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

[AB]

Do these fans free spin when turned off or stop? as I wonder if the fans are not switching off when the temp cools down and the air is spinning them to fast causing overheating??
You would think they should be able to handle that tho...hmmm

I have no idea myself mate, he ended up pulling the fuses when he turned up to camp and it was a crappy cold day today so no need for fans on the way home.

[NissanGQ4.2]

This is from my old man Andy, I asked him to have a look at your post

Our fans do not have a nut holding the fan blade onto the shaft. They are pressed on and there is a wave type clip on the end of the shaft. Some models (I think they were called a pancake design, motor was very thing) did have a nut as the fan blade itself had to be reversed to change the air flow as the motor would only run in one direction. Our fans have the fixed fan blade as the motor direction is reversible by swapping the wires over.

These fans should be able to run all the time with out any problems.

He stated that the water temperature gauge is 3/4 but that does not give any indication what the actual temperature is.

Over heating can also be caused by the bottom radiator hose sucking closed (clasping in on itself). Some vehicles have to have a spring wire coil inside the hose to stop them clasping in on them-self. This is usually cased by high draw (flow) caused by a water pump that is trying to move a lot of water into the motor.

Is he using a water thermostat in the engine. If removed it can cause overheating.

There is a lot of things that can cause over heating is wrong size fans, no fan shrouds to direct air flow, fans set too low on the radiator, air not being directed onto the radiator (that is oncoming air hitting the front of the radiator and being forced under or around the sides) Ignition timing, fuel mixture too lean at high speed .

As in another post the fans could be turning in the wrong direction and the wind pressure is putting a lot of strain on the blades but that should not cause them to melt, but may cause twisting on the shaft nut or clip.

There would have to be a massive of heat on these fan blades to cause any damage to them that is unless there is a fault with the materiel that the fan blades have been made of.

[nissannewby]

It's a 6.5 .....

[AB]

This is from my old man Andy, I asked him to have a look at your post

Our fans do not have a nut holding the fan blade onto the shaft. They are pressed on and there is a wave type clip on the end of the shaft. Some models (I think they were called a pancake design, motor was very thing) did have a nut as the fan blade itself had to be reversed to change the air flow as the motor would only run in one direction. Our fans have the fixed fan blade as the motor direction is reversible by swapping the wires over.

These fans should be able to run all the time with out any problems.

He stated that the water temperature gauge is 3/4 but that does not give any indication what the actual temperature is.

Over heating can also be caused by the bottom radiator hose sucking closed (clasping in on itself). Some vehicles have to have a spring wire coil inside the hose to stop them clasping in on them-self. This is usually cased by high draw (flow) caused by a water pump that is trying to move a lot of water into the motor.

Is he using a water thermostat in the engine. If removed it can cause overheating.

There is a lot of things that can cause over heating is wrong size fans, no fan shrouds to direct air flow, fans set too low on the radiator, air not being directed onto the radiator (that is oncoming air hitting the front of the radiator and being forced under or around the sides) Ignition timing, fuel mixture too lean at high speed .

As in another post the fans could be turning in the wrong direction and the wind pressure is putting a lot of strain on the blades but that should not cause them to melt, but may cause twisting on the shaft nut or clip.

There would have to be a massive of heat on these fan blades to cause any damage to them that is unless there is a fault with the materiel that the fan blades have been made of.

Thanks toddy but yeah it's a 6.5 chev and the viscous has been removed and replaced with the 2 x 16" thermos mounted on/behind the radiator that is what's been chewed.

Fwiw though, after the last one died the only way he made it to camp without cooking the engine was to have the ac on.

The condenser fan made enough difference to not boil.

[the evil twin]

snip...

Fwiw though, after the last one died the only way he made it to camp without cooking the engine was to have the ac on.

The condenser fan made enough difference to not boil.

Now I know your kidding me... 2 X 16 inch Davies Craig won't cool it but a dinky little A/C fan will?

Glad I have the Viscous Clutch on my Chevy... I am going to be really interested in what the fix to this one is...

[NissanGQ4.2]

Thanks toddy but yeah it's a 6.5 chev and the viscous has been removed and replaced with the 2 x 16" thermos mounted on/behind the radiator that is what's been chewed.

Fwiw though, after the last one died the only way he made it to camp without cooking the engine was to have the ac on.

The condenser fan made enough difference to not boil.

He read it is a 6.5, we are both running twin thermo fans, mine are Davies Craig his are falcon fans even though he did buy the same CD thermo's as mine it was easier 2 put the falcon ones in.

I would be re checking the direction of blades

[Winnie]

Now I know your kidding me... 2 X 16 inch Davies Craig won't cool it but a dinky little A/C fan will?

Glad I have the Viscous Clutch on my Chevy... I am going to be really interested in what the fix to this one is...

The Davies Craig fans weren't spinning though!

[the evil twin]

The Davies Craig fans weren't spinning though!

The 2nd one was when the vehicle initially went to 3/4's so he pulled up to investigate... and then the 3rd one was when the 2nd one failed.

Like I said, something is really weird... hey, you Vic's haven't stumbled on a cache of 'ludes or something have you... it's only fair to share you know

[threedogs]

I take it no shroud is fitted and fan are fitted directly to the radiator.
Can you find out if they were on a thermostat ?
Did you use paper strips to determine air flow or just a hand,

[big_fletch]

I checked it out when he had got too Shepparton and replaced one of the fans. The Davies Craig fans are plastic with a center metal nut that's basically cast into the fan. The plastic fan blades had basically stripped from this nut with is held too the motor shaft with a clip. Fans run through a separate relay from each fan and triggered by a thermo switch mounted into the top of the radiator.

Both fans are bolted through the radiator. After replacing the fan and checked it was not rubbing on the radiator I checked airflow direction with my hand and then put a piece of paper down too double check myself.

Myself and my Boss are stumped on why it's doing it?? Once the problem is worked out I'm very keen too know what's wrong

Fletcha