Fan clutch noise

[kerry]

Was climbing up to the Eisenhower Tunnel on I-70 West side in 4th gear when near the top the temperature gauge starting rising a bit and shortly after I heard a high pitched whine. Surprised me at first and it went away quickly after heading downhill in the tunnel so it only lasted a minute or two. I now suspect it was the fan clutch engaging due to the increased temperature. Does anyone else hear the fan clutch engage like that? I tried to wiggle the clutch and water pump shaft when I got home and everything seems tight. The fan itself did seem a little tight. I was expecting it to freewheel easier than it did. It's very rare for my temp gauge to climb at all so I don't think I have much experience with the fan clutch engaging. The temp gauge did rise once in the past on the same climb but I didn't hear a whine when it happened. Normally I'd expect a kind of roar and not a whine when the fan clutch engages.
Or, does someone think the whine could have been something else?

 

[boostin]

Does a belt drive the fan on your model?

 

[kerry]

Yes.

 

[boostin]

Maybe the belt is loose or worn and when the fan clutch ingaged it slipped and made a noise and did not cool from the slipping

 

[unkamonkey]

The only time I got any noise from mine is when the fan belt is loose and then the AC kicks on. I have tended to avoid that whole area of I 70 in the heat of a summer day. The beastie runs better in cooler temps. Never a peep out of it in the winter.

 

[kerry]

Hadn't thought of the extra load on the belt causing the noise. I'll check it. I did replace the belts a while ago and never adjusted them after they wore in a bit.

 

[kerry]

Belts were slightly loose. I tightened them. I've never had trouble on I-70 even in the summer. Just a slight raise in the temp gauge near the summit a few times.

 

[whatcharterboat]

Hi Kerry,

So did tightening the belts cure the noise?

I remember you telling me a few years back that you couldn't go outside to work on your truck cause it was minus 18 degrees. It is obviously a very different place to where I come from.............and much hotter so the trucks work accordingly so, however the fans all gave up on our FG84's at work so one by one all the fan couplings (clutches) were pulled apart and locked up. In the pic, the bus I was driving had just been done but the junior mechanic had not got it right so the guys had to make a dash to fix it on site while my passengers went for a hike in the rainforest.



Also when we run soft sand (eg towards the top of the tide and running downwind) sometimes the temps will really get up there. We found the OEM temp gauge not up to the task ..... not accurate enough and in your face. So we now run after market gauges (IIRC 40c to 140c range) very prominently up near the windscreen pillar. Makes life so much easier. Once temps start pushing 95c I'm looking for somewhere to pull over and park idling into the wind. As long as they don't get any hotter than that, the temps come right back down very quickly.

BTW having EGRs bypassed makes a difference to running temps too.

Kind regards John

 

[kerry]

John:
I don't know if it fixed it. The temp gauge is very steady on my FG so I'll have to do a very steep climb again to get it to raise enough to engage the fan clutch. So I probably won't know for a while. I have wondered about the accuracy of the OE temp gauge. I am very curious as to how you got the fans to lock up. I used to own a 1985 Mercedes 307d with the 616 engine and the fan clutch on that engine had a little tab which could easily be bent down between two ears to lock up the fan if the clutch failed. I really liked that feature.
By the way, we've arranged a swap with an Aussie couple. We're coming down under in March 2017 to use their Troopie camper for a couple of months and they're coming over to use our Fuso in September 2017.

 

[pugslyyy]

Also when we run soft sand (eg towards the top of the tide and running downwind) sometimes the temps will really get up there. We found the OEM temp gauge not up to the task ..... not accurate enough and in your face. So we now run after market gauges (IIRC 40c to 140c range) very prominently up near the windscreen pillar. Makes life so much easier. Once temps start pushing 95c I'm looking for somewhere to pull over and park idling into the wind. As long as they don't get any hotter than that, the temps come right back down very quickly.

BTW having EGRs bypassed makes a difference to running temps too.

Kind regards John

I've noticed that running in sand really makes my temps go up to. I need a better / more visible temperature gauge as well I think. Has anyone ever made an a-pillar pod for the fuso?

 

[whatcharterboat]

I am very curious as to how you got the fans to lock up.

Yeah, a tab would be cool. Nothing so easy as that though. The fan coupling comes apart and a disc of thin rubber is sandwiched between the two halves.

By the way, we've arranged a swap with an Aussie couple. We're coming down under in March 2017 to use their Troopie camper for a couple of months and they're coming over to use our Fuso in September 2017.

Awesome. March is still pretty hot and wet for travelling up North but by May the country starts to become very inviting.....so if you're staying for a few months I'd advise leaving the Northern travel until the end......Kerry PM me when it gets close. You're welcome to stay at my place if you're coming this way or if you need help with whatever. Definitely keep us posted.

kind regards,
John.

Hi pugslyyy,

Ours is like this (excuse the phone pic quality)>>