did your aircon fans mod ages ago and they are working as they should. It is diesel. Are you saying it will run okay without viscous, fan and rad cowl? Still finding bits of fan around the engine. I have got the viscous unit off now, easy thanks to this forum.
I have already ordered the viscous fan unit from Island 4x4 and the cowl from Emmotts and they should arrive tomorrow so not sure what to do, should have asked the question first :doh:
I guess I could just leave them unpacked and then fit them if I decide to sell the car. (Good chance of that at the moment!!!)

enery8 said:

Morning Keith,
I did your aircon fans mod ages ago and they are working as they should. It is diesel. Are you saying it will run okay without viscous, fan and rad cowl? Still finding bits of fan around the engine. I have got the viscous unit off now, easy thanks to this forum.
I have already ordered the viscous fan unit from Island 4x4 and the cowl from Emmotts and they should arrive tomorrow so not sure what to do, should have asked the question first :doh:
I guess I could just leave them unpacked and then fit them if I decide to sell the car. (Good chance of that at the moment!!!)

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If the cooling system is good, it will run fine with no viscous and even better with no cowl.

Thanks Keith. I think the cooling system is fine.
It did not overheat when the fan shattered although it must have pressurised cos' it blew the top hose off the radiator. Lucky - at least it did not blow the rad.

enery8 said:

Thanks Keith. I think the cooling system is fine.
It did not overheat when the fan shattered although it must have pressurised cos' it blew the top hose off the radiator. Lucky - at least it did not blow the rad.

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Filler cap should have gone fail safe long before hose blew off. They are supposed to fail to relive pressure and protect system at around 22 PSI.

enery8 said:

Thanks Keith. I think the cooling system is fine.
It did not overheat when the fan shattered although it must have pressurised cos' it blew the top hose off the radiator. Lucky - at least it did not blow the rad.

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What caused it all did the top hose blow and go into fan or did fan seize chatter taking off top hose

enery8 said:

Headed off towing caravan today to see mother in law for her 90th birthday. Hardly got out of Weymouth climbing the hill, gear changed down then a huge bang and steam everywhere . Lifted the bonnet and found bits of Viscous fan blades and bits of the radiator cowl shattered and the top hose blown off the radiator . The recovery driver reckoned he had never seen that before. No other apparent damage, in fact when I refilled the radiator with water no leaks or anything. Have ordered a rad cowl from Emmotts and viscous fan and rad cap from Island 4x4. Hopefully be mobile again soon.

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I've seen fans go before, the plastic fatigues with age and the over reving on shifts was probably more than it could stand. When my was flaring, I used the stick to control shifts so I could back off the throttle and then force the shift.

I'm half way through doing Datateks fan mod after finding broken blades and a hole in the cowling where a blade has done it's own version of The Great Escape. VC felt free but there was definitely a vibration and whirling noise as if the fan was being driven continously - and has overspeeded. Strangely 'the spanner' wouldn't shift the hub but trying to smash off the remaining blades did! Engine running fine with no fan, no upward temperature movement, even through an axious traffic jam. Need to wire in the thermostatic switch this weekend. Having no fan and cowling opens up so much space in front of the engine for the belts etc. Thanks Datatek for the sound economical advice.

Datatek said:

If the cooling system is good, it will run fine with no viscous and even better with no cowl.

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Seems they don't have the vc/fan in stock, looking at Monday delivery so cancelled it. Going to fill up the water/antifreeze and forget about the fan and cowl. If it is good enough for Datatek its good enough for me!!!
Anyway, need to get to Luton to the mother in laws party so here we go!
Thanks for all your input, help when needed as usual
Bill

Datatek said:

If the cooling system is good, it will run fine with no viscous and even better with no cowl.

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Hi Keith,
Just to let you know I put it back together without the VS/fan and had an uneventful 150 mile journey to Luton today. Thanks again for the sound advice.
Bill

enery8 said:

Hi Keith,
Just to let you know I put it back together without the VS/fan and had an uneventful 150 mile journey to Luton today. Thanks again for the sound advice.
Bill

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Good news Bill and it saved you a few bob. Do you want my Paypal address?

Update: After our trip to Luton car seems to loose power. Spent quite a while looking for the problem that turned out to be a hole in the small hose between the intercooler and turbo. A shard of plastic must have nicked it and then driving it on the 300 odd mile journey must have enlarged the hole to about the 6cm I found. Unbelievable that I could not get that short, straight pipe locally.

One upshot of this was that I bought a new Viscous Fan Assy from Paddock and was told that because of the failure rate of the after market fans even their suppliers had stopped selling them.

??????? If the mod worked , why put the V/fan back?