Does this look right to you? 540i fan clutch.

[Iforgetalot]

99 540i. My fan clutch has what looks to be some kind of extension on the threads. It places the fan about an inch closer to the radiator and it makes it very easy to remove/replace the fan.

My question is. How do you think this affects the flow of air being moved by the fan since it is deeper into the fan shroud? Can this be a problem if I were to have weak engine mounts increasing the possibility of fan-radiator contact. And last, this car makes an awful loud whoosh sound when the fan clutch in engaged and I am wondering if it may be enhanced by the fan being deeper into the shroud. I like how easy it is to remove/replace the fan clutch but if taking that extension out decreases the loud airplane noise then its gone for good.

Just for reference the coolant temp stays between 105-110, no more no less, doesn't matter what the weather or traffic condition is, or how hard I run it.

Also right before posting this I looked at the picture and thought that maybe the reason for the thread extension is to move the fan away from the CAI, IDK, opinions and ideas welcome.

Fan clutch nut.jpg

[ColtonBH]

That looks strange, but I don't see it affecting airflow

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[ViolinARC]

Looks unique to me. That extra nut isn't on either the '00 or the '03 540 and I replaced with OEM. I can't see it hurting anything unless your engine mounts fail and the fan hits the radiator...

[lesguy]

from my experience, some aftermarket fan clutches are noticeably louder than the OE original fan clutch from BMW.

[auaq]

That's an extension piece for supercharger kit installation. Without that extended threaded nut piece the fan would be rubbing against on the charged intake pipe. Perhaps the previous owner must have had a s/c kit installed at some point or that it was installed for ease of fan removal (more room for a wrench to fit something like that).

[540-S3]

Dinan added those with their S/C kits. Piece of cake getting the fan off and on.

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[Uturn540]

My only concern would be the weight of the fluid drive and fan hanging farther out would put more stress on the WP bearings. How this would affect longevity, who knows. Since my recent valley pan replacement I have opted for the 88c thermostat and no engine fan at all. So far so good.

[geargrinder]

Yep. You sir have a car that used to have a supercharger on it. In addition to S3's comment, the VF kit has a nut that looks exactly like that.

From time to time there are used blower kits sold by d-bags (aka your PO) that are missing that (and other) parts. That bad news kid LaLaRay sold his kit and car that way - sold the kit missing stuff that he'd left on the car when he sold that (your car didn't come from the DC area did it?)

You could search around on the forums and/or advert it FS if you want to delete it, there might be somebody who really wants it.

[Iforgetalot]

Yep. You sir have a car that used to have a supercharger on it. In addition to S3's comment, the VF kit has a nut that looks exactly like that.

From time to time there are used blower kits sold by d-bags (aka your PO) that are missing that (and other) parts. That bad news kid LaLaRay sold his kit and car that way - sold the kit missing stuff that he'd left on the car when he sold that (your car didn't come from the DC area did it?)

You could search around on the forums and/or advert it FS if you want to delete it, there might be somebody who really wants it.

Interesting! As far as I've been able to find out, the car was originally from NY as a company car, it was then sold to the PO in Georgia who kept it for many years and now me.

The PO took good care of it and had the car cloned to look look like an m5, Style 65 wheels, bumpers, side mirrors, rear lights, door sill covers, floor mats, true dual exhaust and badges everywhere! I always wondered, why would someone make their car look like a slow M5? but whatever, to each their own. Unless, they have it SC, making it a much more up to par clone, hmmm!. By the way the first thing I did was to peel any and all M and M5 badges.

Now that you mentioned the possibility of this car having a SC it all makes sense. It also may explain why my low mileage transmission (now with Royal Purple Syncromax) whines and feels much more "notchier" than my friends hi-mileage one which now sits in my garage waiting for the tag team relay. I believe this would have caused unusual wear and tear on the transmission due to higher HP combined maybe with owners need for speed. All speculation... I don't know why the PO would not have mentioned this if it was in fact the case. Maybe Ill send the guy and email and find out for sure.

Just to satisfy my curiosity are there any other signs I could look for to determine if this car was ever SC? mounting hardware, pulleys, etc?

[geargrinder]

the first thing I did was to peel any and all M and M5 badges.

Good man! We got SOOO many 'faux AMG's' that run around down in the city here (like stock base C220 or C250's with AMG rebadges) you don't want to be in that kinda company. M-parts, cool! Fake badging, not-cool.

Just to satisfy my curiosity are there any other signs I could look for to determine if this car was ever SC? mounting hardware, pulleys, etc?

Hard to say depending on how comprehensively the kit was reverted. Obviously he missed one thing but maybe he got all the others.

Im certain none of the big parts would be still there - the mounting hardware and pulleys are the most important parts of the kit (although DoingTimeLaLaRay tried to sell his without the $$$ crank pulley too I think... )

Possibly the SAP (secondary air pump). That gets moved from the passenger side fender well to the drivers side fender well. Obv he 'should' have moved it back when he deleted the blower kit - although that's another known "not included w/ the used kit for sale because it was PITA and/or I forgot". HOWEVER from what I can see from your picture, it does look like stock SAP plumbing is in place at this point, so I assume he properly reverted that (or could have been an "SAI/SAP delete" guy when he put the kit on and then just installed stock SAI gear again when it came off...)

You look for evidence around the ABS/DSC module to see if there's signs that used to be moved backwards in the engine bay (kit comes with adapter mounts to push it backwards). Usually there's some wear marks or other tweaks left over from moving it.

The AC line up by the passenger side headlight gets replaced by a modified one to give room for the kit, if he didn't revert that it might still be there.

Also if you pull the airbox there might be some wear spots on the inside of the fender where the kit's intake pipes would go. My car wore the paint under there, and I've seen other wear points like that over there on other peoples cars.

OH and behind the airbox there's a ground bolt that gets modified for sure to make clearance room, that'd be a thing that didn't get 'taken off'. Look for a ground bolt with a bunch of black rectangles w/ brown wires going to them back there and snap a pic of what you find.

I'm sure there's other things I'm not thinking of... but honestly if you're in touch with the guy easiest is to call/email and ask.

And I wouldn't attribute gearbox wear to the S/C factor. I'd attribute that just to crappy driving skills and improper shifting. It'd be just like a fake-M-badge dude to not know how to shift properly and/or abuse the tranny with clutch dumps and whatnot.

[philly98540]

The ground bolt would be an easy dead giveaway! +1

Is that an aftermarket CAI on there? Maybe he moved fan forward for extra clearance?

[AquilaBMW]

I have seen that extender bolt on EVERY DINAN car I have come across that had a CAI, or had a tune. It pushes the fan forward for additional cooling / pulling in air. It's not just for cars with S/C. I've had about 5 DINAN 5 cars without S/C and they all had that. Actually not very fond of them after they've been on for a while and you need to remove them.

[Iforgetalot]

Possibly the SAP (secondary air pump). That gets moved from the passenger side fender well to the drivers side fender well. Obv he 'should' have moved it back when he deleted the blower kit - although that's another known "not included w/ the used kit for sale because it was PITA and/or I forgot". HOWEVER from what I can see from your picture, it does look like stock SAP plumbing is in place at this point, so I assume he properly reverted that (or could have been an "SAI/SAP delete" guy when he put the kit on and then just installed stock SAI gear again when it came off...)

OH and behind the airbox there's a ground bolt that gets modified for sure to make clearance room, that'd be a thing that didn't get 'taken off'. Look for a ground bolt with a bunch of black rectangles w/ brown wires going to them back there and snap a pic of what you find.

SAP is in its original location, well it was until it locked up and I removed it. Will replace soon.

These grounds?
ground.jpg

Well thanks guys. Its been fun chatting but now I have to go chase a new found small oil leak from the passenger side engine mount. The fun never ends with these cars. I kind of miss working on my old 77 280z. It was so easy, and cheap too!

[geargrinder]

Well interesting stuff, if Michael is right maybe he just had a bunch of sub-blower-kit Dinan mods? I'd never heard of that except for blower cars so that's interesting...

[AquilaBMW]

Well interesting stuff, if Michael is right maybe he just had a bunch of sub-blower-kit Dinan mods? I'd never heard of that except for blower cars so that's interesting...

Yeah JC .... I have two DINAN 5, non S/C cars in the toy store right now and they both have that extender. Everyone E39 DINAN I've met had it. In fact, the buggered Water I was dealing with still has it on it. They can be a pain to take off as they block off the pulleys bolts one would normally put the the holder or pulley tool on to remove the fan clutch.

[ColtonBH]

Yeah JC .... I have two DINAN 5, non S/C cars in the toy store right now and they both have that extender. Everyone E39 DINAN I've met had it. In fact, the buggered Water I was dealing with still has it on it. They can be a pain to take off as they block off the pulleys bolts one would normally put the the holder or pulley tool on to remove the fan clutch.

I've had much better luck with the stick a 1 1/8 (or 1 1/4, can't remember) wrench on it and beat it with a hammer. Seems to go nowhere, on the 5th or 6th hit, breaks free every time. Works a lot better that trying to jam tools in there and using elbow grease.

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[geargrinder]

Deleting visco fan just solves all these problems