Noisy fan - Page 2

Denzlepob · Mar 18th, 2009, 11:37

I am going to jump in and get my hands dirty.

marcmarel · Mar 18th, 2009, 12:01

That's always a good idea. If you remove the fan and let it sit "frontside down" overnight, the oil should drain to the reservoir. And the fan should spin freely, as it should in the car.

You can look at the position of the bimetal valve, closed (normal running position) it should be perpendicular to the bit that's stuck in it's anchoring post.
Heat it and bimetal will twist it open. If you heat it and nothing happens it's stuck.

Denzlepob · Mar 18th, 2009, 12:43

I've got a hot air gun, I will use that.

Denzlepob · Mar 18th, 2009, 15:04

Managed to whiip the old girl out, Aisin K6 stamped on the casing, the pivot point connected to the element was siezed, gave it a few taps with the blunt end of a screwdriver which freed it up, the oil inside was very thick. I re-assembled and re-fitted, ran her up and noticed that the fan rotations matched the engine revs, clutch had no effect. Does that oil thicken after time?

BrianH · Mar 18th, 2009, 15:18

This is really interesting.

I have tried Brandon Motors replacement but no difference with the temperture guage climbing at idle in hot weather until it switches in Kenlow electric fan.

The mechanical thermo-swich for the fan has failed twice due to poor protection over the years. Once in central London, then when I was away too long on tickover to observe the temperature guage, then poooshhh.

I always wondered if the electric fan resticted the air flow.

But now this is really interesting...Thanks

BrianH

Denzlepob · Mar 18th, 2009, 16:49

A few pictures.

marcmarel · Mar 18th, 2009, 18:49

The oil inside is supposed to be very thick, thicker than honey, barely moving at all.
After you freed the bimetal operated valve, did it return to it's open position? I had to recoil the bimetal a bit: pry it out of it's anchor point and wind it up/down, I can't remember which way. I "tuned" it so that a relaxed (cold) bimetal corresponds to an open valve.

Mind you, I just finished this exercise and don't know how it will hold up in the long run.

Denzlepob · Mar 18th, 2009, 20:28

Pictures are here:

http://picasaweb.google.co.uk/dennis...Lam6aKGjqSxaQ#

marcmarel · Mar 18th, 2009, 21:08

That's it. Mine looked exactly the same inside and out. On the picture with the two halves separated look at the one on the right. You can see two small round holes near the edge, that's where the oil is flung out to the reservoir, and one square and two curved openings more to the centre, these are opened by the bimetal spring so the oil can return to serve it's purpose.

A fan that lets the engine overheat has leaked out the oil (it's silicone oil), so it never really engages. You could add oil, 3000 cSt. is the viscosity, but it might leak out again of course.

Denzlepob · Mar 19th, 2009, 08:20

Can I ask members to go out and spin the blades of their cooling fans obviously with the engine off and let me know how freely it spins?

Cheers.

Mar 18th, 2009, 11:37	#11
Denzlepob New Member Last Online: May 17th, 2009 13:00 Join Date: Feb 2009 Location: Dorset	I am going to jump in and get my hands dirty.

Mar 18th, 2009, 12:43	#13
Denzlepob New Member Last Online: May 17th, 2009 13:00 Join Date: Feb 2009 Location: Dorset	I've got a hot air gun, I will use that.

Mar 18th, 2009, 15:04	#14
Denzlepob New Member Last Online: May 17th, 2009 13:00 Join Date: Feb 2009 Location: Dorset	Managed to whiip the old girl out, Aisin K6 stamped on the casing, the pivot point connected to the element was siezed, gave it a few taps with the blunt end of a screwdriver which freed it up, the oil inside was very thick. I re-assembled and re-fitted, ran her up and noticed that the fan rotations matched the engine revs, clutch had no effect. Does that oil thicken after time?

Mar 18th, 2009, 15:18	#15
BrianH VOC Member Last Online: May 3rd, 2024 12:56 Join Date: Apr 2006 Location: Bournemouth	This is really interesting. I have tried Brandon Motors replacement but no difference with the temperture guage climbing at idle in hot weather until it switches in Kenlow electric fan. The mechanical thermo-swich for the fan has failed twice due to poor protection over the years. Once in central London, then when I was away too long on tickover to observe the temperature guage, then poooshhh. I always wondered if the electric fan resticted the air flow. But now this is really interesting...Thanks BrianH

Mar 18th, 2009, 16:49	#16
Denzlepob New Member Last Online: May 17th, 2009 13:00 Join Date: Feb 2009 Location: Dorset	A few pictures.

Mar 18th, 2009, 18:49	#17
marcmarel Member Last Online: Mar 3rd, 2011 10:40 Join Date: Jan 2007 Location: Maasland	The oil inside is supposed to be very thick, thicker than honey, barely moving at all. After you freed the bimetal operated valve, did it return to it's open position? I had to recoil the bimetal a bit: pry it out of it's anchor point and wind it up/down, I can't remember which way. I "tuned" it so that a relaxed (cold) bimetal corresponds to an open valve. Mind you, I just finished this exercise and don't know how it will hold up in the long run.

Mar 18th, 2009, 20:28	#18
Denzlepob New Member Last Online: May 17th, 2009 13:00 Join Date: Feb 2009 Location: Dorset	Pictures are here: http://picasaweb.google.co.uk/dennis...Lam6aKGjqSxaQ#

Mar 18th, 2009, 21:08	#19
marcmarel Member Last Online: Mar 3rd, 2011 10:40 Join Date: Jan 2007 Location: Maasland	That's it. Mine looked exactly the same inside and out. On the picture with the two halves separated look at the one on the right. You can see two small round holes near the edge, that's where the oil is flung out to the reservoir, and one square and two curved openings more to the centre, these are opened by the bimetal spring so the oil can return to serve it's purpose. A fan that lets the engine overheat has leaked out the oil (it's silicone oil), so it never really engages. You could add oil, 3000 cSt. is the viscosity, but it might leak out again of course.

Mar 19th, 2009, 08:20	#20
Denzlepob New Member Last Online: May 17th, 2009 13:00 Join Date: Feb 2009 Location: Dorset	Can I ask members to go out and spin the blades of their cooling fans obviously with the engine off and let me know how freely it spins? Cheers.

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