Failed fan clutch question

[ecgreen]

Do 2.9 fan clutch fail with the fan on - so that they run constantly? If so, is this a bad thing? What would be wrong with it being on constantly?

Thanks!

 

[Uncle Gump]

I think they can fail either way...

If it failed ON.... it would be noisy and cause a bunch of unnecessary drag on the engine. Fuel economy would tank and suffer lack of power.

 

[Dirtman]

I've personally never seen one fail ON but cant think of any reason it can't happen. I would still fix it though, in addition to the reasons uncle gump said, it may also decide to randomly unlock and die in the OFF position which would be very bad. Catastrophic on a 2.9...

 

[ecgreen]

OK, so I have a new one laying around and one in the truck that is suspect. Survey says....change it

 

[cbxer55]

Kind of interesting that these things fail. The one on my 98 3.0 is 22 years old, has near 168,000 miles on it. Still works flawlessly. Same with the one on my Lightning. They spin freely when stopped, yet the trucks never overheat idling, even on near or over 100 degree days.

 

[Dirtman]

Wait... you have a lightning?

 

[RonD]

Easy test is to start engine cold, you should HEAR the fan startup, its locked now, let engine run for 20 seconds then shut engine off
Open hood and try to spin the fan, should spin easily, easy to move it, if not its locked when it should not be
Fan clutch locks from Radiator heat, not engine heat
So radiator needs to warm up FIRST, then fan will start to lock

Yes, a drag on a cold engine, also longer warmup time, which matters in winter months
And it could fail unlocked at any time at this point, could also get unbalanced, and take water pump bearing out from the vibration

 

[Shran]

I've had them fail both ways. The one on my old '96 failed ON, huge lack of power and it was very loud. The one in my old '89 failed OFF, and became obvious when the truck would get hot at stop lights and immediately cool off when moving again. The clutch on that one would just free spin and never kicked in.

If you're replacing it, now is a great time to replace your water pump too.

 

[RonD]

I had a 2.9l fan clutch that was out of balance, had a vibration above 2,800rpm, other wise worked fine, pain to track down that vibration

 

[Paulos]

When I bought my '87 Ranger back in '03 it had a locked up fan clutch. It sounded like a Cessna, had a little vibration, and definitley ran better after replacing it..

 

[franklin2]

I have had them lock up ON also. No doubt what is happening, you would not believe the noise it makes under the hood.

The one on my ranger was suspect, and when I looked it over the plastic fan had some serious looking cracks in it. I had a 16 inch electric fan laying around from another project, and I stuck that on there. It works well and gives a little more room around the front of the engine without the shroud in the way.