Test Fan Viscous Coupling
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ukadamwest
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rolled up copy of LRO International or Readers Wives..if it stops the fan spinning its fooked
norseman
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+ 1 for the rolled up paper/mag.
Better still use the Sun, all that's any good for
If it's a 3.5efi it should have an 11 blade fan, carb versions were 7 I believe.
Better still use the Sun, all that's any good for
If it's a 3.5efi it should have an 11 blade fan, carb versions were 7 I believe.
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If it is like the P38 it will be locked on startup, loosen up and go quiet as it warms and then tighten up again when hot to stop overheat.
If loose all the time and can be stopped with a newspaper it is stuffed. If solid all the time and shreds the paper then it is stuffed.
Datatek
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Yes
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With the engine cold, start and rev it once, let idle for a minute or so then stop it. The fan should then be turnable by hand. It should free up further the more it is turned. If it is stiff to turn and cannot be stopped with your finger tips at cold idle it is on it's way out. DO NOT try the finger tip test if you don't know what you are doing.
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View attachment 187930 he didn't know what he was doing!!!
Obviously not a time served mechanic of more than fifty years standing. Who still has all his fingers.
Datatek
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Not as far as I'm aware, the fan is bolted/riveted to the viscous coupling. You could always bin it and fit an electric fan.
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It is a complete unit as you say. Some fit the fan from a 300 Tdi which does have a separate fan and viscous unit.
Thanks. It is a separate unit, with bolts through the rear of the fan. I was just wondering if it could be removed by just removing these bolts.
If the viscous drive is working correctly should it be impossible to stop the fan with a newspaper or just require a great deal of pressure?
If the viscous drive is working correctly should it be impossible to stop the fan with a newspaper or just require a great deal of pressure?
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tomcat59alan
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You will know, if it stops it's fecked, if you get covered with confetti its fine.
So it should be impossible to stop the fan regardless of how much pressure is exerted?
If it won't turn at all it's seized.
When cold the fan will be as Wammers has already said.
With the engine turned off & cold mine is stiff to turn by hand initially but as I continue to turn it it frees off to the point of freewheeling.
As things heat up & the clutch works it will become harder. I'd suggest being careful if you want to try that so you don't damage anything.
Bear in mind it uses a liquid to engage so is not mechanically locked together.
If yours does that it's fine.
Mine's a 1986 3.5EFi & I can remove the fan altogether complete with the viscous coupling by undoing the big nut in the centre which holds it onto the nose of the waterpump shaft & fit electric fans such as the Kenlowe instead. The big nut is on the engine side of the vc.
Helps to loosen the radiator shroud to ease lifting the fan assembly out once you've got the nut loose.
The fan can then be removed from the vc. by undoing the four bolts.
I did try the Kenlowe's but noticed b.all difference in fuel economy.
The main difference was the reduction in noise from the engine bay.
I can see an advantage if you do a lot of deep wading as you could fit an override switch to turn them off & not have them fling water all over the engine.
When cold the fan will be as Wammers has already said.
With the engine turned off & cold mine is stiff to turn by hand initially but as I continue to turn it it frees off to the point of freewheeling.
As things heat up & the clutch works it will become harder. I'd suggest being careful if you want to try that so you don't damage anything.
Bear in mind it uses a liquid to engage so is not mechanically locked together.
If yours does that it's fine.
Mine's a 1986 3.5EFi & I can remove the fan altogether complete with the viscous coupling by undoing the big nut in the centre which holds it onto the nose of the waterpump shaft & fit electric fans such as the Kenlowe instead. The big nut is on the engine side of the vc.
Helps to loosen the radiator shroud to ease lifting the fan assembly out once you've got the nut loose.
The fan can then be removed from the vc. by undoing the four bolts.
I did try the Kenlowe's but noticed b.all difference in fuel economy.
The main difference was the reduction in noise from the engine bay.
I can see an advantage if you do a lot of deep wading as you could fit an override switch to turn them off & not have them fling water all over the engine.
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Datatek
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It can always be stopped unless it's seized, but you would need to shove a length of 2 x 4 wood in there and it could be destructive
Datatek
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Not sure how you applied pressure, you should use a tightly rolled newspaper and stuff the end into the blades, if it either stops or slows dramatically it's fecked, if it shreds the end of the paper it's OK, engine hot of course.
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