It seems like my fan runs the whole time, sounds like a nissan hardbody, this normal?
PAJERO 3.2 LWB GEN 4 AUTO
Rocksliders|Roof Rack|Bash Plate|Suspension lift|Dual battery system|
Rocksliders|Roof Rack|Bash Plate|Suspension lift|Dual battery system|
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is it the viscous or electric fan?
the electric always runs with the A/C
the electric always runs with the A/C
The viscous fan can be annoying. Have it checked out. I plan to chuck mine out and fit an electric fan, still doing research on the pros and cons before I go ahead. I did a successful conversion on a few of my vehicles, but never a diesel, so just being a little careful on this one.
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Do a google for "4epikanini 3.0 cooling modification"paramaniac wrote:The viscous fan can be annoying. Have it checked out. I plan to chuck mine out and fit an electric fan, still doing research on the pros and cons before I go ahead. I did a successful conversion on a few of my vehicles, but never a diesel, so just being a little careful on this one.
I went through this and I'm glad I stayed with the viscous. There is no ways an electric can move air like a viscous. And you want to move as much as possible air to aid cooling - especially on a diesel!
4Epikanini I followed you rebuild thread on another forum while back, must say I enjoyed it. I am very "in the mood" to replace my Merc with a V6 SWB, seeing that there a n lot of things I can do myself. Swambo doesnt want to bite yet 
Mine does have in fact a Viscous to answer your first Q.
Mine does have in fact a Viscous to answer your first Q.PAJERO 3.2 LWB GEN 4 AUTO
Rocksliders|Roof Rack|Bash Plate|Suspension lift|Dual battery system|
Rocksliders|Roof Rack|Bash Plate|Suspension lift|Dual battery system|
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if the viscous is blowing all the time it may have leaked the fluid inside or the mechanism seized. It should blow hard on cold start and then go quiet after about 30 seconds or so and then blow hard again when the engine is working hard.
Having a faulty viscous that blows hard all the time is bad for fuel consumption and the extra stress on the fins may fatigue the plastic and cause them to fail, punching holes in the radiator. Viscous fans are designed to spin at a maximum rpm so if you lock the clutch to the fan it will exceed this rpm and eventually fail.
There is nothing better for your cooling system than a proper working viscous fan!
Having a faulty viscous that blows hard all the time is bad for fuel consumption and the extra stress on the fins may fatigue the plastic and cause them to fail, punching holes in the radiator. Viscous fans are designed to spin at a maximum rpm so if you lock the clutch to the fan it will exceed this rpm and eventually fail.
There is nothing better for your cooling system than a proper working viscous fan!
Hi Marius,
What is the possibility you can get us the figures: What is the max. cubic foot per second (or metric equivalent) that the viscouse coupling fan is pushing on the 3.2 DID and what will it be on the petrol motors. The max revs on petrol is much higher.
To me, if I study the mechanism, where a bi-metal strip is used to open or close a valve for the fluid to lock or unlock the fan, the ones used on petrol enjins should deliver more cfm just because the revs is higher. I could not find any other mechanism that is limitting the revs of the viscouse once it is locked due to high temparature.
Regards,
Waldo Fourie
What is the possibility you can get us the figures: What is the max. cubic foot per second (or metric equivalent) that the viscouse coupling fan is pushing on the 3.2 DID and what will it be on the petrol motors. The max revs on petrol is much higher.
To me, if I study the mechanism, where a bi-metal strip is used to open or close a valve for the fluid to lock or unlock the fan, the ones used on petrol enjins should deliver more cfm just because the revs is higher. I could not find any other mechanism that is limitting the revs of the viscouse once it is locked due to high temparature.
Regards,
Waldo Fourie
Affiliate Member
The viscous is engineered not to rev to max rpm.
I can't remember the max rpm but I believe the viscous does not exceed about 2000rpm. The viscous never operate at the same rpm as the engine. It will have a max rpm rating and the oil inside it with the bypass channels will limit its rpm based on vehicle specific redline. Ie. A petrol viscous will have less friction between the impeller and body due to higher engine rpm.
If the viscous is locked (a popular trick is with a screw into body) to the engine rpm it will slowly deteriorate (I have seen a few disintegrate and destroy the radiator) , crack and fail.
I don't know the cfm between a viscous and electric but I can almost guarantee the viscous pulls a lot better than an electric.
Other points to note
- if you do find a high enough cfm electric fan (that will fit) the alternator will work very hard and cause higher consumption.
- a dodgy viscous still gives some cooling where an electric doesn't
- if electric was better the manufacturers would use it as it's generally cheaper
- the only benefit I see with electric is that you can stop it with a bypass switch when wading deep water.
I can't remember the max rpm but I believe the viscous does not exceed about 2000rpm. The viscous never operate at the same rpm as the engine. It will have a max rpm rating and the oil inside it with the bypass channels will limit its rpm based on vehicle specific redline. Ie. A petrol viscous will have less friction between the impeller and body due to higher engine rpm.
If the viscous is locked (a popular trick is with a screw into body) to the engine rpm it will slowly deteriorate (I have seen a few disintegrate and destroy the radiator) , crack and fail.
I don't know the cfm between a viscous and electric but I can almost guarantee the viscous pulls a lot better than an electric.
Other points to note
- if you do find a high enough cfm electric fan (that will fit) the alternator will work very hard and cause higher consumption.
- a dodgy viscous still gives some cooling where an electric doesn't
- if electric was better the manufacturers would use it as it's generally cheaper
- the only benefit I see with electric is that you can stop it with a bypass switch when wading deep water.
Last edited by 4ePikanini on Mon Jul 04, 2011 12:02 pm, edited 1 time in total.
Hi Marius,
A bit of surfing and the answer on the speed of a viscouse fan was found. Mostly they are torque limited by the viscouse coupling at a speed of about 2 500 RPM. Can also be limited buy means of electronics.
I would still like to know what the output in cfm is for the viscouse fans used on Pajero's
Waldo Fourie
A bit of surfing and the answer on the speed of a viscouse fan was found. Mostly they are torque limited by the viscouse coupling at a speed of about 2 500 RPM. Can also be limited buy means of electronics.
I would still like to know what the output in cfm is for the viscouse fans used on Pajero's
Waldo Fourie