Viscous fan, Replace or fit twin electric fans

[madk1w1]

Since my Viscous hub is F'd, have refilled it with silicon oil and just leaks out the front around shaft with thermal spring on, what are everyones thougths on fitting electric fans with temp control, either twin or large single, or stick with viscous?????????

If you've done it what did you use?

Cheers
Madk1w1

[MQ MAD]

Stick with the viscous/clutch fan
They flow heaps more air than thermos

[hekarewe]

Stick with the viscous/clutch fan
They flow heaps more air than thermos

i would second that i had a viscus fan on the old pajero and went to twin thermo's and had never ending issues with the dam things corrossion in the wiring not enough current and the list just went on and on.
would spend rediclus amount of time making sure the current was right and everything was sorted each time i went off road there was nothing but issues, worst thing i ever did to the old girl.

[the evil twin]

X 3... viscous all the way for a recreational rig.

[Sean]

I have a 97 gq and have replaced raditor and fan and fan clutch car runs great... I have heard to many bad things with thermo fans..

[melts]

i ran thermos on my drift car and was not happy with the cooling under load, switched back to clutch fan and everything was sweet tempture wise.
my mate ran twin thermos and never had an issue.

i would opt for clutch fan, but if you ask my mate he would say thermos.
Personaly i think there is less to fail with a clutchfan and would backup 'hekarewe' comments about electrical issues etc with thermos.

[katwoman]

I currently have thermos that are going in the bin in the next month.. They are sh!te. They make too much noise and with electric water pump they dont do the job.. Some one spent $2000 putting this system in and it s*cks, big time !! I'm told GU cooling systems are better than most..
Kat

[madk1w1]

I currently have thermos that are going in the bin in the next month.. They are sh!te. They make too much noise and with electric water pump they dont do the job.. Some one spent $2000 putting this system in and it s*cks, big time !! I'm told GU cooling systems are better than most..
Kat


Seriously $2k that is OTT for any cooling system on a every day vehicle, after some research the dearest fan I found was only $350ish and a new stock radiator around the $450, hoses and control systems another 2-3hungy- being real generous (spelling) there, anywho what are the fans and how much for them????????

[katwoman]

I couldnt tell you what the fans are. Cant for at least two weeks when I get home. The radiator is a 5 core aluminium job, so thats prob most the dosh. The radiator bloke I went to see was gonna charge me $2k to put it back to original. I said thanks but, no thanks, I know where I can get a workshop manual and do it myself ! This system was in car when I bought it. Gonna try keep the radiator and fit clutch fan back on (??)So I dont know what they're worth. Mine's got 3. 2 on engine side and one on grill side.

[madk1w1]

Katwoman grille side should be AC fan, that radiator alone should keep it cool, viscous hub around the $300 mark depending on supplier, may need longer bolts in water pump for viscous and just unplug electric fans, ya radiator bloke sounds like a thieving so and so!!!!!!! sorry you're onwrong side of town i would help with fix and share a beer price tag, surely some good mechanical types over there that could help, no offence intended

[NissanGQ4.2]

I know everybody bags the thermo's but I don't find anything really wrong with them, yes it runs a little hotter under load or on a hot day sitting in traffic, not that i really know how hot it gets because i don't have a real temp gauge and the factory needle gauge means nothing at all. And i dare say i could overcome the heating problem in a number of ways.

1, Replace the Radiator, its pretty RS anyway
2, Get a custom shroud made up.

You can find my twin thermo thread here: http://www.nissanpatrol.com.au/forums/showthread.php?1336-My-Thermo-Fan-Pics

This is what i want 2 replace the original GQ shroud with, looking at the moment on cost 2 get one custom made

3646

Cheers

Todd

[katwoman]

You would think so, for some reason no-one wants to touch it cos they dont like aluminium rads (pros). Clutch fan on eBay ATM are around $110 plus fan blades. Will s*ck up to hubby to help me...

[XLR8]

I run twin AU/BA Falcon fans with a custom made shroud and thermostatic switch. Fans come in at about 70 degreees and the Q never gets over 1/3 on the gauge. I run 2 relays (1 for each fan) and a higher output alternator (110A) so draw on the power is not a problem. Mine is also drawing through the full size trans cooler that sits between the Rad and A/C cooler. The main thing is to make sure the fans can't draw air from the sides so the full shroud is a must. I also have a switch in the cab so I can shut them off for water crossings.

Can take some pics and post up if you're interested

[Mrowka]

I can see using twin electric fans for a seriously modified truck, but if your engine is basically stock, better to figure out what is causing the overheating and fix that.

[gec]

I run the same fans as XLR8 and they work real good cooling the 5.7 in my GQ so I would recommend them. One thing I found with them is when you take your rad out for a clean just pull your motors apart and give em a bit off a blow out and spray the bushes with CRC or something, give the brushes a clean and spray with silicon spray and they just like new again.

[boggy2006]

I think stick with the viscous fan as it provides some air flow all the time and responds instantly to throttle and provides massive airflow at high revs when climbing steep inclines. However, for very slow traffic (low engine revs and air flow) in extreme heat, the addition of an electric fan would help.

[XLR8]

As requested by Todd, some pics of my fans. Best I can get without pulling the rad out
http://i265.photobucket.com/albums/ii231/XLR8777/R16042011076.jpg
http://i265.photobucket.com/albums/ii231/XLR8777/R16042011073.jpg
http://i265.photobucket.com/albums/ii231/XLR8777/R16042011078.jpg
http://i265.photobucket.com/albums/ii231/XLR8777/R16042011074.jpg

[MQ MAD]

Katwoman,
New clutch fan hub yeah cheap as you mention
Clutch fan itself , depending are around $60 ish
Youll need a factory type rad shroud as well
Good 2nd handie should cost alot
The rad itself should be fine
Days work , bitta stuffn around and the thermos should be a thing of the past

Most patrols come with alloy radiators from factory
(They have the crappy plastic header tanks which split anyway)
A new copper core/steel header tank radiator should be under 600-700
Depending if you have manual or auto

[katwoman]

Thx for that. Am going to try to keep 5 core radiator (if clutch fan and blades fit). So will invent shroud.
Let ya know how it goes..

[WHITEGQ]

Hi,
I have been running twin AU-BA falcon thermo's since I got my GQ in 2009, due to the original viscus fan being in many pieces. I have the thermos wired through twin relays with twin switches, havent got thermostat controler yet, can have single speed fan on or off and second fan which is 2 speed, can switch between off, low and high speed, replaced radiator Febuary this year, have never had any over heating problems, most of the time have fans switched off, then if needed just switch on.

[NissanGQ4.2]

Thanks for the pics Mike :) really need to redo mine with a better shroud before next summer

[craig zoom]

stick whith the viscous

[Bigrig]

stick whith the viscous

Why mate?? ... personal experience??

[Robo]

5 core rad might be the problem.
If the core has the same fins design as a std core, then air flow is reduced and becomes inefficient and overheating is the result.
The thicker the rad, the more open it needs to be or air simply cant get through it.
This in turn causes the thermostat to be open more often and you will think it's running cooler but in fact its really struggling to do the job correctly.
Put in a new thermostat and temp should go middle of gauge.
Worm thermostat properly sits needle approx 1/3 or less even.
Thermostat stuck open runs the risk of over heating, water not in rad long enough to cool properly and this snow balls especially in hot weather.
The exact opposite in cold weather, with crook thermostat, it runs to cold and auto choke can cut in and run rich mixture, causing another set of problems.
Food for thought.
Hope this helps somewhat.
Bigger not always better.

[autoateljee]

I would go for a new viscous. Always the good temperature and no electrical troubles. Don't fit the viscous, the axle wil be damaged.

[BearGUST]

As a general rule thermo fans are fantastic.
- don't rob engine power
- they running at full speed at idle (often when your engine needs cooling the most)
But... All 4WD's seem to have clutch fans from factory, I have always assumed that this is for reliability. Based on that alone I'd be sticking with a clutch fan.

And $2000 for the work on Katrol doesn't sound too bad. Aluminium rads and electric water pumps are both dear as poison!

[hutchy84]

I would stay with the original fan as the thermos could fail and really leave up S#$t Creek

[Gruntgu]

I've just been through the cooling system after overheating problems, new thermostat, new fan clutch and blades strip and clean out radiator was 70% blocked i'd say this was the main cause. I got a new Dayco fan clutch through repco had problems fitting it over water pump spiggot had to shave some off there to make it fit.

Runs just under half way on the gauge now and only moves slightly when under load and towing but the clutch does'nt seem to release even when cold the fan roars all the time not sure what the go is there? Any ideas?

[BearGUST]

Clutch fans normally roar when cold. You should be able to stop the blades with your hands once that roaring has died down.

[Hongie]

a good viscous engine fan will 9 times out of ten flow more then thermo's

[Robo]

Yep, there's something wrong with fan clutch.
They only take a very short time to disengage, motor only needs to partial warm to make it work.
It should have fitted without modification.
What did you shave to make it fit?.
The contact area where heat is transfered between pump coupling & clutch.
If you have damaged this and repco won't replace it all I can suggest is,
go to jaycar or computer store, "not Hardly Normal's", a proper comp store, and ask for a small tube of heat transfer paste, this should fix lack of heat transfer.
It comes in a couple of diff recipes, 5 mls goes a long way, and cheapish.
I used this to help heat transfer on 2 different occasions for turbo timer thermo switch against rad and it works well.

Reason clutch is used is to reduce load on engine, extra ponys and also in return fuel economy. so good idea to fix it.
not to mention easy on the ears.
Cheers

[Gruntgu]

Yep, there's something wrong with fan clutch.
They only take a very short time to disengage, motor only needs to partial warm to make it work.
It should have fitted without modification.
What did you shave to make it fit?.
The contact area where heat is transfered between pump coupling & clutch.
If you have damaged this and repco won't replace it all I can suggest is,
go to jaycar or computer store, "not Hardly Normal's", a proper comp store, and ask for a small tube of heat transfer paste, this should fix lack of heat transfer.
It comes in a couple of diff recipes, 5 mls goes a long way, and cheapish.
I used this to help heat transfer on 2 different occasions for turbo timer thermo switch against rad and it works well.

Reason clutch is used is to reduce load on engine, extra ponys and also in return fuel economy. so good idea to fix it.
not to mention easy on the ears.
Cheers

Ok when i first went to mount the clutch and fan onto the water pump the clutch would'nt go onto the pump could barely get 2 nuts started so pulled back off measured the inside of the clutch and outside of the pump and the inside of the old clutch there was a measurable difference enough to not let the two mate together.

Took it back to repco and they got a new water pump out same thing, hmm wait another 3 days for another clutch and hope it was right or alter the pump.

I chose to alter the pump set it up in a vice drill on inside of water pump to turn it and file on outside to clearance it kept going a bit at a time until they fit together still friction between the two so should'nt be a problem.

I'll test it again today as it warms up and see what happens i maybe jumping the gun but with the old clutch i could grab the fan with a piece of rag easily at any time and stop it but don't seem to be able to with new one and you can hear it when accelerating from the lights at normal operating temp.

Cheers

Grunt

[cokeholic]

Many years ago when i was young stupid and had plenty of time (now im just stupid) i made my own thermo fans to run in my HQ Monaro i sourced a adjustable thermo and 2 10 inch blades from graig davis or davis craig and used 2 HQ heater blower motors as the fan motors. Cutting down the odd shapped mounting plate on the blowers to make it square,knocking off the heater fans and fitting the 2 10inch fan blades and fitting em to my 5 core radatior and no shroud.They kept my very warm 400 chev cool in city driving with no problem at all the clutch fans of the day just couldnt do the job

[Robo]

Just a guess as I have not compared these, mixing petrol parts and diesel parts is the problem.
Id only heard the fan from petrol wont fit diesel viscus and v/versa but both viscus and water pump are the same stud pattern or something. Maybe this is it?.

[Gruntgu]

Just a guess as I have not compared these, mixing petrol parts and diesel parts is the problem.
Id only heard the fan from petrol wont fit diesel viscus and v/versa but both viscus and water pump are the same stud pattern or something. Maybe this is it?.

I sent dayco an email with part number and problem so see what they say.

Sorry for hijacking your thread madk1w1

[Mrowka]

If you are going to do water crossings, stick with the clutch fan.