Outer Limits 4x4 Board

Hi all just sit here wondering whats better Viscus or Thermo fans

Running a 304 efi in a GU with std allo radiator with the viscus fan.
but the fan seem to be on all the time and thats with a new viscus the temp is sitting just under 1/2 way would their be much diffrent's apart the noise the viscus makes

if unsatisfied have ya tried filling the clutch up with oil (as in the silocone stuff ya can get from toyota) Ya pull the hub apart on the fan and fill it with the the oil. I have allways beleived the factory fans (with a good shroud ) to be better then thermos but im shore i will be corrected.

DA DUDE wrote:Hi all just sit here wondering whats better Viscus or Thermo fans

Running a 304 efi in a GU with std allo radiator with the viscus fan.
but the fan seem to be on all the time and thats with a new viscus the temp is sitting just under 1/2 way would their be much diffrent's apart the noise the viscus makes

Of course the viscous fan spins all the time, it's attached to your crankshaft via belts. A thermo fan is electric, usually attached to an electric thermostat switching on or off as thermostat opens. Stick a hammer handle, etc into blades whilst idling. Fan should stop if clutch is working and resistence will build as hub spring heats up. If your temps sitting at under half i'd say you don't have a problem so why change it?

Of course the viscous fan spins all the time

yea but it shouldn't drive flat out all the time, i can hear mine start and stop on the highway over the wind noise! - and feel the corresponding power drop when it kicks in up hills! d'oh Also on cold start it spins hard for a few minutes and then you can hear it go quiet when it all frees up!

well tell this is it because i'm running a diesel viscus fan in a petrol engine is their diffrent's

Patroler wrote:

Of course the viscous fan spins all the time

yea but it shouldn't drive flat out all the time, i can hear mine start and stop on the highway over the wind noise! - and feel the corresponding power drop when it kicks in up hills! d'oh Also on cold start it spins hard for a few minutes and then you can hear it go quiet when it all frees up!

you sure your talking about a viscous fan? a viscous fan is driven by the fan belt, and goes all the time.. when the engine is cool though (startup, easy highway driving) the viscous clutch loosens, and the fan wont do the full rpm the engine is... they dont 'kick' in like a thermo fan... sure your not talking about an auxilary thermo fitted in front of the radiator, usually tied into the air con?

Patroler wrote:

Of course the viscous fan spins all the time

yea but it shouldn't drive flat out all the time, i can hear mine start and stop on the highway over the wind noise! - and feel the corresponding power drop when it kicks in up hills! d'oh Also on cold start it spins hard for a few minutes and then you can hear it go quiet when it all frees up!

mine does the same
i need to do something about it before i go on hollidays.

scuba steve 22 wrote:

Patroler wrote:

Of course the viscous fan spins all the time

yea but it shouldn't drive flat out all the time, i can hear mine start and stop on the highway over the wind noise! - and feel the corresponding power drop when it kicks in up hills! d'oh Also on cold start it spins hard for a few minutes and then you can hear it go quiet when it all frees up!

you sure your talking about a viscous fan? a viscous fan is driven by the fan belt, and goes all the time.. when the engine is cool though (startup, easy highway driving) the viscous clutch loosens, and the fan wont do the full rpm the engine is... they dont 'kick' in like a thermo fan... sure your not talking about an auxilary thermo fitted in front of the radiator, usually tied into the air con?

When the vixcous fans start to seize they run pretty hard all the time, causing the excessive noise and air flow.

thomo.in.a.gq wrote:

scuba steve 22 wrote:

Patroler wrote:

Of course the viscous fan spins all the time

yea but it shouldn't drive flat out all the time, i can hear mine start and stop on the highway over the wind noise! - and feel the corresponding power drop when it kicks in up hills! d'oh Also on cold start it spins hard for a few minutes and then you can hear it go quiet when it all frees up!

you sure your talking about a viscous fan? a viscous fan is driven by the fan belt, and goes all the time.. when the engine is cool though (startup, easy highway driving) the viscous clutch loosens, and the fan wont do the full rpm the engine is... they dont 'kick' in like a thermo fan... sure your not talking about an auxilary thermo fitted in front of the radiator, usually tied into the air con?

When the vixcous fans start to seize they run pretty hard all the time, causing the excessive noise and air flow.

Na mines all in pretty good nick 170k 93 gq, only electric fan on the thing is the heater! viscous is belt driven and can spin freely but when you're hitting a big hill and it gets a bit hot the viscous fluid must increase in viscosity and not allow any slip and therefore you can hear and feel(power loss) the fan come on - actually its probably more noticeable when it unlocks (freewheels) after being locked goes quiet all of a sudden.
Also on a hot day 30+ in town its pretty noisy when you rev it (as it should be) as its driving all the time.

they dont 'kick' in like a thermo fan

they pretty much do if they're working well!

they dont 'kick' in like a thermo fan

they pretty much do if they're working well!

Hmm. i have a brand new genuine fan on my TD42.. cant say iv'e ever noticet it in any way.. noise power ect...?

90Mav wrote:

they dont 'kick' in like a thermo fan

they pretty much do if they're working well!

Hmm. i have a brand new genuine fan on my TD42.. cant say iv'e ever noticet it in any way.. noise power ect...?

how much did you pay for a genuine one?

Had it installed under warrenty when i braught the truck..

90Mav wrote:

they dont 'kick' in like a thermo fan

they pretty much do if they're working well!

Hmm. i have a brand new genuine fan on my TD42.. cant say iv'e ever noticet it in any way.. noise power ect...?

well i suppose it don't matter as long as it stays at the right temp, mine usually hovers between 1/4 - 1/3, and you'd only hear it if you were at a constant speed/rpm (highway) with the radio off and were listening for it! still definately hear it tho.

replacement clutch is about $360. Dont believe anyone makes an aftermarket one either. Only about double the price of a genuine toyota model...

GeneralFubashi wrote:replacement clutch is about $360. Dont believe anyone makes an aftermarket one either. Only about double the price of a genuine toyota model...

its a nissan

and there are plenty of aftermarket ones available as i have tried 4 of them

DA DUDE wrote:well tell this is it because i'm running a diesel viscus fan in a petrol engine is their diffrent's

Well there's a heck of a difference between the diesel and the petrol fanblades themselves. The diesel fan has one extra blade, and a more aggressive angle.

When I went from the petrol one that some moron had put on the diesel troll before I bought it, to the Diesel one I put on it last week, The difference in airflow was massive. It also meant that with no other changes, I went from 60% of the gauge on a hill climb, to 50% of the gauge on a hill climb - from 70% on a long climb, to 60% on a long climb now. I am stoked with it.

It cost me $50 odd including postage from "Patrolapart" on ebay.

[hey mate ,im running a 351 ford cleveland in a gq & i just recently pulled off the clutch fan & now running a twin thermo fan setup of a 1997 EL falcon,, it keeps it alot cooler, less noise & u notice a little power increase, & if it keeps a ford cool it should do yours easyly,, good luck mate,,

DA DUDE wrote:well tell this is it because i'm running a diesel viscus fan in a petrol engine is their diffrent's

if you have a diesel viscous clutch, this will be your problem.

you need to put a petrol one back on.
Jes

I got a new one for petty from Don Kyatt's in Moorabbin, Vic for a little over $100 i think. Japanese part, same as Nissan use but without the 'genuine nissan parts' packaging.

Give them a try, they may be able to post one to you. Hobzee on this forum may be able to source one for you too.