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Discussion Starter #1
'97 Suzuki Sport JLX, 4-speed automatic, 1.8L, 4x4, A/C

Any thoughts on why the fan would run full speed when the engine is started cold? It runs for a minute or so then stops. That never happened on my '95 1.6L 16 valve.
 

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Perfectly normal - it's a viscous clutch fan and that's what viscous clutch fans do, I'm surprised to hear you say that the 1.6 didn't do it, because those have viscous clutch fans too - maybe it's not as loud, so not as noticeable.

By the way - it's a mechanical fan, so it can only run as fast as the engine is running - so it's not actually running full speed.

Ok - time for the why - the fan clutch contains a liquid, a thick, viscous, silicone oil, and when the engine is off, the liquid will pool in the bottom of the fan hub, and in so doing it "locks" the fan clutch which forces the fan to turn at "pulley speed" - what ever speed the fan pulley is turning at.

When the engine starts, the fan spins and the oil is distributed by centrifugal force out to the rim of the fan clutch, disengaging it, so after a short time, the fan slows, so the fan itself is turning at less that pulley speed.

Depending on the temperature of the air flowing through the radiator, a bi-metallic spring within the clutch opens/closes vanes that control the oil flow, which in turn controls the difference between pulley speed and actual fan speed - as the engine gets hotter, the fan moves faster and draws more air through the radiator to cool the engine, and vice versa.

It's a fuel economy thing - it takes energy to drive the fan (quite a bit of energy) and you may not actually need the fan to move a lot of air, for example, on a highway, the forward motion of the vehicle forces air through the radiator, making the fan unnecessary (until you get into a traffic jam), so by "de-coupling" the fan from the pulley you can save a lil bit of gas.
 

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Discussion Starter #3
Thanks! I never thought about the fluid draining down when it's cold. I think you're right that it's a particularly noisy fan and I'm going to take a close look at it in case there's a cracked blade or maybe just too much normal wear. It has 103k on it.

I'm looking for reasons why I can't get into the 20's on gas mileage and thought the fan might be a factor. The thermostat is good and I replaced the O2 sensor.
 

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But I don't think that the fan should 'stop'........????
 

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The fan doesn't stop Bex, the noise does - as the fluid redistributes, the fan clutch "de-couples", so the blades are spinning at a lower speed than the fan pulley, and the noise is reduced.
 

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'97 Suzuki Sport JLX, 4-speed automatic, 1.8L, 4x4, A/C

Any thoughts on why the fan would run full speed when the engine is started cold? It runs for a minute or so then stops. That never happened on my '95 1.6L 16 valve.
Yes I understand but read this to mean that the fan stops....
 

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I know on my 1.8 when i start it the fan spins very fast for a bit then slows down (I can actualy see it slow down as one of the blades on the fan itself got stained) then it speeds up when the thermostat opens.

if your fan is stopping altogether then i would say the fan clutch is bad.
 

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Discussion Starter #8
Sorry for the confusion. The fan slows down and stops making excessive noise. The noise of the fan literally drowns out the engine but i'm yet to hear it when I'm driving. I took a good look at the blades and one tracks about 1/8" off the others. I also see lines at the base of two blades that I can catch my finger nail on. They look like cracks but I can't get any movement by flexing the blades. I wouldn't be surprised if the plastic blades warped and/or cracked after 17 years and 103k. I sure don't want a blade to depart the area via the radiator so I would replace the fan if I could find a new one. I see none listed in any of the major parts suppliers catalogs.
 

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Discussion Starter #10
Thank you! A Suzuki owner for 18 years and I never new this site existed.
 

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Me, either, actually.....;)
 

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Nothing for the Irish posters, sadly...:(
 

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Discussion Starter #14 (Edited)
Prices seem to be better at Lehmans.
 

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We have a vast selection of car parts and services over here Bex,

to include...

 

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Thanks for rubbing it in, Max...;)

We have this in Ireland:
MicksGarage | Car Parts and Car Accessories Online from The Car Parts Experts

If you click the link, you will see the extraordinarily definitive list of Suzuki Vitara parts available here. Not.

So either parts come from the dealer (if available) or the UK. Sometimes parts are expensive enough here where it actually is cheaper to buy parts in the US and have them mailed here. Of course, this doesn't work for something large like an exhaust system.....
 

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I actually Googled up that link yesterday, when you mentioned the lack of parts over there! ;)

Sad indeed. :(
 
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