exploding viscous fan

[elty001]

any body got any ideas on what can cause the fan to explode.mine went bang today and took the radiator with it.
as luck would have it my motor was just warming up on the drive at the time.
all that is left is the steel ring that bolts onto the water pump

 

[extreme-4x4]

all the belts intact elty. my guess would be a belt slipped off and got cought up and ripped it off....

the other option is its frozen recently and fractured the pump housing .
i remember the paullllllllyyyyyyyy gave me had frozen and cast ally fractures when water freezes behind it and pushes it out

 

[elty001]

been running fine,anti freeze changed in nov of last year when i did the water pump and stat also did the belts at the same time.
wasn't that cold last night was raining all day so freezing not an issue:nenau

 

[extreme-4x4]

maybe rick will advise better, i cant see any other reason why it would explode i cant see its made up or works in a way that could even if faulty explode

 

[zippy656]

id think belt too..

just one of those things.. belts fail..

 

[solarman216]

as we all know when we start up from cold the fan is running at full speed till the viscous fluid get spun to the outside out of the way, during this time as the fluid starts as a lump in the bottom where it settled over night, it is under the most strain, my guess is the welds/rivets/swaging? that holds it together were weak and just gave way under the strain

 

[rustic]

my guess is the welds/rivets/swaging? that holds it together were weak and just gave way under the strain

If this is the case then possibly the pump was faulty, where did you get it from?

You are unlikely to get consequential losses from the supplier, but if you do get a free replacement and it happens again, you may loose another radiator.:nenau

 

[solarman216]

if this pump was under a year old you have a claim, I was not aware it was a recent replacement, if so keep all the bits, Rick

 

[elty001]

the pump was bought from milners last november so its still under warranty.
the belts are fine and still intact and the pump turns freely with no tight spots or noises.
had a good look at the fan and on one of the broken blades i can see that its got a darker line about halfway across the break which would indicate to me that it has had a crack in it for a while.
must have hit the rad with some force as its sheared off the two mounting bolts which hold the rad to the front slam panel.

 

[solarman216]

Ay up, can we be a bit clearer here, do you still have the Ali finned lump on the water pump that turns independently of the pump but with a bit of resistance? if so you have just lost your fan blades and nothing to do with the viscous unit, if however you some broken bits of Ali around the engine bay and a lump on the front of the water pump that you cannot turn then its the viscous bit that broke, Rick

 

[elty001]

the viscous unit is fine its the plastic fan which has gone bang.
this has exploded into lots of pieces and burst the rad.

 

[11redrex]

That's really odd for it to just go like that. Had you been off road the day before ? Maybe something hit the fan ? Or it could have been this (6th post): http://www.nissan4x4ownersclub.com/forum/showthread.php?t=10667&highlight=ferret

 

[solarman216]

Simply plastic fans need checking from time to time for fractures, Rick

 

[11redrex]

Simply plastic fans need checking from time to time for fractures, Rick

And ferrets.

 

[solarman216]

Oh and ferrets :thumb2 but round here it's squirrels :lol Rick

 

[jims-terrano]

I first heard of the fans cracking several years ago on here when Rossco found his cracked and replaced it before it could break. since then I've seen a few posts about the cracks but never heard of one actually breaking. I guess really it's a sign of age and these motors are getting long in the tooth now. Bad luck Elty, hope you get it fixed soon.

Jim

 

[Peasgood]

I had a metal fan explode on my tractor once. That made a mess!
If part of it snapped off because of an old crack it would throw it right out of balance and would lead to shattering as you experienced.
I think I have one here somewhere if you are after a replacement.

 

[elty001]

i had a look at it when i changed the waterpump last november but couldn't see any visable cracks.
maybe when i fitted it to the new pump i over tightened it and put stress on an already weak fan:nenau
been used daily and not had any problems or weird sounds from the engine bay.i guess its just one of them things

 

[rustic]

Just think of the consequences, if the bonnet had been open and you were say checking for a squeeking fan belt.....

 

[elty001]

Just think of the consequences, if the bonnet had been open and you were say checking for a squeeking fan belt.....

tell me about it lucky really i guess:thumb2