Mechanical Fan Exploded! Is another one Justified?

On the same topic of WP Pulley, anyone here uses ECSTuning Aluminum WP Pulley?

Originally Posted by cn90

Schi-tzo,

One thing that gets lost in the discussion of cooling overhaul is the WP Pulley itself.
The BMW techs at dealer told me they change the WP Pulley at 120-140K or so.

Yes my water pump pulley came out in 3 pieces. I dont know if this was damaged prior to or after the explosion.
I looked for an aluminum pulley and I will likely buy one from ECS as long as it does not overdrive the pump. Apparently URO has an aluminum one but they seem to be out of stock everywhere I looked.

Originally Posted by cn90

PS: Schi-tzo, Every time I type your username, the forum software censored it LOL. The software confuses your username with poop LOL.

LOL. There is a long story behind my username but thats a story for another day and NO it does not involve poop!

Originally Posted by cn90

This is an example of cracked WP Pulley

Excellent photo!

So others benefit, I'll take the liberty of adding that nicely annotated picture to the pictorial thread of all known cooling system failure types:
- Pictorial look at typical E39 cooling system failure modes (1)

Are these the complete set of possible causes?

1. Bad viscous fan clutch
2. Bad motor mounts or transmission holders
3. Bad water pump shaft
4. Bad water pump pulley
5. Bad fan blades

The software confuses your username with poop LOL.

I got the same thing

Sure enough I went home and saw a small crack in my WP Pulley at 110K, and I replaced it.
Your root cause might have been a cracked WP Pulley.

Ever wonder why BMW WP pulley crack?
Ever wonder plastic WP pulley prematurely crack due to the pig clutch fan hanging on 7/24?

Just to prove a point going back to ScheetZo's earlier post below.

My point is a cooling system is such a critical part of a car that it should not have as many and frequent failures as the E39 does. I think the E39 cooling system can be improved upon significantly and I intend to do that.

My fan exploded at the 99k mile mark. Had it checked out and it appeared that the fan simply cracked. My wp pulley was fine, my fan shroud was untouched so it wasn't because the fan made contact. It even happened when I was cruising- not romping on it. I think the plastic just sucks and cracks due to heat.

We have the Aluminum Water Pump Pulley.

*From production date 09/1998* for the aluminum pulley as noted on our site.


Click HERE for the ECS Tuning Water pump for e39 applications.














Thanks and I hope that helps.



Joe

Thanks Joe,

I was looking around and it is funny that:

1997-2003: Same Water Pump PN for all these years

1997-?09/1998: Different WP Pulley and Different Belt Length compared with later years
?10/1998-2003: Different WP Pulley and Different Belt Length compared with earlier years

The bottom line is for my 1998 528i (build date 10/1997), I do not have the Aluminum WP Pulley option.

Cam, Turner has them, but more $$ - here.
I replaced all those questionable composite pullies with these ones (WP & PS). No more worries for me.

*From production date 09/1998* for the aluminum pulley as noted on our site.



Sorry , I did not know your production date.


Yes the one you have # 11511730554. with production up to 9/1998. So the stock is your option.



Sorry for the confusion. Thanks


Joe

Originally Posted by ECSTuningJoe

We have the Aluminum Water Pump Pulley.
Thanks and I hope that helps.
Joe

My car is a 2002 so this pulley should work. I am not too keen on the fact that this pulley will overdrive the WP. However i doubt this change in diameter will result in a statistically significant difference in terms of WP function over a stock pulley.

Originally Posted by *****zo

My car is a 2002 so this pulley should work. I am not too keen on the fact that this pulley will overdrive the WP. However i doubt this change in diameter will result in a statistically significant difference in terms of WP function over a stock pulley.

Schiit-zo, where do you get the specs for the ECS pulley that it would cause an over drive to the WP? Does the ECStuning's pulley diameter smaller I assumed?

I would also think the difference is insignificant, however a little over-drive the WP may not be a bad idea!

It seems to me that later years have shorter belt length to accommodate the ? decrease in diameter of the WP Pulley.

Earlier years belt: 6K1555 (PN 11281469266).
Later years belt: 6K1538 (PN 11281706545).

Can anyone measure a stock 1998 WP Pulley against a later year (such as 2001) WP Pulley for me?
I am curious to know if this is the ONLY difference.

If so, then I can use the Aluminum Pulley but switch to the shorter belt.

Originally Posted by 16valex

Schiit-zo, where do you get the specs for the ECS pulley that it would cause an over drive to the WP? Does the ECStuning's pulley diameter smaller I assumed?

I would also think the difference is insignificant, however a little over-drive the WP may not be a bad idea!

Got the info from ECS website. Below is the description on the pulley
http://www.ecstuning.com/Search/Pull...aign=postreply

Originally Posted by ECS

Made of CNC machined billet aluminum, our ECS pulley will never crack or break leaving you on the side of the road. To help with cooling efficiency, this pulley has been engineered with a 7% overdrive ratio. This simply means this pulley is slightly smaller than the original pulley letting the water pump turn just a bit faster. Hard anodized finish to help prevent corrosion. This pulley is a direct replacement using the factory belt and original hardware.
Pulley dimensions:

* Stock BMW Pulley - 5.185" OD
* ECS Billet Pulley - 4.835" OD

Originally Posted by cn90

Can anyone measure a stock 1998 WP Pulley against a later year (such as 2001) WP Pulley for me?

I would measure the one out of my 530i but it is in pieces. However according to ECS as shown above the stock pulley has an OD of 5.185". I assume this is the measurement for post 9/1998 cars.

I'm running evosport underdrive pulleys.





There is also the option of finding an early m50 at the junjyard with a OE metal pulley on in. Here is one I put on an S52 for a customer.




I've also installed Turner, UUC, Eurosport, and Rogue Underdrive pulley sets. All fit well but some are less flashy than others.

the TMS pulleys fit and look as close to stock as aftermarket parts can get so if your looking for stealth that's what you'll want. EvoSport through bimmerworld are nice, somewhat flashy though and underdrive slightly more than the TMS pulleys.(they seem to have an ordering glitch that they had a few months back fixed as well now too.) The rogue pulleys are even more underdrive on the WP pulley than the TMS and the Evosport yet draw a little more attention than the TMS pulleys but no where near as flashy as the Evosport's. The eurosport pulleys have a greyish sheen to them, they fit well, and while they are clearly noticeable they don't look out of place in the engine bay.

I have to say that I've very glad to see that ECS is offering the single water pump pulley alone as that is what many of my customers have really wanted but went with under drive pulleys for the reliability factor. Will you be doing a single PS pulley in stock diameter as well? They fail in time also, just not usually as fast as the WP pulley.

Originally Posted by cn90

It seems to me that later years have shorter belt length to accommodate the ? decrease in diameter of the WP Pulley.

Earlier years belt: 6K1555 (PN 11281469266).
Later years belt: 6K1538 (PN 11281706545).

Can anyone measure a stock 1998 WP Pulley against a later year (such as 2001) WP Pulley for me?
I am curious to know if this is the ONLY difference.

If so, then I can use the Aluminum Pulley but switch to the shorter belt.

Belt size change also corresponds with the change from hydraulic to mechanical belt tensioners IIRC. There are many slight changes to the belt drive and accessories as BMW progressed through the different updates made to the m/s 50/52/54 engine platforms.

Originally Posted by bimmerteck

I've also installed Turner, UUC, Eurosport, and Rogue Underdrive pulley sets. All fit well but some are less flashy than others.

Aftermarket underdrive pulley kits are out of the question. I try as much as possible to avoid installing aftermarket (non-OEM) parts.(says the guy with a chevy engine in his BMW!! ) What I mean is I try to stick with OEM parts that I can simply go to a dealer or other local parts counter and buy the part.

If I had that underdrive kit and the belt went out, I would be stuck waiting to get a replacement from Turner as opposed to going to the dealer etc.

Originally Posted by *****zo

Aftermarket underdrive pulley kits are out of the question. I try as much as possible to avoid installing aftermarket (non-OEM) parts.(says the guy with a chevy engine in his BMW!! ) What I mean is I try to stick with OEM parts that I can simply go to a dealer or other local parts counter and buy the part.

If I had that underdrive kit and the belt went out, I would be stuck waiting to get a replacement from Turner as opposed to going to the dealer etc.

Nonsense, Belts are not some mystical BMW OE part, they are standardized. I simply write the new belt size in the cars owners manual so if someone needs a belt in the future it's right there with the rest of the vehicle's information. You can walk into nearly any parts store in america with a belt PN such as 6pk1670 and come out with a belt that has 6 ribs and is 1670mm in length. Which is more likely to leave a customer stranded, waiting on a pulley to get shipped from the nearest BMW dealer or getting a belt from the local napa to get the car home where I'll promptly put a proper continental belt back on there? (and generally throw the off brand belt in the trunk as an emergency spare)

Call your local napa/autozone/gas station and ask if they are more likely to have a serpentine belt in stock or a plastic water pump pulley for a BMW. My under drive pulleys actually use a more common belt size than the BMW did originally. I have NEVER had a single aluminum/steel pulley fail, but I can't count the times a broken pulley has forced a car to be towed into the shop. The only cars' belt drive's I don't put total faith in are the customers with superchargers in which case I sell them a new spare belt with the install and place it in with the spare tire b/c some supercharger kits do run very strange(long) belt sizes.


You might also take careful note I'm the one who posted the picture of the "sometimes believed to be mythical" nearly fail proof OEM metal water pump pulley.

Originally Posted by bimmerteck

Nonsense, Belts are not some mystical BMW OE part, they are standardized.

And here I thought my belt was made of special rubber designed to specifications defined by BMW engineers !!
Unless that belt is used on a specific vehicle, you are less likely to find it in stock at Napa or other parts store as a the stock belt would be. Parts used by OEMs are also more likely to be in production longer. I have worked on cars long enough to appreciate the convenience of stock parts when it comes time to replace them.

But I digress. The purpose of the thread is more about the mechanical fan and its explosive ways.

Well, I thought that fan issue was already solved with an electric fan, I know mine is.

No more stock fan and clutch = no more exploding fan or failing clutch.

Originally Posted by bimmerteck

Well, I thought that fan issue was already solved with an electric fan, I know mine is.

No more stock fan and clutch = no more exploding fan or failing clutch.

I agree with that plan. What controller do you use for your electric fan?

Originally Posted by *****zo

I agree with that plan. What controller do you use for your electric fan?

I have used most often a simple and reliable BMW based 2 speed setup. Temp switch screwed into an extra bung TIG welded to the radiator controls 2 fused (20A/30A) relays (low and full speed) routed through a stock aux fan harness borrowed from an e34 in the junkyard. The part numbers in my homemade setup are as outlined below.

Temp Switch is PN 61-31-8-363-677 91/99C
Diode Relay for low side operation PN 61-36-1-391-397
Full speed relay PN 61-36-1-378-238
Low speed Resistor PN 17-40-1-373-177

I have also used a perma-cool aftermarket dual fan controller to control 2 fans independently via relays so I could control a pair of fans (one large puller on the radiator and a smaller pusher for the AC condenser) on an aluminum radiator in an e39 530 I supercharged. I don't recommend this however as it is an expensive option and requires a circuit to relay the DME false information so it thinks the PWM aux fan is still in the car and working or it will throw codes.

PS, The diode relay can be used to trigger a speed (low or high depending on where it is in the harness) with another input other than the thermo switch, for the track guys I plug the diode switch into the high speed so they can pre-cool at the flip of a switch before a track session, for the street drivers I wire in into the AC compressor button to help automatically increase AC efficiency in traffic. For one driver I've even set it up with two diode relays and a two position toggle switch so the driver could override the fan to spin either speed on command.

Originally Posted by bimmerteck

I have used most often a simple and reliable BMW based 2 speed setup.
Temp Switch is PN 61-31-8-363-677 91/99C
Diode Relay for low side operation PN 61-36-1-391-397
Full speed relay PN 61-36-1-378-238
Low speed Resistor PN 17-40-1-373-177

Thanks for the info. I am glad you posted it. I had looked at using that sensor but could not decide between the one you posted (91/99) and part number 61318361787 which is 80/88 C.
I think the 91/99 will match better with the M54 thermostat.

I will place the sensor on the lower radiator hose using a splice adapter.

Originally Posted by bimmerteck

Well, I thought that fan issue was already solved with an electric fan, I know mine is.

No more stock fan and clutch = no more exploding fan or failing clutch.

I don't care if mine is going to explode... from where they're..

Originally Posted by *****zo

Thanks for the info. I am glad you posted it. I had looked at using that sensor but could not decide between the one you posted (91/99) and part number 61318361787 which is 80/88 C.
I think the 91/99 will match better with the M54 thermostat.

I will place the sensor on the lower radiator hose using a splice adapter.

Cool, yeah the 80/88C runs nearly continuously with the later thermostats. Don't forget to grab a few extra OE relay sockets off a car at the junkyard, the factory ones are made to snap together inside the E-box and can make the additional relays look like they came there from the factory.