Loud radiator fan on 2017 Fuso

Plumb Bob

I just completed a 800 mile road trip, truck with about 4,000 lbs of camper on back. On steep interstate grades, trying to maintain 60- 65 mph the radiator fan engages for about 45 seconds every minute or so. Ambient air temperature around 40- 45F.
It is incredibly loud, needed to put earplugs impossible to talk in the cab. Anyone else experience this, maybe an electric fan assemble may be quieter?

I'l also work on better cab insulation.


I'l also work on better cab insulation.

Hello Bob:

We have had two of these trucks (2014 & 2017) & that fan was noticeable in both. It's my impression that it is louder in the 2017, but that's probably due to variation in the aftermarket cab insulation. We have some friends who worked hard to install much better insulation on their 2007 - they used an adhesive insulation installed on the outside of the cab, directly over the engine. As I recall, they are really happy with the temperature reduction in their center console as well as the greatly reduced noise. The use of external insulation on the bottom of the cab over the engine seems like a good idea to me - much easier to install than inside the cab where you'll need to remove all the lining, etc.

Howard Snell

Plumb Bob

Thanks Howard, if you have any info on brands, types, or thickness of insulation send it my way. I want to be sure what I buy is temperature and moisture tolerant. Mine just has one skimpy piece directly over the engine, plenty of bare metal under there to add insulation onto.

Spanna 53

I added Dynamat under the floor mats all across the floor under the seats and up the rear wall the little bit left over I put above the fan / radiator on the engine side of the cab if you are going to do the engine compartment side I would suggest cleaning the panels well with Prepsol or uni prep used by paint shops as a grease and tar remover . I can now hear the management and radio but the fan noise is still there only not as bad .Ross

Glenn C.

Travels in Wolnośc
Yes......the cooling fan is a real conversation stopper when it comes on above 3000rpm's. I have improved on that and it is a boatload of work, here is what I have done.

So I have completed my cab noise control project for now with truly pleasant results.
First I ordered some 1/2" 4lb noise attenuating foam from the thefoamfactory.com.
It comes about 70" wide and is sold by the foot. I cut a piece to fit in the cab to house bellows area cut as wide as I could and still snap down the cover. This made a difference in the noise coming from that area, good start. Next I picked up some 3M Professional Rubberized undercoating (6 cans) and coated the fender wells and under the cab with the exception of the engine area behind the radiator, not that that area did not need attention but I was unwilling to coat the area around turbo with a substance that is possibly flammable. The next step was a boat load of work. Thanks to Steven Pon I took apart the base of the cab (with a full days help from Steven) , seats out, console out and all floor material out. The 1/2" foam was placed under the whole seat area from the top of where the vinyl floor material starts at the back of the cab to the edge of the floor below the seats. We used a heat gun to warm and soften the foam sheet and pressed it into the contours of the cab bottom (heat the foam to soften press into the contours with wooden tools made for the job and hold until cooled[pains taking to say the least}). When the whole bottom was covered we used a 7/16" punch to make the holes for all the attachment points for the console, seats and seat belts etc.. The vinyl and seats and console were all replaces (much easier said than done, needed to get longer bolts in many cases). That leaves the floor area. For the floor area I ordered DynaPad (made by Dynamat) from Amazon. This is a multilayer noise control foam that is 1lb/sq.ft., heavy stuff. This material was placed on the floor starting at the top of the sloped area in front of the base of the seats and extended across the floor and up to the "firewall". This material comes 54"x32"X0.425" and was used as a single piece centered in the cab and cut around all the bits in the way under the dash. This left small areas on either side uncovered, I cut leftover pieces of the 1/2" foam to fill in this area and attached it to the DynaPad with Gorilla duct tape. All done, I replaced the floor vinyl, the plastic sill pieces and the floor matts. Time for a test ride. Jeanne, Mustard and I jumped in and headed to the highway for a test drive. At 60mph with the cooling fan on turning 3500rpm's (dropped into 5th when the fan came on) conversation was possible! The general noise level in the cab was noticeably lower. A success!
What would I do different? I would use all DynaPad, the material is easier to work with and is designed to control the low frequency sounds that are generated by the cooling fan (and other engine and road noises). This was a total of 3 days, 8 hours/day of work, 24 manhours (Steven for one day) and for me totally worth it!
The other opportunity that I see for noise control is the front wall of the house, the rear of the engine bay is wide open and focused at that flat surface, reflecting the noise to the cab. This would require a waterproof noise attenuating material to cover the area, and because of the proximity of the turbo exit pipe the material would need to be fire rated. I am looking into a material that will meet that spec. I will report what I find.
Any questions feel free to contact me 508-820-6430
Happy Trails,
Glenn C. EC34 Wolnosc


thanks Glenn. I'm awaiting delivery of some mass loaded vinyl (heavy, similar to dynamat I guess). I have enough for the rear cab wall, and doors.

Plumb Bob

Thanks Glenn, that is my plan also to strip the cab of seats and trim and add layers of the Noico brand Sound Deadening sheets and their Sound Proofing product over that.
Interesting that the produce origin is the Russian Federation :)
I hope to do this only once.
Curious if anyone has switched to electric fans, you can feel the horsepower hit when these clutch fans engage. It must be thermostatically controlled as it only comes on sometimes with an uphill pull and headwind. It would be interesting to know how many CFM are required and see if an electric or two could move the BTUs, the nicer model electrics seem much quieter from reviews I've read.

One step at a time.


Crazy Person
I have to say... I have never noticed any fan noise in my FG84.
Maybe it's just me, or the newer models, with the smaller 3.0L motor, perform very differently than the tractor motor in my truck.

Plumb Bob

I have to say... I have never noticed any fan noise in my FG84.
Maybe it's just me, or the newer models, with the smaller 3.0L motor, perform very differently than the tractor motor in my truck.

This truck runs much higher rpm then any of my previous diesels, 3000rpm at 65. My Ford and Dodge diesels ran around 1800. That high rpm probably adds to the noise level of the fan.

I quizzed the dealer about adding an overdrive to get rpms down, he indicated they need to spin that fast for emissions? Not sure I follow that logic, although I know they don't like to idle for extended periods. This model has an auto shutdown after a certain idle time period.

When I sold my Ford Powerstroke the buyer slid underneath to see if it had a PTO or signs of one being used. They look at engine hours not milage to determine engine wear. Ford suggests hours X 25 to get a true mileage. Truck dealers and buyers around here use hours X 30. My truck had 95, 000 miles and 6000 hours X30 they call it a 180,000 mile truck. I have seen suggestions of hours X 60 for PTO truck that idle most of the day.


Expedition Leader
My fan clutch engages so infrequently that I couldn't figure out what was going on the first time it happened near the top of the climb to the Eisenhower Tunnel on a hot day. Shift down, go slower and it will typically disengage.


New member
I also have a 2017 FUSO FG and the fan noise is very irritating. If you think the fan is annoying at mild temperatures just wait until you go somewhere that it is hot. I recently traveled through the California and Arizona deserts where the temperature was between 95 and 100 degrees F. The fan ran continuously; uphill, downhill, on the level and with or without the AC on. I've had the truck at two different Freightliner [FUSO] dealers and they say everything is normal. If this is normal then the cooling system design sucks. One dealer said he could replace the electric fan clutch with a viscous one and it would reduce the frequency of operation, but it would void my warranty. Like other FG owners I'm trying to cover up the noise rather than addressing the underlying problem. I removed the seats and the rug/plastic floor mats and installed Dynamat Xtreme from the rear of the cab to the firewall. It took 8 3/4 18"x32" sheets to do this job. I also installed the Dynamat Hoodliner 32"x54" above the engine under the cab. I wish I could say it was a great success, but I can't. It helped but not as much as I would have liked. Good Luck.


New member
Unfortunately it seems to be a common complaint with the Canter. I have gone down the dynamat path , having removed the whole interior and lined the interior and under cab/engine bay . The results were not as good as i would have liked but we can almost talk to each other when the fan kicks in . We weigh 8.0 tonnes combined and find the fan really kicks in when the wind is side on . I think the problem is having the ABS system right in front of the radiator and not sealing the radiator to the cab surround allows air to flow over and around rather than thru the radiator. I will be experimenting shortly by adding a deflector under the radiator to direct more air upto the intercooler /radiator .

Plumb Bob

I did add a deflector and it too made a small change, mainly in how often the fan kicks on. The biggest annoyance is when it drops to 5th on a hill, rpms go to 3000+ The noise becomes painfully loud!
I think OSHA would shut down our job site if decibels were this high from construction equipment :)

I have some Sony noise cancelation ear buds, plugged into my phone so at least I can hear it ring. May as well pull off the road if you want to talk.

Hard to imagine in this day and age that a manufacturer can't engineer an issue like this out of a vehicle?

Alpina FG

I find the fan engages as you suggest for about 45 seconds, off for 60 and then back on when at speeds of 65 or so. I drive slower and it stays off more or less. I just built this scoop (aluminum) in about 45 minutes and installed it as pictured. It's quite solid. I'll be testing it to see if it makes any difference.


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