Viscous Fan Information Needed.

[Homestar]

Well, I managed to confirm something that has been bugging me since I've had this car - that is the noise the fan makes all the time. On the weekend Fraser130 and me had our machines side by side, so we were comparing different things about what they do and don't, and what certain things are supposed to sound like. When Fraser130 started his, after only a few seconds, the viscous fan starts to disengage, and all that is left is the noise the engine makes.

Mine on the other hand doesn't, and after driving it home I checked it, and it is close to locked up all the time. We were both a bit stumped by this, as other viscous fans I've had that die do the opposite - not lock up at all even when very hot.

So, my question is to anyone out there that knows anything about these is what would cause it to stay locked up like this???

Going to order a new one at some stage, but just thought i'd put it out there to see if there are any ideas about it.

Cheers - Gav

[bee utey]

The viscous fan clutches I have had a play with are fitted with a spiral bi-metallic spring on the front. This moves the small shaft that controls the fluid flow inside. So you can unship the spring out of its slot, and manually move the shaft to either lock or unlock. You can also test the bi-metallic spring movement with a small gas torch. I bend the spring hook end on certain hubs to lower the cut-in temperature as I want a slightly cooler running engine than stock.

So to summarise, your clutch could be stuck either on or off due to a control shaft fault.

[harlie]

Without a copy of RAVE at work – what controls the clutch, surely it can’t be a thermo spring?

When I start leave in the morning the fan runs for about 1 minute and then cuts out if the AC is not on. If the AC is on the fan stays running even with the engine stone cold. I hate the extra noise of the fan especially when the engine doesn't need it.

[fraser130]

Without a copy of RAVE at work – what controls the clutch, surely it can’t be a thermo spring?

When I start leave in the morning the fan runs for about 1 minute and then cuts out if the AC is not on. If the AC is on the fan stays running even with the engine stone cold. I hate the extra noise of the fan especially when the engine doesn't need it.

Harlie, I think Gav means the engine driven fan, the electric "Auxilliary cooling fan" is the electric one, the reason it comes on with the aircon is to keep the pressures down in the aircon system by minimizing the condenser temperature. That's on my "to do" list as mine never comes on!

[bee utey]

I recall seeing a pic of a modern viscous fan on an engine with an electrical connection. ECU controlled on your vehicle?

[harlie]

yeah it must, I'm talking about the belt driven fan - on mine it runs when the ac is on no mater what the engine temp, it's the one that makes all the noise, looks like some reading tonight. I've not checked the aux fan, maybe that's my problem.

[Homestar]

I recall seeing a pic of a modern viscous fan on an engine with an electrical connection. ECU controlled on your vehicle?

I don't think so - I know they use these on some small trucks - Borg Warner make one, but when I looked up to purchase a new one, it looks like a plain old fashioned viscous. It doesn't seem to have a spring on the front, everything must be internal. This link to flea bay shows some photos - RANGE ROVER L322 3.0L DIE VISCOUS FAN COUPLING ASSEMBLY | eBay (http://www.ebay.com.au/itm/RANGE-ROVER-L322-3-0L-DIE-VISCOUS-FAN-COUPLING-ASSEMBLY-/370562546448?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item56473fbb10)

Cheers - Gav

[bee utey]

I don't think so - I know they use these on some small trucks - Borg Warner make one, but when I looked up to purchase a new one, it looks like a plain old fashioned viscous. It doesn't seem to have a spring on the front, everything must be internal. This link to flea bay shows some photos - RANGE ROVER L322 3.0L DIE VISCOUS FAN COUPLING ASSEMBLY | eBay (http://www.ebay.com.au/itm/RANGE-ROVER-L322-3-0L-DIE-VISCOUS-FAN-COUPLING-ASSEMBLY-/370562546448?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item56473fbb10)

Cheers - Gav

It's still a bimetallic spring, it presses inwards instead.

https://www.aulro.com/afvb/images/imported/2012/03/858.jpg


Fan clutch - Wikipedia, the free encyclopedia

[Blknight.aus]

if your ac fan runs anytime that the engine does then at some point your ECU has logged an overheat fault, one of the first things it does is manually trigger and lock in the fan control to attempt to get you some airflow. (IT does help I did a heap of experimenting with one of my V8 discos in ambients below 25ish degrees with the AC turned off an manually run the AC fan is enough to keep the engine under overheat temps without an engine fan even in mild stop start traffic.)

[Homestar]

It's still a bimetallic spring, it presses inwards instead.

https://www.aulro.com/afvb/images/imported/2012/03/858.jpg


Fan clutch - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Fan_clutch)

Do you think it is servicable? Not that a new one is too expensive, but I don't like forking out $$$ unless I absolutely know it cannot be fixed.:)

[bee utey]

Do you think it is servicable? Not that a new one is too expensive, but I don't like forking out $$$ unless I absolutely know it cannot be fixed.:)

I've never fixed one as they are all sealed up. But you can still have a look at yours, remove it first, play a bit of heat on its spring and see if it moves.

[Blknight.aus]

some of the early non OEM ones can have and access plug so that you can change the fluid. Ive taken one apart for the hell of it but you'd want to be a bloody good ally welder to get one back together again.

[Davehoos]

the type shown with the straight bimetal apear to work or be stuffed.
I think the type used on early falcons might be the type that use variable viscocity fluid-becomes thicker with heat-like mitubishi sigma-L300.

--ive tried to adjust the operation temperature without sucsess often you just fill these up and put up with the fan noise..these are match to the job,radiator and fan blade so it its operation is changed it often wont work

refilling..i have had sucsess with some old units drilling a hole in the center of the mounting flange.by experimenting with the fliud type and amount ive been able to get the fan to operate.

a company in newcastle reconditions visco hubs.
bearing issues it has to be a very expencive unit to bother with.

[neil 90]

Hey Gav,

please let us know if the new one fixes your problem, mines doing the same, it drives you mad

cheers

neil

[Summiitt]

Can anyone comment on what tyres to fit to my 04 td6 rangie, I am looking for an all terrain or better as I do a lot of dirt road driving. Had a bad run with coopers on my defender so am looking at perhaps Mickey ts or perhaps generals?has Anyone had some real world experience with any brands on these 18in rims in the bush? looking to get into some decent off road driving as well, so a good all rounder is what I'm looking for. Thanks

[Homestar]

Hey Gav,

please let us know if the new one fixes your problem, mines doing the same, it drives you mad

cheers

neil

Will do Neil, but you may have to wait a bit. I've just ordered brakes for it, so my spending for the month is done:p

Next month it will be due for a service, so it may be a while before I get around to replacing it....

[neil 90]

Thanks Gav, im hearing you on the spending, ive had 2 years trouble free but in the last month ive got a list that goes!!!

torque converter
all suspension bushes
tyres
FSR
brakes all round.

cant complain its only wear and tear, done 212,000 and got 70,000 out of my scorpion atr's. things do seem to come at once though.

still loving it !!!:)

cheers

neil

[andrew e]

I don't know much about the working of the viscous, but I do know that they have an anticlockwise thread ( turn clockwise to remove), unlike most other lr engines.

Andy

[Homestar]

Well, I've had a development on this - instead of the fan being locked up all the time, it is now gone quiet - I am assuming it has failed, and is just free wheeling now, although I haven't checked yet. Maybe the viscous locking up is the first sign that it's about to **** itself completely? Not sure, but I love that it doesn't roar all the time like it used too. I can drive it around with the windows down now:)

I'll have to keep an eye on the temp though until I get a replacement, but driving around town today the temp gauge didn't move, but it is a tad chilly out...

[fraser130]

Gav, mine doesn't come on unless it's over maybe 27 degrees and I have the aircon on, and I've been sitting at the lights for a bit. I have a digital readout (thanks to the Intravee) and it is always around the 91 degree mark (give or take) The gauge shows normal from 72-98 (highest I have had it - hot day, towing) and it only runs for the first 15 seconds or so when I take off....

Cheers,

Fraser

[Homestar]

Mmm - may have to wait a while to get another 27 degree day...:p I will be getting the intravee in the next month or so though, so I'll do what you have done and map the engine temp through to the display and keep an eye on it.

Cheers - Gav