FZJ80 Fan clutch always engaged even while cold, why? (1 Viewer)

[studawg]

Forgive me because Im asking for a friend and only have limited info, and dont have the vehicle here to inspect...

-Radiator was leaking so he took it to a Japanese specialist and they replaced the radiator, hoses, thermostat and cap
(Note: He has spent a large amount of money with them over the years and I dont think they know what they are doing when it comes to an FZJ80)

-Now he said his truck is really loud. He asked them about it and they said it was "his belts, they need to be changed". After asking my friend some questions, it sounds like to me his fan clutch is always engaged.

-They did not charge him for a new fan clutch, but friend says it looks new (not sure on that though), and is blue.

Based on this limited info, does anyone have any idea what might be going on here?

Thanks

 

[jonheld]

Without looking under the hood while the engine is running it's going to be pretty hard to diagnose over the internet. Especially if there have been unknown hands touching things.

 

[studawg]

Without looking under the hood while the engine is running it's going to be pretty hard to diagnose over the internet. Especially if there have been unknown hands touching things.

Right but if the fan clutch is just staying engaged, is there any other solution than just replacing it? (Besides rebuilding it, if that's even possible.) Is there any other cause for a fan clutch staying engaged besides a failed fan clutch? Assuming the engine is cold?

 

[jonheld]

Right but if the fan clutch is just staying engaged, is there any other solution than just replacing it? (Besides rebuilding it, if that's even possible.) Is there any other cause for a fan clutch staying engaged besides a failed fan clutch? Assuming the engine is cold?

If the fan clutch is seized, then it's done. This can be easily diagnosed with the engine off and cold. If you can rotate the fan, then it's not seized. That doesn't imply that the fan clutch is operating properly, just that it can rotate freely. The viscous fluid will settle to the bottom of the clutch body if it has sat for a period of time, so the clutch will appear to be harder then easier to turn as it rotates until the fluid flows through the clutch body. But it should rotate nonetheless.

 

[studawg]

10-4 thanks!

 

[LandCruiser105]

Start it up from cold - there should be a noticeable fan 'roar' which dies away after the oil starts to circulate (about a minute or so). Plus as studawg says above, spin it *before* you do this to check it is not seized.

 

[Kernal]

Quick test to see if the noise is from the belts; spray or pour some water on them (step back while doing this) with the engine idling and listen for a change in the sound. If it goes away for a couple of seconds and comes back then the noise is likely coming from the belts. There will be no change in the noise if it's due to a frozen fan clutch. FWIW