Fan clutch ?

[NWFLBowhunter]

I'm pretty sure the noise I'm hearing is coming from my fan, and it all started after a stick got wedged between my radiator and fan blades. It sounds like a bad power steering pump kind of noise and increases with rpms. Sound about right for a bad fan clutch?

 

[ThorInc]

Bearing is toasted.

 

[nissanh]

There are 2 bearings in that unit. One is the fan bracket and this usually known to make noise.
Dealer has the complete unit (fan bracket, two pulleys and fan clutch for $450 or so). Aftermarket online you can get the fan clutch $120 (Aisin) and Fan bracket $120 (Aisin). Do not buy any other fan clutches as they make excessive wind noise.

 

[NWFLBowhunter]

There are 2 bearings in that unit. One is the fan bracket and this usually known to make noise.
Dealer has the complete unit (fan bracket, two pulleys and fan clutch for $450 or so). Aftermarket online you can get the fan clutch $120 (Aisin) and Fan bracket $120 (Aisin). Do not buy any other fan clutches as they make excessive wind noise.

So, should I replace the complete unit or just the clutch?1997 Toyota 4Runner Parts - Camelback Toyota Parts - Genuine OEM Parts - Free Shipping

 

[Jhelms]

If the stick prevented the fan from turning, it likely killed the fan clutch (very odd scenario!) But if you are doing the fan cluch, do the fan idler as well. It is also called a false water pump.

- New Aisin false water pump idler PN: FBT-004 (about $125 as mentioned)
- New Aisin fan clutch PN: FCT-013 (common to find this for $90ish)


Double, triple check that the stick did not damage the fan blade assembly and radiator.

 

[NWFLBowhunter]

If the stick prevented the fan from turning, it likely killed the fan clutch (very odd scenario!) But if you are doing the fan cluch, do the fan idler as well. It is also called a false water pump.

- New Aisin false water pump idler PN: FBT-004 (about $125 as mentioned)
- New Aisin fan clutch PN: FCT-013 (common to find this for $90ish)


Double, triple check that the stick did not damage the fan blade assembly and radiator.

radiator is shot as well, had to jb weld it to stop the leak in order to get it home. Fan seems undamaged. I thought the belts were just wet from playing in some deep water, but it was a jammed fan causing the screaming belts.

 

[Jhelms]

radiator is shot as well, had to jb weld it to stop the leak in order to get it home. Fan seems undamaged. I thought the belts were just wet from playing in some deep water, but it was a jammed fan causing the screaming belts.

DOH!!!
Denso Radiator PN: 221-0508 Great affordable radiator

 

[TheDurk]

Uhhh, there is no way a bad fan clutch is causing screaming belt noise. Just not possible. There are two ways an FC can fail:

1) It locks up when it should freewheel. You get fan noise (sort of a jet engine sound), not belt noise.

2) It freewheels when it should lock up. No noise at all.

Replace your fake water pump aka Fan Pulley Bracket. That will cause belt/bearing noise when the bearing locks up.

If you want to test the FC, here is how (copied off a BMW board but applies perfectly to our trucks:

Testing the fan clutch:
If you have reason to suspect that the fan clutch is defective, here is the recommended procedure to verify the condition of the fan clutch.
1. Start the car (cold) with the hood open and note if the fan is turning, increase the engine RPM and note if the fan turns faster and the noise increases, if it does, first good indication, if it does not increase speed/noise, clutch is bad and needs to be replaced. (Remember, this must be tested after the car has been off for and extended period, over night etc.)
2. Leave engine running and note if the fan starts to slow down after 2-5 minutes, speed/noise should diminish and even raising the RPM, the fan should not make as much noise as when first starting, if it does slow, this is the second good indication. If speed/noise does not decrease, clutch may be “frozen” and should be replaced.
3. Leave the engine idle and watch the temperature indicator. When normal operating temperature has been reached, some increase in fan speed/noise should be noted, in particular when the RPM is increased. If temperature is fairly stable and the fan noise/speed increases or cycles, third good indication. If temperature indication continues to increase, with no increase in fan noise/speed, clutch is defective and should be replaced.
4. After the engine is at normal operating temperature or above, is the only time that the “rolled up newspaper” test that many people talk about should be performed! Take some newspaper and roll it up into a long narrow tube. Be careful, keep hands and fingers away from the fan while performing this test! With the engine at full operating temperature and idling, take the rolled up paper and insert it on the back side of the fan and try to reach the hub of the fan avoiding the blades until close to the hub. Push the rolled paper at the fan increasing the friction to the hub area of the fan. If the fan can not be stopped easily this is the fourth good indication, if it can be stopped the clutch is defective and should be replaced. Again, this test can only be performed when the engine is at or above full operating temperature.

Testing can be performed in any order but just make sure the conditions during testing are those that are specified for that specific test.
Do not continue to operate the engine if the temperature continues to rise and certainly stop if the temperature approaches “redline”.

 

[NWFLBowhunter]

Uhhh, there is no way a bad fan clutch is causing screaming belt noise. Just not possible. There are two ways an FC can fail:

1) It locks up when it should freewheel. You get fan noise (sort of a jet engine sound), not belt noise.

2) It freewheels when it should lock up. No noise at all.

Replace your fake water pump aka Fan Pulley Bracket. That will cause belt/bearing noise when the bearing locks up.

If you want to test the FC, here is how (copied off a BMW board but applies perfectly to our trucks:

The screaming belt noise came from the stick being wedge between the radiator and fan blades, preventing the fan from turning. I drove it a bit thinking it was just wet belts, but then started smelling company. Now, with the stick gone, the noise is more of a loud blower/whine that increases with rpms.

 

[TheDurk]

The screaming belt noise came from the stick being wedge between the radiator and fan blades, preventing the fan from turning. I drove it a bit thinking it was just wet belts, but then started smelling company. Now, with the stick gone, the noise is more of a loud blower/whine that increases with rpms.

Ah, THAT sounds like a locked up FC. What happens when you try to rotate the fan with engine off? It should turn easily while pushing but not spin freely when you let go.Personally, I would change just that. The Pulley bracket bearing (aka fake water pump) could go eventually, or it could outlive your engine. It usually gives some warning before it goes, so I'd spend those $$$ elsewhere. When you have the fan and belts off, check if it spins freely with no wobble or vibration. But if you are maintenance obsessed and have the $$$, you can swap it.