Clutch Fan on 4.2 GQ question

Submitted: Sunday, Jul 11, 2004 at 18:36
ThreadID: 14569 Views:2079 Replies:4 FollowUps:6
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Hi guys,
I have finally found a way to get some good heat out of my shower set up, BUT my question to you all is....

I am considering a suggestion that was put forward to me by an owner of a GU. He uses this option to get the engine running hot enough to get maximum heat out of his shower setup without having to run the engine for long periods of time before engine warms up and without having to run it at high RPM.

His idea was simple but im not so sure it would do the silicon inside the clutch fan any good. This is what he does.

He has drilled a small hole in one of his fan blades on the outer edge. Then he ties the fan up with some string to stop it from turning. Seems easy enough but i am not so sure it does the silicone in the cltch assembly and good.

My question is.....
Does the silicone get harder as the engine temp rises and if so, wouldnt it do damage to the silicone if the clutch assembly wants to turn the fan more?

I ask this question as my interpretation of the clutch fan is that it gets tighter as the engine warms up. I could be wrong on just not sure about the idea of it.

Can anyone tell me if using string to hold the fan from turning does damage to the silicone in the clutch assembly. Its a great way to get to engine temp quickly but i'd like some feedback from you guys before I try it.
Thanks all

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Reply By: mr diamond - Sunday, Jul 11, 2004 at 18:50

Sunday, Jul 11, 2004 at 18:50
another simple option we use to get car hot for chemi weld or something is stick towell over the grill.
AnswerID: 67348

Follow Up By: cokeaddict - Sunday, Jul 11, 2004 at 19:13

Sunday, Jul 11, 2004 at 19:13
Diamond, I already do that mate thanks, I actually undo the 2 top radiator bolds (10mm) I think and slide a specially cut out piece of reflective stuff in there then do the bolts up again, but with the fan running, cold air still manages to get through slightly. And especially in winter I'd like to get as much hot shower water as i can as quickly as possible, but thanks for your input mate.
Regards Angelo
FollowupID: 328071

Reply By: Flash - Sunday, Jul 11, 2004 at 19:21

Sunday, Jul 11, 2004 at 19:21
The silicone actually gets less viscous as it gets hotter. What makes the fan "engage" is actually the bi-metallic strip (circular)on the hub which changes position as it gets hotter, which allows the silicone into a different portion of the hub (It all acts like a centrifugal pump).

I personally don't like the idea of disabling the fan with string..... New fan hubs are bloody expensive. If your engine thermostat is working properly (by blocking circulation of water thru the radiator when cold) it shouldn't make a lot of difference anyway.
AnswerID: 67355

Follow Up By: cokeaddict - Sunday, Jul 11, 2004 at 19:39

Sunday, Jul 11, 2004 at 19:39
Hmmmm ok thanks for that flash
Thermo is working as it should. Already checked it when fixing overheating problems earlier in the year.
Thanks again
FollowupID: 328075

Follow Up By: Flash - Tuesday, Jul 13, 2004 at 18:44

Tuesday, Jul 13, 2004 at 18:44
Another problem as far as your shower is concerned is that diesels don't "create" much heat at idle.
A idling petrol engine will heat up far more quickly than an idling diesel- in cool weather you could probably idle a diesel all day with no rad fan- not so on a petrol.
Diesels are almost "self cooling" at idle for two reasons: very little fuel going through, but a hell of a lot of air compared to petrol. (An idling petrol engine is using WAY more fuel than an idling diesel.)
FollowupID: 328295

Follow Up By: cokeaddict - Tuesday, Jul 13, 2004 at 21:19

Tuesday, Jul 13, 2004 at 21:19
Hey thanks for that Flash,
Very informative mate. Now i got abetter understanding of it.
Cheers Angelo
FollowupID: 328349

Reply By: lazylcd - Sunday, Jul 11, 2004 at 21:42

Sunday, Jul 11, 2004 at 21:42
hi coke,

whats the latest with the overheating issues, i havent seen any updates lately, please keep us posted , here and on the GQ list if u dont mind.

AnswerID: 67379

Follow Up By: cokeaddict - Sunday, Jul 11, 2004 at 23:15

Sunday, Jul 11, 2004 at 23:15
hey Leighton,
whats your email mate. I'll send you the update.
Also where's the GQ list you refer too?
FollowupID: 328112

Follow Up By: lazylcd - Monday, Jul 12, 2004 at 23:33

Monday, Jul 12, 2004 at 23:33

this site, the yahoo group, (aka unsnappedcoin) post it here or send to

hope to hear from u soon

FollowupID: 328238

Reply By: Gerry - Monday, Jul 12, 2004 at 11:31

Monday, Jul 12, 2004 at 11:31
Hi, I agree with Flash above, the bi-metallic operates a small slide valve in the GQ unit which effectively blocks the passage of the silicone fluid internally, thus locking the whole thing up. The valve is only a small strip of spring steel which fatigues and breaks (I know 'cos I've had one go on mine and cut it open to have a look) so I certainly wouldn't tempt fate and put any more undue strain on it by tying the fan up unnecessarily.
AnswerID: 67422

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