Clutch Fan Delete Help, Car starts getting hot in drive throughs.

[Rekpoint]

Hey guys, It's the middle of winter in Wisconsin but I need to tackle this right away in the spring so I can enjoy the car worry-free when I take the trip to the Tail this year.
My E46 m3 has a clutch fan delete with a SPAL fan E fan in its place using the AUX fan controller. No AUX fan either.

The car starts to creep up in temp in drive-throughs in the summer at 70+ degrees outside or if the car is not moving. If I blast the heat it usually goes down unless its 85+ outside. When stopped I cant run AC either or else the temp will also raise.
The car does NOT have a fan shroud installed and I am planning on installing the OEM one around the E fan in the spring.

Does anyone else with the same or similar setup have the same issues and have a suggestion?
Should I be messing with the AUX fan curves through ECU Worx?

[repoman89]

Does ECU Worx have an interface for changing the aux fan curve now? Cool if so. I modified mine with TunerPro, don’t think ECUWorx had anything but a checkbox for Z4M fan curves at the time which didn’t work — I have the same fan setup as you installed early last year. You should change the curve so the fan is on 100% by 85C at maximum IIRC. I might lower my threshold a little more even. My temp gets up to the middle in warm weather if the car is stopped and idling, which the OEM setup doesn’t do.

You might need a fresh OEM radiator as well with this setup if yours is getting old.

[Mr.wReckless]

From my understanding the OEM AUX fan won't have the ability to run the e-fan at full capacity. You're better off getting a proper controller IMO. I did run your setup for a summer, but the temps up here in the arctic aren't that great even during summer.

I doubt the fan shroud will make a massive difference. You're probably better off blowing out your radiators from debris etc too. Also, to my understanding, not having the front pusher fan + A/C isn't a good combo as when you're low on speed there's not enough airflow to cool down the A/C heat exchanger, so you're running a risk of dumping your a/c gass to atmosphere due to the heat leading to over-pressure.

My advice is clear out your radiators, alternatively get a new one or an aftermarket upgrade, as well as fit a proper fan controller.

Regards

[repoman89]

From my understanding the OEM AUX fan won't have the ability to run the e-fan at full capacity. You're better off getting a proper controller IMO. I did run your setup for a summer, but the temps up here in the arctic aren't that great even during summer.

Source for this? My understanding is the aux fan controller is perfectly capable of running a 100% duty cycle at 12V. If that caused an overcurrent / overpower condition on that wiring the aux fan fuse would blow. That certainly doesn’t happen on my car.

[Rekpoint]

Does ECU Worx have an interface for changing the aux fan curve now? Cool if so. I modified mine with TunerPro, don’t think ECUWorx had anything but a checkbox for Z4M fan curves at the time which didn’t work — I have the same fan setup as you installed early last year. You should change the curve so the fan is on 100% by 85C at maximum IIRC. I might lower my threshold a little more even. My temp gets up to the middle in warm weather if the car is stopped and idling, which the OEM setup doesn’t do.

You might need a fresh OEM radiator as well with this setup if yours is getting old.

I am probably misinformed about ECU Worx. Ill have to look into TunerPro. Nice to see that you have had success with this setup. Are you running a fan shroud?

Radiator was replaced around 20k ago. I AM replacing my thermostat because it got stuck last summer. But that was also replaced with the radiator.

[Rekpoint]

From my understanding the OEM AUX fan won't have the ability to run the e-fan at full capacity. You're better off getting a proper controller IMO. I did run your setup for a summer, but the temps up here in the arctic aren't that great even during summer.

I doubt the fan shroud will make a massive difference. You're probably better off blowing out your radiators from debris etc too. Also, to my understanding, not having the front pusher fan + A/C isn't a good combo as when you're low on speed there's not enough airflow to cool down the A/C heat exchanger, so you're running a risk of dumping your a/c gass to atmosphere due to the heat leading to over-pressure.

My advice is clear out your radiators, alternatively get a new one or an aftermarket upgrade, as well as fit a proper fan controller.

Regards

I have been looking into the possibility of going with a standalone fan cotroller. If I go that route I will convert the aux fan controller back to the Aux fan and run the Efan with the Efan controller.

[repoman89]

I am probably misinformed about ECU Worx. Ill have to look into TunerPro. Nice to see that you have had success with this setup. Are you running a fan shroud?

Radiator was replaced around 20k ago. I AM replacing my thermostat because it got stuck last summer. But that was also replaced with the radiator.

Radiator is probably fine then. I’d start with the fan curve. Mine creeped up too before I messed with it IIRC. This might help: https://nam3forum.com/forums/forum/s...curve-location

I am not running the shroud or the two plastic air director things. Radiator and cooling system is original but the car only has 45k miles.

[Mr.wReckless]

Source for this? My understanding is the aux fan controller is perfectly capable of running a 100% duty cycle at 12V. If that caused an overcurrent / overpower condition on that wiring the aux fan fuse would blow. That certainly doesn’t happen on my car.

I'm not sure I can find a quote. Like I said it's only to my understanding, and perhaps born out of what could strictly be internet hearsay, but before I ditched the AUX/clutch fan combo for a single Mishimoto I did a whole bunch of googling and seemed to find several M3 specific forum statements supporting this. From what I remember the standard AUX fan controller runs off/med/high speeds, but even the "high speed" isn't pushing enough to max out the capacity of an aftermarket electric fan, but this might just cook down to an urban myth :/

Regards

[IMOLA3]

If you're going to remove your clutch fan, you should just run the stock aux fan and make sure the rest of your cooling system is refreshed. A lot of these aftermarket SPAL fans and the like aren't running proper shrouds or pulling enough CFM to be any better than the stock aux. I've run with the aux fan only in 115F summer heat with very little (if any) change in temp while both idling and cruising. It seems like people have more issues with all these other electric fans. If it ain't broke...

[sapote]

From what I remember the standard AUX fan controller runs off/med/high speeds, but even the "high speed" isn't pushing enough to max out the capacity of an aftermarket electric fan, but this might just cook down to an urban myth :/

The DME only sends the PWM fan speed command signal, which has 90% duty cycle as max value (below 10% and above 90% are special values for diagnosis purpose). How fast or powerful the fan running is depending on the fan motor, and should not be the AUX fan controller as it will output 90% of the full 14v supply.

[Mr.wReckless]

The DME only sends the PWM fan speed command signal, which has 90% duty cycle as max value (below 10% and above 90% are special values for diagnosis purpose). How fast or powerful the fan running is depending on the fan motor, and should not be the AUX fan controller as it will output 90% of the full 14v supply.

https://forums.m3cutters.co.uk/threads/m3-aux-fan-switch-temp-rating.109393/

Here's what I found after a quick search. Back in the day I seem to recall finding more around this, but like I said, it might all be hearsay. Anyways the link shows the DME having 2 maps for the AUX fan, one of which being speed related. Now whether that will affect the cooling is debatable, as I imagine doing 100mph you're pushing plenty of air through the radiators anyways.

Regards

[jet_dogg]

I ain't the smartest man in the world but isn't that what happens when you do stuff like this? What about prolonged elevated coolant temps over the summers?

That's like saying I put 87 in my car and now it runs like shit. The cooling system is one of those things I wouldn't personally mess with nor would I buy a car from someone who has.

[repoman89]

?

That's like saying I put 87 in my car and now it runs like shit.

It couldn’t be anything less like that.

Really easy to get it to work right and run well but needs simple DIY tuning of literally one map in the DME. Hope you don’t run anything but the stock BMW engine tune with that logic.

edit: sorry dogg, this came off as douchier than intended rereading it. But the point stands!

[repoman89]

https://forums.m3cutters.co.uk/threads/m3-aux-fan-switch-temp-rating.109393/

Here's what I found after a quick search. Back in the day I seem to recall finding more around this, but like I said, it might all be hearsay. Anyways the link shows the DME having 2 maps for the AUX fan, one of which being speed related. Now whether that will affect the cooling is debatable, as I imagine doing 100mph you're pushing plenty of air through the radiators anyways.

Regards

More detail than you want to know about how it works: https://github.com/saildot4k/MSS54-X...Aux-Fan-Speeds

[Icecream]

If you're going to remove your clutch fan, you should just run the stock aux fan and make sure the rest of your cooling system is refreshed. A lot of these aftermarket SPAL fans and the like aren't running proper shrouds or pulling enough CFM to be any better than the stock aux. I've run with the aux fan only in 115F summer heat with very little (if any) change in temp while both idling and cruising. It seems like people have more issues with all these other electric fans. If it ain't broke...

Seems alot of people have issues with aftermarket fans. I ran without a fan for a year in LA heat and traffic without a problem, got warm on a few occasions (not near red) but nothing to cause me to lose sleep. Removed it cause the old one was old and ready to Crack. Never got around to replacing. I also don't have one on an m coupe I've been toying with, doesn't mind it either. I keep having to do maintenance that requires fan removal and just got sick of it. I don't know.