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-   -   Exploding clutch fan ? (http://www.bimmerfest.com/forums/showthread.php?t=658749)

robertobaggio20 11-17-2012 03:21 PM

Exploding clutch fan ?
 
I'm sure you've read the odd post here and there about an exploding clutch fan that kills everything and sometimes makes a big dent in the hood. It only comes loose while driving. Those who post that here go onto say that they've done away with the vicsous clutch fan entirely and switched to an electric fan.

If you have done that, you may still have trouble. Apparently, the fan falls apart in that way due to issues caused by bad engine mounts. Please see :

http://www.bimmerfest.com/forums/sho...30#post5740730


rgdz,
Roberto

snowsled7 11-17-2012 06:43 PM

Fan clutches do not explode, they do not wear out water pumps, they are a minimal drag by design. It is a clutch that engages when needed otherwise freewheels (more or less).

If your motor mounts have failed, allowing the engine fan to hit the shroud, you could most definately have a mess of broken parts and a dented hood. This is not a fan clutch issue.

I only read the first couple of pages. Lots of bad info for sure:rolleyes:

robertobaggio20 11-17-2012 07:06 PM

What you say certainly sounds sensible.

Fan clutches have come off the water pump shaft and dented the hood before. The reasons offered then were all related to a bad fan clutch. The post I've referred to above contains the following blurb on the first page :

Quote:

Originally Posted by doru (Post 5743027)
Actually the BMW techs consensus about exploding radiator fans is because of failed engine mounts. When the clutch fails, it only accelerates the matter. And because the v8 has more torque, the engine mounts fail earlier. There were also quite a few posts with people experiencing the 2nd failed fan and not knowing why. Once the mounts were changed, the fans lasted.

To my recollection, the hows and whys of how this happens has never been discussed in detail, as such, the op's version of events has never been disputed. Doru's assertion here is thus new over here.


rgds,
Roberto

robertobaggio20 11-17-2012 07:22 PM

For anyone who wants to get into the meat and potatoes of exploding clutch fans, this looks like the right thread :

http://www.bimmerfest.com/forums/sho...d.php?t=562281

snowsled7 11-19-2012 05:07 AM

Originally Posted by doru
Actually the BMW techs consensus about exploding radiator fans is because of failed engine mounts. When the clutch fails, it only accelerates the matter. And because the v8 has more torque, the engine mounts fail earlier. There were also quite a few posts with people experiencing the 2nd failed fan and not knowing why. Once the mounts were changed, the fans lasted.


His fan clutch comment makes no sense. He is talking about engine mounts and fan clutches when there is no interrelation there.

Bad engine mounts allowing fan to shroud contact, yes. Still no relation to the fan clutch.

Fan clutches do not explode, please dispense with the sensationalism:rolleyes:

CarDriver 11-19-2012 05:48 AM

I have to agree. Call it what it is so not to confuse. It is about the Fan Blades, not Fan Clutch.

robertobaggio20 11-19-2012 07:01 AM

Quote:

Originally Posted by CarDriver (Post 7202636)
I have to agree. Call it what it is so not to confuse. It is about the Fan Blades, not Fan Clutch.

No, its about the fan blades coming into contact with the fan shroud, when the engine mounts fail and move the engine itself physically lower.

When the mounts fail, the blades hit the shroud, especially when driving over bumps etc.. If the fan clutch itself is bad, i suppose it wobbles more and hits the shroud more, coming apart faster. So snowsled is right.

If you encounter anyone whose fan clutch came apart (is that better sir ? :) ) and thinks this is due to the fan clutch's inherent weakness, please ask them to have their engine mounts checked immediately. Fan clutch failure would be a misdiagnosis in this situation. They might change a new fan clutch and have the problem happen again, or install a radiator-mounted electric fan which would not have such issues, but their failed engine mounts may lead to other problems with the car apart from merely increased vibration and noise (feel free to correct me here).

Thank you.

rgds,
Roberto

1995i540 11-21-2012 11:11 PM

Our engine mounts also fail faster because of PS lines run right above them and once they start to leak they will eat the mount.

The fan clutch (or anything else) for that matter could be affected by severely damaged mounts.

It could also explode if plastic became old and brittle or if it seizes during hard acceleration. If fan clutch is already seized it will wear your WP bearing until it starts to fail unless the plastic is too old and once again explodes.

CarDriver 11-26-2012 11:36 AM

Quote:

Originally Posted by robertobaggio20 (Post 7202738)
No, its about the fan blades coming into contact with the fan shroud, when the engine mounts fail and move the engine itself physically lower.

When the mounts fail, the blades hit the shroud, especially when driving over bumps etc.. If the fan clutch itself is bad, i suppose it wobbles more and hits the shroud more, coming apart faster. So snowsled is right.

If you encounter anyone whose fan clutch came apart (is that better sir ? :) ) and thinks this is due to the fan clutch's inherent weakness, please ask them to have their engine mounts checked immediately. Fan clutch failure would be a misdiagnosis in this situation. They might change a new fan clutch and have the problem happen again, or install a radiator-mounted electric fan which would not have such issues, but their failed engine mounts may lead to other problems with the car apart from merely increased vibration and noise (feel free to correct me here).

Thank you.

rgds,
Roberto


Exacctly my point "Fan Blades" Not the "Fan Clutch"

Josh429er 11-26-2012 10:56 PM

Has anyone had a power steering pump shaft walk out? Lol that would be a mess Haha, I've seen that on a Duramax. Snowsled is probably the only person who sees the major problem with diesel loosing a serpantine belt.

snowsled7 11-27-2012 04:48 AM

Quote:

Originally Posted by Josh429er (Post 7216203)
Has anyone had a power steering pump shaft walk out? Lol that would be a mess Haha, I've seen that on a Duramax. Snowsled is probably the only person who sees the major problem with diesel loosing a serpantine belt.

Serpantine belt usually means there is just the one, which means it drives the water pump. So you aren't going far, thats for sure;)

Old diesels can run without electricity though, modern deisels wont start without enough battery voltage to run the computer:rolleyes:

snowsled7 11-27-2012 04:55 AM

Maybe we are just confusing the semantics. Fan clutch and clutched fan mean two different things to me.

The fan clutch is the center section that provides the variable connection between the actual fan and the belt driven wp.

If you say the clutched fan explodes, yes, if the fan blades hit something they will probably shatter. The clutched fan assumes the whole assmebly.

Understand that there are two completely sepeate parts being discussed. The actual clutch and the seperate fan blades/hub. Together they could be properly referred to as the clutched fan, or engine driven fan, as opposed to and autonomous electric unit.

Fan clutches though, do not explode.

CarDriver 11-27-2012 07:52 AM

Quote:

Originally Posted by snowsled7 (Post 7216352)
Maybe we are just confusing the semantics. Fan clutch and clutched fan mean two different things to me.

The fan clutch is the center section that provides the variable connection between the actual fan and the belt driven wp.

If you say the clutched fan explodes, yes, if the fan blades hit something they will probably shatter. The clutched fan assumes the whole assmebly.

Understand that there are two completely sepeate parts being discussed. The actual clutch and the seperate fan blades/hub. Together they could be properly referred to as the clutched fan, or engine driven fan, as opposed to and autonomous electric unit.

Fan clutches though, do not explode.

Thank you! :)

Josh429er 11-27-2012 04:15 PM

I was going to say that, but forgot. On a diesel they have no vacuum, so the brakes are powered off of the serpantine belt too. And Idk how many of you tried to stop a 7k+ vehicle without power brakes and steering lol. But I'm sure its fun.

robertobaggio20 11-27-2012 04:31 PM

Fan clutches obviously never literally explode. The fan does not come apart from its assembly spontaneously due to clutch failure. That is now clearly seen to be a misdiagnosis. The engine's mountings fail, causing the engine itself to judder especially when the car is driven over bumps etc. The fan's blades hit the shroud or something else, and the impact coupled with its fast spinning momentum causes it to become dislodged and unleash itself upon the car and its bonnet, and ultimately upon the owner's wallet. :)

Josh429er 11-27-2012 04:33 PM

I'm sure It's fast enough to look like it explodes.

S406 11-29-2012 09:29 AM

My fan blew up while I was working under the hood 2 nights ago. I dont know how but the shrapnel missed me...Mine was due to a bad upper rad mount. The fan sucked the rad into it self.

robertobaggio20 11-29-2012 09:32 AM

Quote:

Originally Posted by S406 (Post 7221091)
My fan blew up while I was working under the hood 2 nights ago. I dont know how but the shrapnel missed me...Mine was due to a bad upper rad mount. The fan sucked the rad into it self.

Glad you're ok dude. That really could have been nasty.

south26 11-29-2012 03:02 PM

Try not to kill yourself.


Andy

S406 12-03-2012 11:20 AM

Thanks...No idea how it all missed me..Found pieces in every corner of our 2000sq ft shop:)

robertobaggio20 12-03-2012 02:54 PM

Quote:

Originally Posted by S406 (Post 7228490)
Thanks...No idea how it all missed me..Found pieces in every corner of our 2000sq ft shop:)

" The force is strong with this one. " :)

You had a narrow escape my friend. Feel good about life. :angel:

S406 12-03-2012 03:47 PM

I always feel good about life! Unless I get trolled for my wheels tee hee:rofl:


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