The clutch fan does a lot... the auxiliary fan is for the ac condenser. The clutch fan is for the engine.

Thank you Nathan, sooo much !!! Your videos are always right on point with the situation that my 2001 BMW 530i/M54 is in. The car is an absolute blessing. I paid 1,900$ for it and at the time it was in much better mechanical shape. I must admit I drive it at 130mph. In 100’ weather and its phenomenal ! I cannot afford the dealership prices for my mechanical work and the shops ? Well let’s just say, I’d rather do it myself and learn my car. I watch 3 different guys. You,50’s kid and the Doctor. I appreciate you all !!! FYI: All 3 usually have the same result and hypothesis. Each with their own opinion and angle. Resulting in the same running vehicle! My car is ironically just like Ambers blue 525/530 !?? Thanks again, Major respect & God bless you and your business!!! Michael R. Saunders

Damn... look at that new shop!!! You’re helped me though years of happy E39 ownership. Just drove down to Florida last week and picked up a E53. Thank you

If you have dead viscous clutch on fan, it does not speed up when needed. what a surprise...

Removing the mechanical fan may be good advice for those living in a rural area with a temperate climate, but don't try that if you live in the tropics, and especially in an urban area prone to traffic gridlock.

In Arizona when its 115 to 120f during the summers it is a good idea to run the mechanical fan with the electric fan. In Missouri you can get away with not running the mechanical fan on the car ...

Good video Nathan. Thanks again for saving me time and money, when I bought my blown e60. Planning on finishing the transmission job today. Loving my BMW thanks to you

Great video for us M54 guys, Nathan. Thanks for sharing.

Hey Nathan. Just finished dropping the transmission valve body and replacing the rubber sleeves. Shifts Sooo much better, Thank you so much. I think I need to do solenoid in the future, because shifts seem a little delayed, but way better.

hey nathan. i contacted you on fb about a video on parts/ cheap parts that you use and recommend for the e39 and after watching this video i guess a cool idea for a video could be like a e39 hacks video where you discuss what you think owners should do to make their car the best it can be for the best price etc... thanks for everything you do

I've gotta disagree with you on the clutch fan on this one! On my m52tu that clutch fan works great to keep the engine within temp. (The cooling system did blow up a year ago but that was due to a cracked radiator that bled all the coolant out, overheated pretty quickly after that!) Once I'd replaced the radiator, changed out the pump, thermostat, pipes etc, engine runs constant at 96°C/97°C. Sat in traffic it can go up to 98°C/99°C but comes down pretty soon after. Interesting to see the different the performance pump I installed does, when accelerating the temp can drop quickly to as low as 78°C before making its way back up to 96°C (I rekun the thermostat is programmed for the speeds the OEM pump can cool the engine, and can't close quick enough when this one starts moving coolant!, my theory anyway.) And all this, with no AUX fan. I actually pulled the AUX fan last month, only to see it was completely fried, black, looked like the circuits had been on fire. (no idea how long it's been like that, maybe years) and when replacing it, couldn't get it to come on to test whether it worked on not. Had a read through some manuals, and forums, and called a local expert: from what I can gather, the AUX fan will only kick in based on certain circumstances (on the e39 528i anyway.) If the engine temperature exceeds 115°C then it'll kick in high speed. It'll kick in low speed when you first turn on the A/C. It'll spin one rotation on engine start. I believe there's also some other situations it's programmed to come on with such as if the outside temperature is over 30° and engine temperature is over 98°C then it comes on low speed and some other variables based on the different temp sensors around the engine. Essentially engine driven fan is adequate, and AUX fan is a backup for certain situations the radiator needs more air pushed through it. (The AUX fan is actually called the 'pusher fan', it's main function is to push more air though for the A/C.) SPEAKING OF: It will not work at all if there's not adequate A/C pressure. Couldn't get mine to kick in with A/C OR engine temp, then I had the A/C re-gassed and it kicked in right away once the engine starts, I think it's a diagnostic test thing to check if it's all working, doesn't throw up any dash lights, but if it comes back non-spinning then it stores a code in the OBD. When I read mine, sure enough, the code for non-functioning fan comes up (one for incorrect voltages due to the fuse being blown, and one because of inadequate A/C pressure), which will either be because of no A/C pressure or the fan is bust, or the fuse is gone. (The 50a is for the fan). I can only imagine with yours the touching the battery cables together somehow makes the computer ignore the fan code and run it anyway. Anyhow, oops, long comment, sorry! Damn Germans and their engineering! Gotta love them. No way an expert here, just had the pleasure of pulling apart my own e39!

I have to disagree with removing the clutch fan because it really does work! I don't think my electric fan has ever worked but my e39 has never run hot even in mid-summer

I have to say that my e39 e fan never actualy workt untill I fixed only visco fan was working, and it never overheat not even on sommer bei 35 celsius,so what i‘m trying to tell U that every component is there for purpose. Visco fan is there to pull the hot air from the radiator e fan to push cold air in the radiator.

on another note, Tungue and grove pine would look nice on the inside walls. 3/4 inch . it would also make it easy to attach and screw things anywhere you want on the walls shiplap is the cheapest.

Had a fan issue on my e70 it over heated in drive thru on wife she immediately pull out of line and shut it off. Couldn't find anything wrong. Even fan was good turned out to be the harness connector where the fan plugs in. Prongs was spread to far over time and wasn't making a good contact atleast i got a new spare fan for when it does go. Not if it does hahaha. Great video Nathan

nice job on insulating. Thanks for tips on fan .

Would that be a potentially equal scenario with an '00 e46 with a M52TUb25 or 28 as well? Did I replace my cluth fan assembly for nothing back when I basically rebuilt my cooling system?. Electric fan still works good though. Yes, I still have it albeit it's been sitting too long. Still debaiting to dig back into it.

I had that exact problem on the exact car and I solved it the exact way you did, stopping letting it cool off and then rolling into my driveway. I had a 2001 E39. Unfortunately I didn’t see this video until after I sold my car to the Junkman a week ago. I replaced the reservoir bottle, the water pump, radiator sensor, several coolant hoses, upper and lower, and I replaced the plastic thermostat with a metal one. None of that worked it still overheated. When I bought the car a year and a half ago the sensor plug for the reservoir bottle wasn’t there and there was not even a broken wire. I didn’t know what to do about that because I’m not a BMW expert. If I knew how I would’ve rewired and replaced the sensor. I wanted to sell the car for a good price because aesthetically it was in excellent condition. However, you cannot explain to people why your car is overheating and expect them to still buy it anyway. For some reason on these computerized cars with all these sensors and computers and overheating problem can come from one of half a dozen areas. It seems to be just too hard to track down these problems now. Does anybody remember when it was just a leaky hose or radiator that you can replace and solve the problem, not anymore.

How about on the M62TU? Turn on the AC - that auxillary fan is either nearly idle or SUPER LOUD! No middle ground... I also took off the clutch fan my 540i. Can't chance it... Noticed it does nothing for the temps in that car either.

Hey Nathan, fellow e39 owner here. Have you ever dealt with knock sensor codes on the e39s? I have the DME D4 code for cylinders 5-6 knock sensors on my 97 M2b28. Recently redid the top end and installed a brand new single vanos from BMW. What are the chances of bad knock sensors destroying a M52? Current symptoms are long cold cranks, rich start ups (grey smoke exits the exhaust and smells like fuel, not always though.) I ordered the part but will not be here til next week. What are your thoughts on driving the car until the part is installed? It is in safe mode right now.

Okay so recently the serpentine belt came off my 2000 E39 5 speed 528i. I had the hardest time trying to get the fan clutch off,( Didn't even get it off) simply because i didn't have the tool specific for the job to hold pulley and what not,anyhow. I managed. To take the blades off from the fan clutch. And was able to work with that and was able to reinstall the belt. Shroud was also destroyed due to fact that belt came off. And i saw how on the car you showed. You didn't have the shroud and or fan clutch with blades on. So i am pretty much wondering. Could i do the same to my car, and eliminate the shroud, nd fan clutch with the blades. and just rig up the coolant tank someplace reasonable. And if so. Do you have videos of how you set that up. So i can attempt to do to my vehicle. And to go back to the main question. Is it safe to drive the car without the fan shroud and or fan clutch and blades. Sorry for the unorganized relaying of my thoughts.

Does the clutch fan do anything on a m52 engine as opposed to the m54 ?

Can I use aluminum thermostat on the m54 or no? Has the quality gotten better

So you need to touch the positive and negative battery cables together when disconnected from the battery to reset the fan???

I have been using Evans waterless coolant for about 5 yrs.. It's boiling point is a lot higher than antifreeze.. so you will notice a temperature rise and slow leak vs a boil over... I usually wouldnt even think about a so called additive. but this has been approved in the aerospace industry.. And having specked in material for both the military and BAC(Boeing) stuff for 20 yrs + ......it goes through extensive tests etc b4 being accepted..( almost impossible stuff)..Todays cars with aluminum engines and plastic parts this could save you..Just my 2cents...

I'm surprised that a missing AUC sensor can knock out the fan, it should only control vent re-circulation in the cabin when in auto mode. 9 out of 10 BMW cars I work on, I find the AUC sensors are faulty and most people don't bother changing them. I'm going to test this theory on other models now

Lost three fins on my clutch fan.should I just remove it? And it I remove the shroud how to attach the rad overflow tank to radiator?

What was the little box that you said needed to be plugged in called

Hi Nathan my E39 530 D keeps on blowing the turbo , any tips , what's going on ?

The little plugin box you referred too in the front on the left side of the radiator, is it the AUC sensor???

Can u drive your car without clutch fan ? It will overheat

So how much and where to get an engine for the 2000 528i ? Heard u mention $500 ish

Can I swap an M3 M56 motor into my 530i? Do I need the computer and other parts? My car is an automatic ZF trans. Would a supercharger be a better solution?

Nathan I have 1999 540 I'm getting po455 code I already change the purge valve and the gas cap but I'm still getting po455 code could I be the charcoal canister that's bad??

is it the same for a M62 non vanos 540i?!

Don’t have an e39 I have e90 and F31. I love your videos.

U took the fan clutch/blade out. Does t that effect your trans temp? It looks like u took the ac fan function away when u did this "mod". Does yiur ac work properly

i had that problem with the electric fan. I bought a brand new hella plugged in, checked and nothing. I check the fuses i check the water temp sensor all perfect but no fan... Then i try with the ac nothing... I checked when the coolant temperature to be high if it will kick in nothing. I check the cable if it was cut somewhere but not. Then i cut the plug completely and i solder the wires together just to be sure the plug was problematic and finally it start working. 2 days later again the same problem. All the wires were black like they took fire and some of them corroded. Then i decide to scratch them each one of them and solder them again. 7 months now it's working finally as it should be.

How or what mechanism pulls the head bolts out of the aluminum block? I get the idea of limping it home by starting cold and flooring it a short distance before the temp begins to rise, then coasting a distance. But, doesn't the motion of the car and the air flowing thru the radiator give some cooling effect even if the fan is not turning (i can understand overheating at the stop light) but while in motion the radiator should do its thing, right? What about turning the heater on full blast, or are you assuming zero coolant flowing thru the engine? But then the head bolts being pulled out of the head, where does that come from? They are somehow yanked out, shearing off the threads AND the aluminum loses all its properties as a metal, becomes crumbly or spongy and therefore a helicoil or something won't allow the heads to be tightened back down? What temp does the engine operate at, does the exhaust wind up glowing red hot when in use? What's the idle rpms on this car? This whole concept is really stripping my gears.

Nathan I love your vids your the man! But one thing you say the fan clutch doesn't do anything but that's not true I only run a fan clutch on my manual 2001 330xi with no factory aux fan and it runs great. Car came with electric fan from factory because it's a manual 5spd but I swapped it out and barrowed the electric fan to my other e46 330ci to see if the electric fan was faulty but it was a leaking water pump problem for the 330ci not fan. It had no coolant or little. So I left the fan clutch in the 330xi manual and it runs great. Also if you want to see the digital number of your cars temp on e46 just hold down the trip odometer reset button for 5 seconds til you see 0000 then quickly scroll to 19 by pressing in in increments. Wait 1 sec til you see 19.0 then quickly scroll to 7. You see the exact temp of engine eg.76 degrees Celsius. It will be in celsius

Hi Nathan, I have a 2003 e39 wagon overheats after idling for awhile but I notice the lower radiator hose isn't getting hot. Have you ever run into that issue?

Engineers seemed to be playing Uncharted 4 with such a mysterious design

My clutch fan blew up 😅🤣

does the accessory fan ever turn on other than for a/c on a prefacelift 2000 528i?

I have a very well maintained 2003 530i auto Msport with 177000 indicated miles Bought it new in Camarillo CA. Mobil 1 10w - 30 and Castro full Synthetic oil with new filters every 5000 miles or so. The only problem I have had over the past few yeas is an intermittent transmission failsafe warning and the traction control light illuminating after warming up the car and restarting after stopping the engine. I got a new battery and reset the computer, and that seemed to solve the issue. Recently the 456 bank exhaust manifold Catalytic converter start rattling on startup for about 30 seconds and then in 3rd gear on deceleration, with some sounds like a jar of bolts rattling intermittently other time speeds and situations. A code for the rear bank O2 send or error persisted for a few thousand miles even after replacing all the sensors twice. Mechanic found a broken wire and fixed the issue with the O2 sensor, and diagnosed the Cat issue. I am keeping the car and decided to replace the cats in California, and while waiting for the ridiculously priced 4000 dollar parts to arrive the car started to overheat. At first the low oil pressure stop engine immediately and gong flashed on the display but the temp was not increasing. I drove it home about two more miles and noticed the temp begin to rise half way to the red. I pulled into a gas station and turned the car off and coolant began to spray out of a cracked reservoir seam. I towed it home, installed a new reservoir tank, bled the coolant system and then decided to drain the Mobil 1 10w30 oil and check for metal, water contamination, and debris. I found none obvious. I changed the oil using Kirkland 10w-30 replace the filter and oring, and also replaced the oil level sensor and oil pressure switch as it appeared to have oil seeping into the plug area. Both with BMW parts. After about 30 minutes of driving the low coolant level warning on the display came on. I pulled over, waited for the car to cool and checked the fluid level and it was at the bottom of the reservoir. I refilled with BMW coolant cut 50 % from the container and bled the system two more times, and then took the car out again for a test drive. It almost immediately began to heat up past the halfway normal gauge reading straight up position. Both the inlet and outlet hoses were burning hot. There were no obvious leaks. I checked the oil level on the dipstick, at the full mark. The oil was clean amber and there was no milky contamination by water and no white paste on the fill cap. I drained the coolant, checked the auxiliary coolant pump (12 volt battery to leads and it operated well), and pulled the thermostat. I applied 12 volts to the leads and in 4:58 it was fully open. I boiled water and submerged the thermostat and no movement of the thermostat occurred. Is it supposed to open by coolant temp alone? If the electronic temp switch fails will it not work? How do I check the coolant temp sensor for failure in the lower radiator hose from the pump? Could that part being inoperative cause the car to overheat? Is the thermostat actuated by both or either of the coolant temperature or electronically from the temp sensor? The coolant was clear blue in both the thermostat and in the BMW water pump. The water pump seems to be like new with the impeller and bearings showing no damage or leaks. I am unable to find the cause of the overheating and have ordered a new thermostat and water pump (high performance metal impeller). Oil pressure was 56 on start up and dropped to about 26 to 22 once warm. Revving the engine raised the pressure to 38 or 40 then the car started to overheat again. No codes are present on my OBD2 reader. Help!

My car temp guage ran right up near red while waiting for lights to change. I also had the coolant temp warning dinging away, so I drove forward (luckily the traffic lights changed) and pulled over. But as i'm heading over to the side of the road, the needle drops back to normal. Strange, as the engine didn't feel hot when I opened the hood and investigated. Haven't had it spike like that again but I suspect there's an issue with the cooling fan.

see that BC plate on the X5, you from BC?

so - for an e46 - would it be better to replace the clutch fan and the fan in front of the radiator for the electric fan setup from the manual?

Is there anything special I have to do to delete the fan clutch assembly in my E39? I'm redoing the cooling system now, but I haven't bought the new fan blade or the fan clutch. I live in Florida if that matters.

On an M52tu e46 does the fan have more than one speed?

YOU LITERALLY DIAGNOSED MY VEHICLE THANK YOU

I knew that a lot of people would disagree with you, and they did, but man am I tempted to ignore them and delete the viscous clutch and fan. That bastard fan shroud, even more. Just have to find a way to keep the hoses in place. New England, fwiw.

E39 are known for both fan clutch and aux fan to go bad, especially after 15 years or so... It's not wise to delete fan clutch, it disperses the heat very good and fast when locked (high temperature idling in city traffic). If you have only one fan and it stops working, you are busted. Two fans = double protection.

How it going Nathan, I got a mystery one for you . I have 2000 e46 323i fan clutch deleted like you suggest. But it gets hot on extremely hot days only . The electric fan works but only in lowest speed . I’ve replaced the coolant temp sensor in the lower hose & the black box sensor with known used good ones . Any ideas what could cause that? It has brand new water pump so I know the coolant is flowing good . But that fan should pop in high mode after it gets around half temp or smidge over .

Yup I had my radiator fan blow up on me at idle. Destroyed upper hose, and lower hose the Auxiliary pump was attached to, and also it destroyed that little ass expensive auxiliary pump.

At a certain point of overheat the motor is bust.

Out of dozen bmw I've owned....never had a problem with fan

nice contend - but the title - no one will find it when seaching for a over heating problem

So you can delete the clutch fan and just run the front electric fan?

Hello Nathan, checking on you... hope you are fine :)

I replaced my entire cooling system on a BMW and it turned out to be a loose pin on fan The Wire connection

I know what your talking about i have a m54 . It overheated a year ago and it just would not come right up until I got a replacement engine. I hope people listen to your advice . Don't run the engine in the red at all . It will never come right agen .

Holy shit everything makes sense

What a timeless look . E39 M5 is a beautiful car even today . 🤤🤤🤤

Oh what next clickbait? "Running without coolant will bust your engine", no shit.

That’s why Japanese cars always come first !

Ah yes I see E39s also have wasp problems 😅😂

You are engineer? Like.. clutch fan works well for 250 000km. And... dude. Dislike,. This statement is just a joke. Just get a new clutch every 10 years.