3 x thermo fans stripped in one trip - GU custom brass radiator 6.5 chev GU

Hi Folks,

My brother had a nightmare trip away and we were just wondering if anyone had experienced this or any feedback on what could of possibly caused this?

Gu ute, 6.5 Chev and he recently spent a small fortune on a new custom brass radiator and removed the fan and replaced with 2 x 16" Davies Craig rear thermo fans as he had overheating issues.

Has had them on for a few months now but only around town driving, not much highway use. Prior to the trip everything was running like a dream. Even testing it out on our radiator hill from Yarra Glen was the best it had ever ran.

Long story short, towing his camper up to the Murray doing 110km. Just before Shepparton he noticed the water temp was at 3/4. Pulled over and noticed one of the fans had died.

Thermo fan motor still worked but noticed the plastic mould of the fan blades that wrap around the nut that sits on the shaft of the motor had basically been stripped away. Almost like it had melted around the nut and stripped it.

Another 10 km's down the road and the other fan did the same thing so he was in trouble and car was overheating.

Stopped into shep (Fletches workshop) and checked everything out.

Radiator is brand new, dead straight, the install was done correctly and wired up correctly, etc. No install issue so the only choice was to replace it with another one as he had to keep driving.

There was only one in town so they put that on and another 100km's down the road that one stripped too!

Manufacturer dates are all different (5 months apart).

Has anyone stripped thermo fans before?

We are lost for why this has happened???

It was working fine around town for a couple of months prior but never did long highway work, we cannot find any hit marks on the radiator or thermo shroud or if they may have flexed on high speeds, etc.

were they used to pull or push the air??
The fans shouldnt be on at 110 maybe they were on and being forced to spin

Quote:

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Originally Posted by threedogs

were they used to pull or push the air??

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Behind the radiator to pull.

And yes all 3 fans were reversed.

The way I see it is the thermo fan has been running to long and its own heat from its motor has caused this to happen
running around town on short trips and up the hill dose,nt add up to 100ks straight run

when do they cut off??

Quote:

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Originally Posted by threedogs

when do they cut off??

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I don't think they did thermostat needs looking at

These fans should be able to cope with being run 24/7 for sure! Overheating and melting from their own motor would be a HUGE design flaw!

Quote:

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Originally Posted by Winnie

These fans should be able to cope with being run 24/7 for sure! Overheating and melting from their own motor would be a HUGE design flaw!

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They can only spin so fast and 110kph they should be off as you dont need a fan at hwy speeds
I think the fans were on and fighting the air coming through the radiator at 110kph

Quote:

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Originally Posted by threedogs

when do they cut off??

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I don't know that part mate.

Something is really odd about this scenario.

1. The fans should be able to run for hours, no worries at all
2. They must have got freaking hot but how did they get hot if the vehicle did not (until they failed)
3. The fact the replacement only lasted 100 K's but the originals a few months is "interesting"
4. The vehicle should be running cooler at 100 ish along the freeway than around town
5. The faster you go the less load on the fans as the ram air is assisting the spin
unless...
the fans are the wrong way around and they were pushing and the faster the vehicle went for longer the more load was on the fans.

Nothing else makes sense, well not that easily leaps to mind anyway, so I would double check the fan direction of rotation

P.S. I have Davies Craig fans on my tranny cooler and they are always on, sometimes for 18 hours straight less meal stops, had one on my intercooler that used to run for hours at a time and 3 all shitting themselves at once.... nah, something else is wrong