2008 Ranger 3.0L 2WD Fan Clutch Problem?

[mctavish]

Hi everyone. I mostly drive highway and have not had any a/c issues . Now that it is quite hot outside, I noticed in city stop and go driving my a/c cuts out for a while and noticed the temp gauge at going up to 75% . I shut off the a/c and put my heater fan on and the temp gauge went back to 50%. Back out on the highway the a/c worked okay. I figured that the water pump is probably ok and it could be the fan clutch. When I got home I could turn the fan blade easily. How much resistance should there be or should it be tight when it is hot? I have an AllData account but it wants you to use infrared thermoter and optical tach to check the fan clutch rpm so that is out of the question. Any suggestions? Thank you.

 

[RonD]

Your assessment is correct, reads like classic fan clutch failure symptoms.

Fan clutch works from radiator heat, not engine heat, just FYI.

On the front of the fan clutch, next to the rad, is a bi-metal spring that is heated up by hot coolant flowing thru the rad after thermostat opens.
As the spring heats up it causes the fan to spin closer and closer to water pump pulley speed, so pulls more air thru radiator.
If engine/rad coolant is fully warmed up the fan clutch should be fully engaged, so you should not be able to "spin it" at all.
You can move it but it should have lots of resistance.

Classic symptom of failing fan clutch is temp gauge climbing when stopped or moving slowly, no air flow thru rad, and then temp gauge going back down at higher speeds when vehicle movement creates radiator air flow for cooling.

From your description I would replace fan clutch

Yes, water pump can cause the same symptoms, but fan blades would not spin easily after warm up.

 

[Andy D]

With the fan clutch off, try to wiggle the water pump pulley, and check the weep hole for a drip.

 

[enjr44]

When it gets really hot and the AC is doing it thing in stop and go you can hear the fan very clearly when the engine accelerates. Unlike when it is cooler, then you cannot hear the fan.

 

[RonD]

When it gets really hot and the AC is doing it thing in stop and go you can hear the fan very clearly when the engine accelerates. Unlike when it is cooler, then you cannot hear the fan.

Yes, +1

If engine sits overnight or for 5+ hours the fan clutch fluid will cool off and get thick, this, in essence, locks the fan clutch to fully engaged.

So when you start a cold engine you will hear the fan grabbing air because it is fully engaged, this will only last 10-15seconds, then fluid heats up from the spinning and cold clutch spring disengages, so fan noise drops off.
If you don't hear that fan noise any more on start up could be sign of fan clutch failing

 

[Spott]

Yes, +1

If engine sits overnight or for 5+ hours the fan clutch fluid will cool off and get thick, this, in essence, locks the fan clutch to fully engaged.

So when you start a cold engine you will hear the fan grabbing air because it is fully engaged, this will only last 10-15seconds, then fluid heats up from the spinning and cold clutch spring disengages, so fan noise drops off.
If you don't hear that fan noise any more on start up could be sign of fan clutch failing

Not....exactly. Modern fan clutches don't use a bi-metal spring anymore, they use an odd (and smelly) fluid that gets thinner as it cools and thicker as it warms. Same effect as as bi-metal spring.

The fan clutch fluid never "cools off and gets thick", that is the opposite of its function. When the engine is cold, the fan will always be as loose as it gets (but it's never completely free-spinning, so keep your hands out).

The fan does not spin hard when starting, and any noise you're referring to immediately after starting has a different source.

If your fan free-spins on the clutch, the clutch is bad and needs replaced.

 

[RonD]

I know the imports used that for awhile, must be a later American change haven't seen one yet myself, just seen e-fan or bi-metal springs

This is a 1998 to 2008 Ranger fan clutch: http://www.ebay.com/itm/1998-2008-F...ash=item2a6a0a1f7e:g:su4AAOSw3mpXNPvf&vxp=mtr

 

[Spott]

Interesting. The clutch in my 88 used the funny fluid and had no spring; I disassembled it when it failed.

I'm also very certain that the fan clutch (whether fluid or spring) is not engaged when starting the engine cold, because after disassembling the aforementioned failed fan clutch, I installed some screws straight through it to keep it constantly engaged, to get me through to the next payday. The noise difference between that and a normal fan start is massively different.

 

[RonD]

They all use fluid, my '88 2.9l had the spring.

And always heard them grab that air on cold start and then fade out after a few seconds

 

[mctavish]

Thanks everyone. I am ordering the clutch and will let you know how it goes. I am 90% highway driving and the a/c works fine but today in city driving it acted up again. When I got home the engine was hot and I could turn the fan easily.

 

[RonD]

Good call

Look at the labels on the rad support plate, it will tell you which way to turn the fan clutch nut to loosen and tighten.
My 4.0l is regular thread, but I think the 3.0l is reverse thread

Video here: www.youtube.com/watch?v=MtICtNT6PUg