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Viscous fan unit

Hi, would appreciate a bit of advice please. 200TDi Defender, overheating under load problem and while flushing the rad noticed the fan unit can be spun very easily when at running temp so suspect I'll need to swap the unit out. I presume the viscous gel is not replacable, but have found a comment for a Toyota on another site :-

"My mechanics solution was to strip off the unit and drill a hole into the hub as close to the centre as poss, thread the hole ready to receive a grub screw, buy the gel from Toyota and fill a hypodermic syringe with it . He fitted the syringe with a wide bore needle and forced the gel into the hub and sealed the hole."

Anybody tried it on a 200TDi? I'm guessing the effort and gel cost probably outweigh the cost of a replacement.

Alternatively, does anybody have a spare radiator, thermostat and viscous fan unit on them? Or know the cheapest place to get them?

Cheers!

Dave.

Reply to
Dave
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After doing some more web site research it appears that my viscous unit may not be buggered after all. It's difficult to find out how one actually works. Some sites say the liquid gets thicker under heat, others say the centripetal force squeezes the liquid into another chamber. Either way, I can stop the fan by hand when the landy is at normal running temperature. Is that normal? Or should I have lost a couple of fingers?

Dave.

Reply to
Dave

Not sure of the exact count.

Research the archive of this group for posts on the subject - by Austin I think.

Reply to
William Tasso

Well there should be 8 + 2 thumbs, but it's a hellova way to test anything on a car.

Reply to
jg

At normal operating temperature I'd expect it to be free-wheeling.

Remember, too, that it is the air sucked over the radiator whose temperature is being sensed. Hence if the radiator core is blocked internally or externally the coupling will not detect 'overheating' and will fail to lock up.

If you read back through this group you'll find frequent mentions of viscous coupled fans. When working normally they'll be obviously noisy for about a minute from cold start than begin to freewheel until needed.

I'm not familiar with the thermostat on this model but I think it does not have the skirt as on the 2.25l which is essential to proper operation on that model.

Barring head gasket and other such problems, my money's on the radiator itself being your problem.

Reply to
Dougal

For what it's worth the viscous fan on my 300tdi 90 also, can be stopped with little effort at an indicated working temperature. Matter of fact I've never got the fan to lock up ever. I can only guess that it will lock up when towing heavy loads in the height of the summer, I know it never overheats.

Neil

(Reply via NG please)

Reply to
Neil

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