Calm my cooling system nerves

[raKnizek]

I recently installed an OEM cooling fan setup using second hand OEM parts. I had been running an electric fan that PO installed so I have no experience with how the mechanical clutch is supposed to operate.

It has a good bit of resistance when cold and you turn it by hand but it turns smoothly.

I can hear the fan pulling air when I cold start the truck and then it disengages after ~10 seconds.

Under normal conditions the coolant temp sits at 188 on scan gauge as it always has- cool!

I did some trails a few weeks back and the temp was 188-190 the whole time except on one occasion it randomly climbed above 200. The temp itself didn't worry me but the fan never kicked in. I noticed it climbing so I let it sit and idle and it fell back down within a minute or two.

Just looking for confirmation on the clutch operation. I have a second used one I could put on to compare. It feels identical to the current one when you turn it by hand.

Thanks!

 

[jgue467]

Based on the temps you are citing, things seem normal.

Yet what do you mean by, "...but the fan never kicked in..."?

You can always throw a few squirts of light weight oil onto the circular spring in front of the clutch to ensure it expands/contracts properly - sometimes when they get older they rust a bit tending to stick partially open/closed.

:cowboy:

 

[raKnizek]

Okay ill give that a try, thanks! By kicking in I just mean I could tell the fan was loosely spinning. Maybe I am wrong but as the temps rise that spring should expand and the fan should spin faster?

I am exposing my ignorance but come to think of it I've never had a vehicle with a mechanical fan...

 

[jgue467]

Here's a good thread on fan clutches: http://www.toyota-4runner.org/3rd-gen-t4rs/173832-fan-clutch-symptoms-how-loud-yours.html

In general a 'good' working clutch causes the fan to roar when the engine is first started cold or hot. After a short 200-300 yard drive, it will quite down when cold. That's usually how you can tell it's working correctly.

Normal temps are the proof of it working right overall of course. Once over 200 is no big deal, just watch what conditions it happens under. I think yours is good but you can also do a newspaper clutch test. Never done that, careful. :cowboy:

 

[Doc2012]

So, if you’re going up a steep incline, it’s going to jump because

1) transmission and radiator share the same space (kind of)

2) higher RPM, which makes heat.


12° isn’t much.

Seems like it, but it’s really not.

If you’re sitting in traffic, and the temp starts to climb, then cools off when driving, that’s a sure way to know your fan clutch is bad.

They’re not bad to replace. You can go to the auto store and get one.

There’s also a good tutorial on rebuilding fan clutches here:

https://forum.ih8mud.com/threads/fan-clutch-service.167678/


Sent from my iPhone using Tapatalk

 

[absalom]

Good on you for going back to OEM cooling setup

 

[gamefreakgc]

The fan clutch doesn't lock up unless you turn on the air conditioner. Otherwise it just free spins indefinitely and will slightly increase with engine speed.

What you described is 100% normal and working exactly how it should.

 

[raKnizek]

Here's a good thread on fan clutches: http://www.toyota-4runner.org/3rd-gen-t4rs/173832-fan-clutch-symptoms-how-loud-yours.html

In general a 'good' working clutch causes the fan to roar when the engine is first started cold or hot. After a short 200-300 yard drive, it will quite down when cold. That's usually how you can tell it's working correctly.

Normal temps are the proof of it working right overall of course. Once over 200 is no big deal, just watch what conditions it happens under. I think yours is good but you can also do a newspaper clutch test. Never done that, careful. :cowboy:

Excellent, thank you for the link!

 

[raKnizek]

So, if you’re going up a steep incline, it’s going to jump because

1) transmission and radiator share the same space (kind of)

2) higher RPM, which makes heat.


12° isn’t much.

Seems like it, but it’s really not.

If you’re sitting in traffic, and the temp starts to climb, then cools off when driving, that’s a sure way to know your fan clutch is bad.

They’re not bad to replace. You can go to the auto store and get one.

There’s also a good tutorial on rebuilding fan clutches here:

https://forum.ih8mud.com/threads/fan-clutch-service.167678/


Sent from my iPhone using Tapatalk

Appreciate the input! To your first point, this is a manual 4Runner so no shared heat exchangers but I see how that would effect it.

I agree that the increase I saw was not to worry I was just surprised at the conditions that caused it and figured I would double check since I just installed the system.

 

[raKnizek]

Good on you for going back to OEM cooling setup

I was really annoyed at first when I destroyed the electric setup but it was old, poorly wired, and clearly not reliable. I never bothered with it because despite all that it worked well and I could adjust when it came on, which was neat. In the end I am way happier with the OEM setup!

 

[raKnizek]

The fan clutch doesn't lock up unless you turn on the air conditioner. Otherwise it just free spins indefinitely and will slightly increase with engine speed.

What you described is 100% normal and working exactly how it should.

Awesome, thanks! eace:

 

[alumarine]

The fan clutch doesn't lock up unless you turn on the air conditioner. Otherwise it just free spins indefinitely and will slightly increase with engine speed.

What you described is 100% normal and working exactly how it should.

Sorry, not true for our vehicles.
Some vehicles with electric fans do that.

 

[phattyduck]

Sorry, not true for our vehicles.
Some vehicles with electric fans do that.

I was gonna say something along these lines. When the AC is on, it is much more likely that the fan clutch will lock up, but it isn't guaranteed. It locks up when the air being pulled through the radiator is hotter than it should be (lots of excess heat behind removed from the radiator/condenser) - which will happen in hot weather, high engine loads or AC use - but there is no direct link between AC use and the fan locking up.

-Charlie