Close Call

[Dave L.]

I was returning from a nice 50 mile afternoon ride when I heard a loud 'roar' coming from the engine compartment that got louder with rpm's. when I got home I noticed that the noise was coming from the fan. I turned the engine off and tried to rotate the the fan. Locked up tighter than a drum. Clutch fan bearing failure. I have heard and seen horror stories of the fan seperating from the clutch and flying straight up through the hood. I will bring one home from work and hopefully find time to install in the next week or two.

Dave

 

[Rowdy1]

Or........

"I have heard and seen horror stories of the fan seperating from the clutch and flying straight up through the hood." Seen them go through the radiator too. Glad you caught it Bro.

 

[Shawn's 78]

Replaced the Harmonic Balancer the other night, hooked it all up, gave it a tune then let it run for 15 minutes to be sure the belts were set.
All of a sudden, a I hear this "noise", so to be safe I shut her down and check the belts etc. Turns out the fan clutch was loose enough to fly off if I had left it run any longer. I guess when the fluid heated up, it had enough play to be dangerous!

Thank God it was in the garage and not on the road. I've heard a few stories of fan clutches coming apart. NOT GOOD! I think my problem arised when i threw a belt two weeks ago and it rapped itself around the fan clutch. I dont' think (now I know) it didn't do it any good.

Glad you caught it in time!
Shawn

 

[Nut]

Close call Dave. I'm putting a flex fan on mine come spring to help with the temp problem I still have. Glad she didn't blow on I-83.

............. Nut

 

[Dave L.]

Nut - As a matter of fact I was on 581 coming through HBG at pretty good clip. I found a clutch at the local AC-Delco distributor for $63.
Dave

 

[cruzer99]

This is weird.......I had the same roar suddenly coming from the hood last Sat. also. Found the same thing, the fan was locked up which I thought was strange because I thought when they went bad they free-wheeled and did not lock up. I replaced it (35.00), with a new one Sunday.

 

[78SilvAnniv]

flex fan

We had run hot problems in the summer the entire time we had the 78. (13 yrs)
Through parts changes and a new motor. The run hot problem did not get resolved until we removed the fan clutch and installed a quality flex fan last summer. No more overheating, except for the time my heater core blew...but that was understandable...I'd lost 1/2 my radiator level of coolant/water!

If I can avoid it, I will not use a fan clutch. I've been present for too many fan clutch failures (that occur too often) to see their benefits.
Heidi

 

[Nut]

I hear you Heidi. However, I've heard they can be a bit noisy. How about your set up?

.......... Nut

 

[78SilvAnniv]

It is louder...

...but I don't find it annoying at all. I grew accustomed to the different noise very quickly. I can only hear it at slow speeds and idle, but again...it is not annoying at all.
The chambered exhaust commands most of my listening attention these days!

I would much rather listen to a flex fan moving air than a squeaky pulley or belt!
Heidi

 

[Rowdy1]

I Don't Like Flex

I've seen flex fans come apart too, the rivets let go and the blades go flying. I also had a running warm problem but I also have some serious mods done. The two things that solved my problem was a solid blade oval track racing fan specially designed for more air flow and the aluminum BCool radiator. The fan was $35 at a local speed shop.

 

[Justin_cv87]

now thats somthing i gotta see, someone just chillin, and a fan ripping off their hood and flying in the air!

 

[resto75]

NUT

Nut,
What is the Colt in your signature for ??? Is that your car alarm ???

 

[Ken]

"I have heard and seen horror stories of the fan seperating from the clutch and flying straight up through the hood." Seen them go through the radiator too. Glad you caught it Bro.

Just came across this, from Automotive Engine Cooling System Explained:

Because the fan clutch and water pump share a common shaft, if the fan clutch fails it usually takes out the water pump bearing with it. To tell if a fan clutch is failing, use these common symptoms.

• The fan clutch locks up, thereby spinning at the same RPM as the water pump. This is obvious by increased fan noise and reduced fuel efficiency. You can test this by grabbing the fan with the engine OFF and trying to turn the fan. If there is excessive resistance, or you cannot spin the fan, the fan clutch should be replaced.
  
• The fan clutch will not engage and fails to turn the fan. The fan may still spin, but only as a result of centrifugal force from the already spinning pump. If you try to spin the fan with the engine OFF, the fan will spin freely with virtually no resistance. Replace the fan clutch.
  
• The fan clutch explodes. This is usually caused by severe bearing failure. Fan and fan clutch parts will contact and damage the hood and other under hood engine components (belts, hoses, battery, wiring, radiator, etc.)

NOTE: This is almost always due to vehicle owner "laziness" in that one of the two items above had already occurred and were ignored or not periodically inspected.

Generally, fan clutch output under normal operating conditions will decrease by about 200 RPM per year. So, a three year old fan clutch is possibly due for replacement, or at least more periodic inspections. A four year old fan could very well be running partially disengaged and should be replaced.

_ken

 

[Guy]

Dave,

If things are going to go, it's nice to be close to home. Last summer just after a 90 mile ride, my upper radiator hose blew just as I pulled into the garage :eek. Easy fix and no AAA.


Guy

 

[Stallion]

So there are fans on the clutch to cool it down so the clucth doesn't overheat? Is that the use?

 

[ccflorida]

Fan Clutch

Stallion The clutch engages and disengages the fan depending on thermal temperature at highway speed there is more air flow to cool the motor and the clutch will disengage the fan thus giving less strain on the motor.. I also asked several mechanics about flex fans and their comment was stay away from them...If you change the water pump you should also change the clutch too..Hope this helps ya ..

 

[Dave L.]

Ken - Thanks for the info.I will make sure to check that fan clutch periodically when I have the new one installed.

Guy - Thats a good place to find a rad hose leaking. I am glad I wasn't 150 miles away or I would have had to use my AAA card!

Dave

 

[78SilvAnniv]

For Stallion...

The fan clutch is not a fan for the clutch that assists you while shifting gears, it is a part on the front of the engine block that assists with cooling the engine.

The fan pulls air through the radiator and has a 'body' that it is mounted to called the clutch. The fan and clutch assembly are called the fan clutch.
Heidi

 

[Stallion]

Okay, I think I understand the functionality of the fan clutch. So, a "clutch" in general in a car (not so much specific to the gear changer) is anything that can switch/change a "setting" (part, I guess)? That's what I got out of what you guys said. Thanks!

 

[billybob]

ccflorida,

I also asked several mechanics about flex fans and their comment was stay away from them...

Any reasons, with a comment like that you must have asked why?

The HUGE price difference. The fan clutch isnt a cheap thing to have to replace every 3 years. And a flex fan is a nice alternative.

Bill