Catastrophic Radiator Fan Failure

[djlandreneau]

Hi All,

First would like to say this is my first post, having just joined the forum.

Saturday my 540i 6 speed '99 was making a weird sound, almost as if it were turbocharged. Only made the sound at higher rpm 2500 and above, more or less. No weird indications in the cockpit, other than the noise.

Well Saturday night, on 400, as I shifted to third a loud explosion came from under the hood. Engine instruments all appeared normal, temps, everything, no lights, so I drove home - carefully.

Back in the garage I noticed three large dents protruding upwards in the hood and the paint knocked off around the dents. Popped the hood and discovered that the radiator fan was missing and had shredded the the hood liner.

Has anyone ever experienced or heard of this before? Went the BMW dealership and paid 100 bucks for a new fan. They said I might also need to replace the water pump. Advised me to hold on the hood liner and fan shroud until I resolved the problem.

DJ

[Mitch]

Yes I know exactly what that is. Your fan clutch seized up. The fan clutch regulates the speed at which your cooling fan spins, based on engine temp. When the fan clutch is seized, the fan spins at whatever RPMS the engine is spinning, which is not good.

When you downshifted, the engine sent that fan spinning into 3-4,000 rpm which broke it apart and hit the inside of your hood.

You will need a new fan, fan clutch and might as well do the water pump while you are in there. Sucks I know, it happened to me 2 years ago in my 540i6 E34.

[88e28]

Wow!! Thats the first time I heard of that. Costly repair Fan, Belts, Body work and paint. OUCH!! Welcome to the Club Join us with the World Record Drive.:luxhello:

[BMRSEB]

Yeah, happened to me as well in my ironically, '99 540i/6 as well. Anyway, it's a known issue with the cooling systems on those cars. Preventative maintenance is the key.

If you don't know the last time the water pump, t-stat, radiator and associated hoses were changed, I would just change them.

In my case, I was driving, luckily on a local street, all of a sudden battery light came on, and steering got very tight and I smelled coolant. I quickly pulled into some muffler shop down the road a bit, popped the hood and saw a nice tangled web of shredded belts (all belts gone!!), the fan clutch was almost unscrewed off and the waterpump was just barely hanging on, and of course coolant was streaming all over the ground.

Luckily, no damage to my hood as the fan basically undid itself before it could do any damage to the hood.

[djlandreneau]

Ok, well thanks for the quick replies back everyone. The BMW dealership service manager didn't think it was the fan clutch, but after reading the posts I tend to agree that is what is was, since during the driving around that day the engine (fan) was making an unusual noise, like is was spinning at too high an RPM.

Bad news is that I just finished bolting the new fan onto the old clutch, no biggie, I'll remove and replace the entire unit. Further bad news is that as I removed the fan shroud, which is shredded, I found out that the radiator expansion tank took a huge piece of shrapnel and is a mort.

Total tally, and counting is:

1. New fan
2. New fan clutch
3. New expansion tank
4. New hood liner
5. Gonna need hood work and painting

Damn good thing I love that car and plan on keeping, otherwise it is becoming more expensive than my 4 kids!

DJ

[Dominic49]

happene to me on the e30 (three times) before i learned i dont need a cltuch fan

happened to justin's e36 M3.... (still hasnt learned)

happens to often...

[djlandreneau]

Dominic49, can you explain about the not needing a fan clutch?

One thing I did find interesting was that I continued to drive the car for another 8 miles and it didn't overheat.

[Justin]

Yep it happened to me like Dom said above!! It sucked mine put a hole in my rad. BMW cooling systems are not the greatest.......

[Justin]

Dominic49, can you explain about the not needing a fan clutch?

One thing I did find interesting was that I continued to drive the car for another 8 miles and it didn't overheat.

Go electric or just go no fan at all like some people do, put some water wetter in and get a lower temp T-stat.....but I just dont like the idea of no fan setting in traffic when its 100 degree outside because no air will be flowing through the Rad. :huh:

[djlandreneau]

There is a fan on the front of the radiator, I'm assuming that is an electric one. Sounds like I could just replace my expansion tank and call it a qual.

What is water wetter?

[Mitch]

Water Wetter is made by Red Line Lubricants, its a super coolant that helps dissapate heat quicker than coolant alone. You can get it at any auto parts place.

[BMRSEB]

happene to me on the e30 (three times) before i learned i dont need a cltuch fan.
Correct me if I'm wrong (no expert here), but I think all you would need after removing the fan clutch would be a different (lower temp?) t-stat?

[Justin]

Yes there is an electric fan it only comes on when the A/C is on or when the Coolent temp gets really hot..... I guess the only time you need the clutch fan is in traffic but like i said i didn't want to take a chance with no fan because once that stock electric fan kicks on your car is already running hot.... I dont know... my fan exploded at 140mph so it was kinda my fault with that one but it does happen a lot.

[Justin]

Water Wetter is made by Red Line Lubricants, its a super coolant that helps dissapate heat quicker than coolant alone. You can get it at any auto parts place.

Thanks Mitch its about $9!

[e30bmw]

yeah i had to replace my fan two weeks ago, nothing as bad as your guys
i was doing like 130 on the highway and my power steering belt broke and broke two blades off my fan
that thing is a bitch to get on, so try and fix it the first time

[88e28]

I didn't know this is a problem. Still learning about the BMW's. Glad my parts were replaced when I had the water pump replaced.

[djlandreneau]

Just a quick update. I purchased a new fan clutch from AutoZone this morning. After getting a new one in my hand I can confirm that it was the clutch seizure that caused the failure. The new clutch turns and the one on the car only turns 20 degrees.

[djlandreneau]

Ok, everyone here is another riddle for the group. Has anyone ever removed the fan clutch? As I try to turn the attachment nut either the engine turns in one direction, try in the opposite and the belt slips.

I am assuming that there is something that I need to do to stop the engine from turning while I apply pressure to the nut.

DJ

[e30bmw]

Ok, everyone here is another riddle for the group. Has anyone ever removed the fan clutch? As I try to turn the attachment nut either the engine turns in one direction, try in the opposite and the belt slips.

I am assuming that there is something that I need to do to stop the engine from turning while I apply pressure to the nut.

DJ

i think i know what you need
when i was replacing my fan, we needed a special tool to hold that in place so that we could loosen the fan, im not sure if its the same, but i can put a picture up of it, if it will help you

[djlandreneau]

If you wouldn't mind posting the pic that'd be great. I tried using a belt wrench to hold the clutch in place but I think it's the engine that needs to not move.

[e30bmw]

yeah give me a few minutes

[DavidYow]

Damn you guys knew exactly what his issue was. That is awesome folks!

[e30bmw]

heres, the thing i used for replacing just the fan, slightly different than what you were doing, id have to ask my dad where we got it/how much it cost

and i just realized i dont know how to post pictures

[e30bmw]

if anyone wants to help me help dj, they could tell me how to post a jpg image in a reply

[djlandreneau]

Ok, figured it out. AutoZone has a clutch fan tool that you can use "free of charge." Simply put down a deposit and use the tool then return it.

From the looks of the tool http://www.autozone.com/R,NONAPP1793/store,908/shopping/accessoryProductDetail.htm it is used to hold the flywheel in place while you loosen the clutch bolt.

I'll take some pictures tomorrow and post up.

DJ

[e30bmw]

that looks like it might work
good luck

[djlandreneau]

Ok All,

Here is the latest update on the rebuild post-fan catastrophe. Still can't get the clutch off because I can't seem to find the correct size wrench and hold back - the ones from AutoZone did not fit.

Went ahead and put everything back together, leaving the fan off and the old clutch plate still attached to the engine.

Put 50/50 coolant and the Wetter Water into the cooling system. Started the car up and ran it for about 20 minutes. Temp gauge pegged where it always does - mid-level.

So, I am going to try and run the car for a while sans-fan and see what kind of temps I get out of the system.

Oh, by the way, another casualty of the fan bomb was a sensor for the A/C auto recirculation system. It is mounted to the fan shroud housing and apparently took a piece of shrapnel during the war.

Total tally so far is:

1. Fan shroud - $105
2. Fan (not mounted yet) - $120
3. Fan clutch (not mounted yet) - $105
4. Coolant expansion tank - $75
5. Sensor (on order) - $78
6. Hood repair - TBD, but based on telephone quotes $200

Grand total = $683

If you hear your engine all of sudden sounding like it is turbocharged you better stop running, otherwise the fan will ruin your day.

DJ

[BMRSEB]

Ok All,

Here is the latest update on the rebuild post-fan catastrophe. Still can't get the clutch off because I can't seem to find the correct size wrench and hold back - the ones from AutoZone did not fit.

DJ
You can also wedge a long enough screwdriver between two or so of the bolts on the fan clutch.
Basically, one end of the screwdriver will be above a bolt and the other end below yet another bolt, kinda' like you're trying to turn it with the shaft of the screwdriver, spin the fan clockwise(?) it should come off..


EDIT
Just remembered that your fan's already off, correct? If so, use the screwdriver as above and wrench on nut and turn/wrench clockwise..

[Justin]

Yeah its reverse threads.... i think

[GCR]

Ok All,

Here is the latest update on the rebuild post-fan catastrophe. Still can't get the clutch off because I can't seem to find the correct size wrench and hold back - the ones from AutoZone did not fit.

Went ahead and put everything back together, leaving the fan off and the old clutch plate still attached to the engine.

Put 50/50 coolant and the Wetter Water into the cooling system. Started the car up and ran it for about 20 minutes. Temp gauge pegged where it always does - mid-level.

So, I am going to try and run the car for a while sans-fan and see what kind of temps I get out of the system.

Oh, by the way, another casualty of the fan bomb was a sensor for the A/C auto recirculation system. It is mounted to the fan shroud housing and apparently took a piece of shrapnel during the war.

Total tally so far is:

1. Fan shroud - $105
2. Fan (not mounted yet) - $120
3. Fan clutch (not mounted yet) - $105
4. Coolant expansion tank - $75
5. Sensor (on order) - $78
6. Hood repair - TBD, but based on telephone quotes $200

Grand total = $683

If you hear your engine all of sudden sounding like it is turbocharged you better stop running, otherwise the fan will ruin your day.

DJ

Don't run it in traffic without the fan and the missing A/C module. The auxiliary fan will not operate without the module plugged in & you will risk overheating the engine in stop & go traffic.

[88e28]

not in the winter.

[GCR]

not in the winter.
I'll put money on it............

[88e28]

Sorry, I have done it. Cold temps ok, not warm temps.

[e30bmw]

i wouldnt risk it, especially in ga, its been getting warmer some days here in sc
id try and avoid traffic, but if you dont commute much daily, you shouldnt be too bad

[e30bmw]

and if your car starts to overheat, try putting the heating inside on full blast, that normally helps a little
if its hot out you might have to open the windows

[GCR]

Sorry, I have done it. Cold temps ok, not warm temps.

With a 540?

[Mitch]

Yes Wayne, my M5 started running hot without my aux fan working, 2 months ago when it was 30 degrees outside. It just depends on conditions, but it can happen. The 540s and M5s are huge engines and make a lot of heat.

[88e28]

OK. Thanks for the information.

[chrisesteschiro]

Here is what you do, remove the fan shroud, next go to a bycicle shop and they will have a 32 mm wrench that will fit, It is used to adjust something on a bike, next take a screw driver to wedge in between the other bolts on the fan, attach the 32mm to the big bolt, hit it with a hammer knocking if from passengers side to the drivers side if you are working from above...............a good swift hit is all it takes, your back in action......

[jfman]

Been considering installing an electric fan on my m5 because the same thing happened to a few guyz on the m5 board

[nakedandvulnerable]

Been considering installing an electric fan on my m5 because the same thing happened to a few guyz on the m5 board

flexalite fan and an alum rad would be nice

[Mitch]

When I bought my M5 a couple a years ago, it had a bad fan clutch. The BMW tech I took with me said "Don't rev her high when the fan clutch is bad, it would be a mess"

[GaAlpinaowner]

here is a top notch solution - and add the fan cooler
http://www.bimmerzone.com/performance_Zionsville_Radiator_E39E38.htm