fan explosion

S

Sepacal

New member
So Tuesday morning I got up to start my 1990 4runner, and being a cold morning, it was a bit hard to start. Nothing unusual. I gave it a little gas and KAPOW! uh oh... I get out, look underneath the truck and there's fluid pouring out right near the front, so I'm thinking radiator hose or something. Open it up, and the radiator hoses are fine, but the fan and fan shroud are obliterated, and they took out the air filter, timing belt cover, coolant reservoir, and even the battery in the process. I'm thinking that the fan and shroud were frozen, and that they made contact somehow and that was what initiated the 'explosion'.

What are some other thoughts about how this may have happened?

What can people check to avoid this problem? It was a major pain in the arse to get all these parts and put humpty dumpty back together, I wouldn't want anyone else to have to spend the time and money to do that.

PS, the fluid came from the battery.
 
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I remember reading somewhere that the 3.0s had a problem with fans asploding from the factory, perhaps the reason for fan shrouds.
 
No pics of the destruction unfortunately. I don't think that the fluid came from the fan clutch, but I replaced it regardless. Lucked out with good parts cars for most of the rest.

If they really put a fan shroud to protect from the fan exploding, they could have at least made the shroud out of something other than that cheap axx plastic. Could a bad fan clutch have caused this?
 
Sepacal said:
No pics of the destruction unfortunately. I don't think that the fluid came from the fan clutch, but I replaced it regardless. Lucked out with good parts cars for most of the rest.

If they really put a fan shroud to protect from the fan exploding, they could have at least made the shroud out of something other than that cheap axx plastic. Could a bad fan clutch have caused this?
Click to expand...

The fan shroud isn't there to protect the fan from exploding. It's there to help the fan "pull" air through the radiator instead of from around it. Think about it...if the shroud wasn't there, a lot of air would be pull around the fan instead of through the radiator.

Still though, fans aren't supposed to explode like that. If the fan clutch completely failed, it could cause the fan to come into contact with shroud. If the fan clutch was broken open, it will definitely throw fluid around under your hood. If you're correct thinking that it was battery acid, you should see a lot of damage to the surrounding areas because battery acid will really mess up stuff under the hood.
 
the fan bearing will start to decay after time the fan will get a little wobble to it, when the wobble gets to a certain point the and the fan is at high rpms or even just 3,000 it can wobble its way to hit the fan shoud and that's when the shrapnel begins to fly!!

next time you have a oscillating fan going throw a grape into it and see what happens.

the fact is the fan was rotating and when it came into contact the metal blades vs whatever it hit began collateral damage to your engine bay.

Get a bunch of baking soda and clean that acid up NOW!!! before it eats all your rubber and wires and well the truck.
 
Thanks for the replies. The reason that I think the battery was the source of the fluid I saw leaking is that from my point of view it seemed to be coming from that specific area, and not the area of the fan clutch or from wider engine bay area. Also the battery has a huge chunk missing from the side and seems dry. That being said, I'm not seeing damage done to anything that was in the area of the leak, and its possible that it came from the wiper fluid reservoir, which is a very low priority of needing to be replaced at this point. I haven't noticed damage to it but haven't done anything more than check at a glance. I would post a picture of the battery but I took it in for the $12 core.

So checking for fan wobble is a way to see if you need a fan clutch, which you could then replace and avoid this? That definitely sounds worth the time to me.
 
DocMT said:
Are you sure the fluid wasn't from the fan clutch?
Click to expand...

just noticed this what kind of fan clutch would have fluid in it???? really? come on?
99% of fans are a rod with a bearing and a coil spring so that the engine isn't pushing dead weight right away.
 
Ya watch that battery acid, that stuff is very nasty and corrosive. get the engine compartment detailed asap

Mark
 
the_dingman said:
You may not see any damage from the battery yet, but it's acid... It will eventually.
Click to expand...

not if you did what i told you to do.

Baking soda is a base which neutralizes acid, that means no damage from the acid if you clean it with baking soda but it should have been done right away!!!

So for now just try to soap it as much as possible and wash the area over and over until your hands are sore, that is IF you dont want to deal with rewiring and replacing sensors that got the acid on them not to mention the paint fade( don't expose the acid soaked areas to sunlight until you have cleaned the crap out of it

sorry dingman i for some reason thought he posted that
 
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Thanks for all the replies. Unfortunately I wasn't ready with the baking soda at the time. It was snowing out and I had to get to work. It took a couple days to gather up all the parts I needed to replace, and it wasn't until I started putting the new Fan/Clutch on that I even noticed the battery had been damaged. But once i saw the damage it made sense that that was where the fluid came from. So thats a few days of possible battery acid corrosion, and I'm not seeing anything. I could be wrong, maybe it was the wiper fluid resovoir. Either way I'll get out there with soap. The only areas potentially exposed to the acid are within the engine bay, near the area directly below the battery, so I think the damage will be minimal anyways.

Thanks again for all the advice.
 
Bad_Vision said:
just noticed this what kind of fan clutch would have fluid in it???? really? come on?
99% of fans are a rod with a bearing and a coil spring so that the engine isn't pushing dead weight right away.
Click to expand...

Every fan clutch I've ever seen has fluid in it. Without fluid, they don't work.

And the "coil spring" you mentioned is actually used as a temperature sensor to engage or disengage the clutch. Read up on fan clutches and you'll understand what I'm talking about.
 
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Bad_Vision said:
viscous drive has fluid most of the fans i have delt with are electromagnet, sorry i forget about old school.
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LOL, call it old school if you want, but every 4Runner ever made has had fluid in it's fan clutch. That's true even for the 2011 4Runner.

I'm not sure if you know this or not, but most vehicles don't even have a fan clutch these days. Electric fans that are controlled by a thermostatic switch are much more common. So in that sense, all clutch fans are old school.
 
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