New Viscous Fan Coupling

Sean d

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I can stop mine with my finger, not sure what mechanic I got that off :whistle:
 

Mint

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I can stop mine with my finger, not sure what mechanic I got that off :whistle:
You wouldn't want to try that with this new one Sean, you'd be a finger or two missing;)
 

Sean d

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You wouldn't want to try that with this new one Sean, you'd be a finger or two missing;)
I believe it should stop easily if its good, is that right @t-tony, if not I best get iut changed as I have some big cruises coming up
 

Mint

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I believe it should stop easily if its good, is that right @t-tony, if not I best get it changed as I have some big cruises coming up
This new one is totally different to the old one. With the engine not running there is a lot of resistance to spinning the fan. Whether that is because it's new and needs to 'bed in' I don't know...
TBH as long as the car is moving you wont have any cooling issues, mine were caused by idling with no movement
 
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Sean d

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This new one is totally different to the old one. With the engine not running there is a lot of resistance to spinning. Whether that is because it's new and needs to 'bed in' I don't know...
Best not stick ones finger in then pal :D
 

t-tony

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I believe it should stop easily if its good, is that right @t-tony, if not I best get iut changed as I have some big cruises coming up
I used to stop all viscous fans by finger, but then I was young and daft ...................... Don't ;)=))

Tony.
 

Synclare

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My current one has a lot of resistance to turning when cold .Once spun manually by hand a few times it frees up a little and will a couple of revs before stopping.
 

MalcQV

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Just replaced mine.
Seems to have done the trick, so far so good but I can hear it engage now when the gauge needle goes slightly above half.
The old coupling was not that old it seems as the date stamped on it was 22/02/18. It still had resistance to turn but nowhere near as much as the new one. Time and hot days will prove all is well I guess.
https://zroadster.org/threads/overheating-in-the-hot-weather.30129/#post-492575
 

Ianmc

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If you have aircon, these fans are not necessary IMO. My early 1997 car didn't have one from new. If the temp starts to rise, the electronic (AC) fan cuts in happily.:thumbsup:
 

t-tony

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That's the reason some people do the fan delete, BMW proved you don't need it, well not in our climate but maybe somewhere hotter you might.

Tony.
 

roadvoyager1

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If you have aircon, these fans are not necessary IMO. My early 1997 car didn't have one from new. If the temp starts to rise, the electronic (AC) fan cuts in happily.:thumbsup:
After reading several horror stories on here about the fan blades breaking up and taking the radiator out with it I decided to go down the fan delete route. In addition to taking the viscous coupled fan off a lower temperature thermostat should be fitted. Easy on a 6 pot, where a 4 pot stat being 8 deg C lower (IIRC) is ideal. The a/c fan cuts in to cool the radiator when required. I have not had need to look into sourcing a lower temperature stat for a 4 pot, perhaps somebody else can add that info.
Although there have been some concerns expressed about overheating I have had no issues in the UK or France in with air temperatures up to 36 deg C. If I were going to drive in high altitude during the height of summer I would consider refitting a viscous coupled fan, l otherwise I am happy to do without.
 

antodeco

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I'll be doing this shortly. Mine is overheating in traffic. Both hoses get boiling hot and firm when on.
The fan is on from the moment the engine is turned on, and when engine is off, it's quite easy to turn it freely. I assume that suggests it's knackered?
 

the Nefyn cat

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I'll be doing this shortly. Mine is overheating in traffic. Both hoses get boiling hot and firm when on.
The fan is on from the moment the engine is turned on, and when engine is off, it's quite easy to turn it freely. I assume that suggests it's knackered?
If the top and bottom hoses are both getting hot at the same time that would suggest that the radiator isn't cooling properly, the top hose should be hot once the thermostat opens and the bottom hose should be a lot cooler, that's the way it's supposed to be. The rad may be silted up, normally caused by past use of dodgy water to top up with, or Radweld or something similar being put in.
As for the fan, it should spin freely with the engine off and cold, and should start getting harder to turn once it's warmed up (again, engine off). Waste five minutes on this
View: https://www.youtube.com/watch?v=LpzJsav3rsw
, may help explain better than I can.
 

Mint

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the Nefyn cat

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If I remember how I was taught this stuff, the fan should be fairly free-spinning cold, and get stiffer as things get hotter, I remember back in my fleet maintenance days with loads of Transits you could always spot the ones with a knackered viscous hub by the howling of the fan starting from cold. I guess they can fail both ways, not enough or too much.
And I took the fan off my own Z3 a couple of years ago and I've had no troubles with it at all. Wouldn't recommend it to everyone, round here there ain't a lot of traffic, and it doesn't spend a lot of time sitting around running. A traffic jam here tends to be a few :baa:baa:baa wandering about, not the awful snarl-ups I remember from living dahn sarf.
 

Mint

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...round here there ain't a lot of traffic, and it doesn't spend a lot of time sitting around running. A traffic jam here tends to be a few :baa:baa:baa wandering about, not the awful snarl-ups I remember from living dahn sarf.
Agree as long as I was moving, no problem but sat in traffic, or on the MOT ramp is when I had my problem. The old fan spun very freely when cold but the new one doesn't.
 

the Nefyn cat

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So long as it works, that'll do. I have wasted time in the past trying to sort out an overheating problem, doing all sorts with fans and thermostats only to find out that the rad wasn't working properly. Bl**dy Radweld.
 

EnthuZiaZT

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Zed Engine overheating is something we all need to be aware of. My first Zed 3, a Silver 1,8 overheated after many miles of motorway driving, in France many years ago. It was 38 Degrees and we were doing 115 mph. Strangely enough it was when we slowed right down at the ferry terminal that the temperature gauge went up to boiling point. The engine was kaputin after that, it leaked oil everywhere and was prone to overheating even after a new radiator was put in. So I sold it and bought Mora!

Mike
 

antodeco

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Quick one on this. When cold, and engine off, my fan will turn a little by hand (1/4 rotation maybe). However, when hot, and engine off, it rotates alot more freely. I thought it was meant to be the opposite?
 
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