So, my fan blew up this morning and...

[Mr Bingley]

Ok, I replaced the fan with an MTC/Ronak new unit this spring (along with installing an S54 radiator and new fan clutch). Well, this morning, admittedly while pushing it WOT against a 911 twin turbo), something happened (I think my SC bypass valve vented--in any event there was a sudden loss of power and a "pop") and the fan exploded--sending a blade through the radiator and causing as yet undiagnosed other problems. But for sure I need a radiator.

Sympathy aside (its the chance I take), the question is what to do now? Replace with another S54 radiator and new fan blade (makes me nervous to say the least), or go a different route, and if so, what route? I'll deal with whatever other damage happened later, as I discover it--the car sputtered and was not running well at all while I limped it home (no overheating--I was only a mile or so so from home), but came back to life once I parked it (in a place to let it drain the rest of the way). Here are the parameters of what I do next:

-for sure took out the radiator, fan, fan shroud (I only had about a minute to look at it as i was then late on my way to work)

-S52 with VF Vortech V3 SC and S54 oil filter housing and cooler

-Cost doesn't matter

-Want the best solution so as not to ever have to worry about cooling OR the fan exploding

-Already have Stewart pump and all components in cooling system replaced within a year or so (under 4K miles)

-want to fix it as soon as possible

-do my own work

-have complete shop facility at my disposal

-hope to h**l I didn't do serious damage (like blow the head or something terrible), but I don't think so

Waaaa

[rf900rkw]

1- Remove damaged radiator, fan, clutch
2- Install new radiator and bleed properly
3- close hood

[jajou318]

Once it happened you pulled over and turned it off? Did you notice the temp gauge creeping up?
It sounds like you caught it in time to turn it off so you shouldn't have to be worried about a blown HG.

I would do S54 radiator (not worth going Al) and replace the mechanical fan with another mechanical fan(maybe go with a diff brand..)

http://forums.bimmerforums.com/forum...ght=fan+clutch

https://www.youtube.com/watch?v=NVen...e_gdata_player

[Z3speed4me]

This is why I don't trust that stupid fan... twin electric spal's all day every day.

[Mr Bingley]

Yeah, I pulled over immediately, turned it off, put the key in the on position, and pushed the air conditioning button to run the auxiliary fan. It never got hot, but I let it cool down for while. On the drive home, I ran the heater at high and max fan, and left the air on to keep the aux fan running. The hottest it got was just below the right hand hash mark on the gauge, and I turned it off then and coasted the rest of the way home (all down hill). Coolant leak is slow, so there was still plenty of coolant to leak out all over my driveway when I got back. Not worried about overheating causing a blown head, but a little concerned about what might have happened in the first place--I think the exploded fan was a symptom, not a cause, and it's running poorly afterwards is concerning. No smoke out the back, and the running cleared up as I was fiddling with the SC ducting, Might have sent a piece of blade through some intake ducting between the MAF and the SC, or severed wiring.--I'll have to see when I get a better chance. Hard to walk away from it like that without going in deeper, but I was already late.

[gmushial]

Replace the radiator (obvious), but toss the mechanical fan and replace with an electric one (thereby precluding any recurrence).

Beyond that: sorry to hear that this happened.

[Z-Thrizzle]

I would recommend putting a new S54 radiator, new belts...they could be damaged from the debris.
Install an electric fan (like Spal) and have it controlled by a separate unit that monitors coolant temp.
I'm using a unit from Flex-a-Lite and it works well
http://automotive.flex-a-lite.com/ac...ontroller.html
You can either put the sensor in radiator by the hot section or in the hot upper coolant hose.

[BMWBergy]

If it was me...

...and if cost was really not an issue...

...and I wanted supercar performance with upwards 400hp to 'beat' 911 Turbos...

...I'd go with an LSx conversion. Sorry, not a BMW solution, but an eventual dream.

[Mr Bingley]

Well, cost is not an issue to deal with the fan explosion, but I wasn't planning on dumping 6K into it in one fell shot. That being said, I do plan on going stage 2 and 6 speed before next season. Anyone have an idea as to what AL radiators are better than S54 stock, and what electric fan is the best--totally agree about having an electric fan separately switched, I would want it ahead of the thermostat in the system if possible, so it comes on before the thermostat opens, I think, and probably have at least a high and low speed. I guess the real question in my mind is whether there is an AL option that is better than S54 stock? I have about a week to source the parts and draw up the plan--I won't be able to do anything to it until the weekend, at the earliest (possibly some tear down), for now I just have to arrange getting it flat bedded to the shop I do my work in (I have a friend who owns a shop where I can wrench away to my hearts content, with my own lift).

[DrSasha]

I have zaionsville. Pricey but the best. Oil cooler, perfect fitment...
Spal of course, no mechanical bomb for me...

[Scarceas]

I would (and did) do the fan delete mod (aka "FDM"). This is precisely why I didn't just replace my fan and fan clutch; since the parts are failure prone I didn't want to be repairing damage when the new fan clutch failed.

Since penny pinching is not an issue for you, I could understand doing an electric fan conversion if that makes you feel more comfortable.

I did the FDM in the midst of a heat wave here (we may have set a record for consecutive 100+ F days). I drove through that with no issues, and did a couple of autocross days including letting the car sit idling for extended periods at 100+ F ambient... Overheating is not a problem.

I'm beginning to suspect that you can just remove the fan and call it a day. However, I went with one of the kits to do the aux switch, thermostat, and Redline Water Wetter. I suspect the lower temp thermostat does not help at all. The aux fan switch makes sense to me, though, and I notice a difference in how quickly it will kick on now. I also believe in the water wetter product, but I won't swear by it. Still, at less than $100, I figure the kit is worth it. Certainly better than replacing another radiator!

Good luck to you!

[BMWBergy]

In terms of consistency of product, Zionsville Autosport radiator options and packages (including electric fans) are hard to beat. In terms of price, they're not cheap. You should look at them for total-cooling solutions.

I've only had my hands on one Mishimoto Aluminum radiator (for my WRX), and though there had been complaints about their dimensions and consistency from the Subaru enthusiast community, mine was spot-on in terms of dimension and alignment. It was 'straighter' than my OEM S54 radiator, actually, which is slightly rhomboid vice properly rectangular.

[rf900rkw]

-totally agree about having an electric fan separately switched, I would want it ahead of the thermostat in the system if possible, so it comes on before the thermostat opens

For crying out loud, WHY? The only time a fan is needed, the only time it has ANYTHING to do, is when the temp of the coolant exiting the radiator is approaching normal engine operating temp. If the coolant exiting the radiator is already cooled, the fan will do nothing. This is why BMW and all the engineered fan kits put the temp switch on the cold side of the radiator.

You will have better results with just the stock Aux fan and putting the effort into making sure the radiator and shrouds are properly sealed than you will dangling the biggest Spal fan somewhere near the radiator. Unless you spend a large amount of time under full boost at insanely low speeds (<30mph), the aux fan is more than enough.

[luciano136]

1- Remove damaged radiator, fan, clutch
2- Install new radiator and bleed properly
3- close hood

4- don't race a 911 turbo; you won't win

On a serious note, what makes the stock fans fail? Are there any signs or is there anything else to look for? I still have the stock fan as well.

[Mr Bingley]

For crying out loud, WHY? The only time a fan is needed, the only time it has ANYTHING to do, is when the temp of the coolant exiting the radiator is approaching normal engine operating temp. If the coolant exiting the radiator is already cooled, the fan will do nothing. This is why BMW and all the engineered fan kits put the temp switch on the cold side of the radiator.

You will have better results with just the stock Aux fan and putting the effort into making sure the radiator and shrouds are properly sealed than you will dangling the biggest Spal fan somewhere near the radiator. Unless you spend a large amount of time under full boost at insanely low speeds (<30mph), the aux fan is more than enough.

I think the fan failed because the SC bypass vented suddenly releasing the momentum on the clutch, flexing the blades beyond tolerance, at least that is my current operating theory. I don't know that I could bring myself to delete the main cooling fan altogether with no replacement--complete lack of faith. The Zionsville site is not loading at the moment--do they sell a complete kit with AL rad, fans switches, etc.? Anyone have a link that works?

[luciano136]

I have the Ireland Engineering aluminum radiator btw. E36 fitment but works just fine, especially if you no longer have the stock airbox. Straight drop in.

[BMWBergy]

I think the fan failed because the SC bypass vented suddenly releasing the momentum on the clutch, flexing the blades beyond tolerance, at least that is my current operating theory. I don't know that I could bring myself to delete the main cooling fan altogether with no replacement--complete lack of faith. The Zionsville site is not loading at the moment--do they sell a complete kit with AL rad, fans switches, etc.? Anyone have a link that works?

http://www.zionsvilleautosport.com

I just called them at (317) 873-3216 to see what was up. Big storm on Friday knocked them down. They are trying to get themselves back online at this time. Give them a call, though!

[kojohns]

On a serious note, what makes the stock fans fail? Are there any signs or is there anything else to look for? I still have the stock fan as well.

There are two schools of thought with regard to root cause...
1. Water pump bearings going introduces wobble in the fan
2. Fan clutch itself fails internally introducing wobble in the fan

And then two schools of thought of the result of the root cause...
A. The wobble allows the fan blades to come in contact with a component on the face of the engine
B. The wobble causes such harmonic vibration in the fan blades that it can't take the forces

[gmushial]

4- don't race a 911 turbo; you won't win

On a serious note, what makes the stock fans fail? Are there any signs or is there anything else to look for? I still have the stock fan as well.

Since he's running FI, might not be a too unfair fight ... with a S54 type of RWHP, even with a 3.73... don't even bother:



but if we're talking LS-2 type rear wheel torque and given that the Z is 300lbs lighter - the 911 might have hang its head in shame (and that's with near matching diff ratios - with a 3.73 it would be even more true).

[luciano136]

Since he's running FI, might not be a too unfair fight ...

That extra shift costs time. You hit 75mph in 2nd in the turbo. Even stock, that thing pulls like a freight train and it can put the power down easily. Add a simple ECU flash and exhaust and you are over 500hp.

[Randy Forbes]

I think you'd better take a look at all your intake plumbing while you're at it. Big surge like that could've dislodged a hose.

First turbo installation I did, a hose came loose on a trip around the block__had me pretty shook up (car running terribly) until I saw how minor it was: WHOOSH-ppfffttt, sputter, limp, limp ...

Here's a Zionsville rig I installed a while back; they make gorgeous stuff, at gorgeous prices!

[ctlynch]

If it were me, I'd be throwing in a Zionsville S54 Super Competition radiator setup. Ultimately when I need to do a cooling system refresh on my '01 M Coupe that is what I plan to do. I've got a Zionsville in my 530i daily driver and it's been great.

[Mr Bingley]

Well, I never had a chance with the 911 twin turbo, but that wouldn't stop me from giving it a try; I'm only running 6 lbs of boost at the moment with the stock diff (325?), and that is just not enough. I was in 2nd when it all came apart (I think), getting ready for the shift into 3rd. I think what got me this morning was that ambient air temp was in the 50's and the SC maxed boost before I maxed RPM, thereby forcing a blow off--first I've experience with this set up. Water pump and fan clutch are new, so shouldn't have caused a wobble--fan clutch is a Meyle, which I believe is OEM on our cars. I'm glad to know its not me with the Zionsville site. I'll try calling here in a minute and see what I can learn.

[luciano136]

There are two schools of thought with regard to root cause...
1. Water pump bearings going introduces wobble in the fan
2. Fan clutch itself fails internally introducing wobble in the fan

Thanks! I guess I would still be at risk for number 2

[Mr Bingley]

I think you'd better take a look at all your intake plumbing while you're at it. Big surge like that could've dislodged a hose.

First turbo installation I did, a hose came loose on a trip around the block__had me pretty shook up (car running terribly) until I saw how minor it was: WHOOSH-ppfffttt, sputter, limp, limp ...

Here's a Zionsville rig I installed a while back; they make gorgeous stuff, at gorgeous prices!

I'm hoping you are right about that--seemed like it to me at the time. I like the set-up pictured, I certainly don't want this problem again. Looks like Zionsville (from their eBay page) recommends deleting the aux fan, which would make more room for the IC heat exchanger anyway--every cloud has a silver lining. Interested in the S54 super comp set up mentioned.

Zionsville's site is back up, and the S54 super competition set-up appears ideal, and is not bad at $1,025.00--not when you factor the cost of a new S54 rad, a new fan shroud, a new fan blade and clutch + the risk of having to do it again. I think I will go with it, but I'll call tomorrow and speak with a human about it for sure.

http://www.zionsvilleautosport.com/s...code/ZSSSC.htm

How could I tell it is a Monday? (got to work late for my first court hearing, the phones were out, my client didn't show, the judge was pissed at him and took it out on me, one of my secretaries called off at the last minute for no good reason, I'm still waiting here for my last appointment who just called to say they would be 45 minutes late, and MY CAR is sitting in my driveway over a pool of antifreeze without me there, and it will be dark by the time I get home to look at it). I'm not complaining, I'm lucky to even have a job and an MZ3, and it was my own fault, but I am venting a little.