Viscous Fan Testing

[Sirocco]

I just wanted to confirm with you guys exactly what the viscous fan should be doing.

My original one broke earlier this year which I got welded up (we were in Russia) and I had a new one sent to Mongolia which I never fitted until we arrived in Aus the other month.

Anyway, fitted it the other night and on my commute the temps get unto 100c on the way home (when the air is hotter). Its a 300tdi and has sat at 90c all year with fixed/welded up fan and previously in the UK with no issues.

I diagnosed the old one by putting a rolled up magazine into the fan blades, it stopped and I could hold onto it with my hand with no resistance... Goosed.

Well, the new one is doing exactly the same thing! I stopped quickly today to test it with the water temp at 100c and I managed to stop it with a piece of cardboard and then hold onto it with finger and thumb, no resistance.

Pretty cheesed off as a new one here isn't exactly cheap and I need one pretty quick really.

What do you all think? Is the new one duff? or am I missing something.

G

[ozrob]

Mate,
Have a look at this link
View topic - How do I test a viscous fan hub? | Australian 4WD Action
Basically the fan will lock up when cold from start up, then go quiet untill the bi-metal spring heats up and closes/opens the valve inside the hub, the fan should go noisy again...the hub is not a 100% physical lock thus you should be able to stop it using your method.
Is the radiator fins clean and not blocked, as the fan hub does need air flow over the radiator which then heats up the bi-metal spring.
I have noticed in this heat my fan is not noisy on the highway ( as there is sufficent air flow through the radiator) however; when say pulling off the highway into a service station fill with fuel and then driving off, the fan will lock up and go noisy.

[nedflanders]

The viscous relys on heat through the radiator to lock up, just check your radiator is clear.

[edddo]

see Question on 300tdi viscous fan

for more discussion on this.

My understanding is that 100 deg C may not be hot enough to 'lock up' the fan. So 100 Deg C is therefore within acceptable temp range for the 300tdi - I assume. No point fixing it if it is not broken - although I would also be happier with a steady 90 than seeing temps that high.

[Gerokent]

Screw it together with a couple of self tapping screws, problem solved for the life of the vehicle.

[Sirocco]

Well the new new (second) one is the same, so its not the viscous fan.

Am I just expecting too much from my 300tdi here? Do you guys normally see temps of 100c when its 40c outside?

It sits at 90c until a small hill before I get home then it reaches 100 and does not really come down from there.

When the old one was welded up I didn't have much trouble with it here.

Im thinking of replacing the water pump and coolant this weekend, maybe this is overkill, what do you think?

Rad was replaced 5 years ago, its had new tensioner/belt/bearing recently. Thermostat has been replaced/tested etc recently.

Heater fan blows red hot consistently so I don't think there are air locks.

hmmmmm...

G

[Judo]

Well the new new (second) one is the same, so its not the viscous fan.

Am I just expecting too much from my 300tdi here? Do you guys normally see temps of 100c when its 40c outside?

It sits at 90c until a small hill before I get home then it reaches 100 and does not really come down from there.

When the old one was welded up I didn't have much trouble with it here.

Im thinking of replacing the water pump and coolant this weekend, maybe this is overkill, what do you think?

Rad was replaced 5 years ago, its had new tensioner/belt/bearing recently. Thermostat has been replaced/tested etc recently.

Heater fan blows red hot consistently so I don't think there are air locks.

hmmmmm...

G

This is becoming a familiar story! In short, I experience everything you do. 90=normal. 100+ =pushing hard.

Much longer story:

I purchased a VDO temp gauge about a year ago. Looking back, I may not have done a lot of "hot" driving since then. Through winter in Melbourne and Victoria it gets into the 90's (mid?) but nothing serious. MAYBE up to 100* if I hit consistent 600* EGT. The last few months, I swear it's been getting much worse. Over 100* if I maintain over 500* EGT. A big freeway hill pushes the needle over 100* and then I back off. I suspect it would get to around 105* but that's a guess.

The question is, do I have too high expectations? Is this normal?

A few weeks ago I drained the radiator and did a DIY clean with some acidic stuff from Repco. New coolant. Did nothing. No change.

This week I bought a new radiator. Copper core, plastic tanks. New coolant. Installed it on a 40* day, went for a test drive and hit about 96* doing 60km/h on a flat road!!!!!! WTF?! If it wasn't for the fact that it was a 40* day, I would say that is much worse than my original radiator! I'm going to assume it's actually the same and the variation is the ambient temp.

Now I've been wondering about viscous fan....

Copy paste from another thread (where no one replied):

Engine cold and off I can spin the fan freely.
Engine hot (VDO gauge 90*) and off I can spin the fan freely.
Engine hot and idling, I cannot stop the fan in any way.
Engine cold and idling, I cannot stop the fan in any way (with any kind of cardboard or magazine). It is the same as hot and idling. It is a very effective shredder of paper though.

The last part seems to contradict most comments I've read?



So at this rate, I'm concluding that everything is normal!!! But I would like to finally confirm my viscous fan is working properly. Then I will give up and move on with life (read: County 110)



P.S. new thermostat a while ago too.

[lokka]

Hay Justin
this bit here
Engine cold and idling, I cannot stop the fan in any way (with any kind of cardboard or magazine). It is the same as hot and idling
Sounds familiar as the old mans 80 was drinking fuel and sounded like a diesel cessna 172 with the roar of the fan all the time

I could not stop the fan at all cold hot or anywere in between and I was using my trusty double plugga

Fitted a new clutch hub and gained on fuel econ and no more air prop unless the temps get up (towing van up hill)

My fan in the disco dosent roar to life unless the head temp (capillary gauge with sender bolted down to plug in top of water jacket)hits 110 deg
This freaks me out and makes me crease the seat cover but I can then hear the fan roar to life and the temp drops back

My dash gauge says half way and I have not seen it go past there since the reco and new bits wnet in just over 18 months back

I just think that these things are made to run hot mine has the turner improved head and I am not sure what they are tested at temp wise but I rekon I am getting mine on the high end of the scale

Next step is lowering EGT's with better inter cooling and getting the oil cooler out of the radiator