Fan Delete and Now Overheating

[ShelbyGT500]

Never, ever take the fan off. Asking for trouble on any car.

So far so good. If it survives August in Oklahoma then this delete is great. From the reviews on this delete it seems safe. It may be bad in stop/go traffic like at Houston & LA but traffic isn't horrible in OKC.

[gmushial]

So far so good. If it survives August in Oklahoma then this delete is great. From the reviews on this delete it seems safe. It may be bad in stop/go traffic like at Houston & LA but traffic isn't horrible in OKC.

Mine survived 116degF in town driving here in Redding this summer and with zero issues... though I did have my phone tied to the OBD port reading the actual temps, just to make sure... but I suspect, once you get the water into your system, and the air out, you'll be good to go.

[ShelbyGT500]

Randy-
Are you running 100% distilled water with water wetter?

[danomite]

Never, ever take the fan off. Asking for trouble on any car.

...as opposed to leaving it on the car so that it can explode? Thereby destroying your hoses, belts, radiator, shroud, hood, etc. #seemslegit

[deni2s]

...as opposed to leaving it on the car so that it can explode? Thereby destroying your hoses, belts, radiator, shroud, hood, etc. #seemslegit

Just replace it once every ten years when it becomes brittle and no worries.

[LannVouivre]

Never, ever take the fan off. Asking for trouble on any car.

Randy rf's Z3 hasn't had a clutch fan in ages, and despite his location in Florida, his Z3 hasn't ever cared.

I live in Texas, removed the clutch fan. Despite 100°F+ weather, I don't even remotely have overheat issues even while idling parked. I pulled the clutch fan on my fiance's 525, and it also doesn't have issues with overheating.

The auxiliary fans on these cars are completely adequate alone, so long as the rest of the system (including aux fan) is working correctly and maintained. The clutch fan is just something BMW was having trouble letting go of. Its only purposes on these cars are to increase wear on the water pump bearings and seals, and possibly eventually explode and destroy your hood and anything else the debris hit. It's literally only there because BMW had always had clutch fans before and I guess they just couldn't bear to break tradition.

[Tim95M3]

No sense in starting this argument over again. And again... You'll never sway the opinion of some that think "BMW designed it and put it there for a reason". That's why they don't modify any other part of the car, yeah?

[rf900rkw]

Fan delete is a well established mod for this generation, Z3, E36, E39, and E46 (those that aren't fan delete from the factory) all benefit from removing the mechanical fan. At this point those that argue against it, especially those spouting a blind "but you can't do that", are doing so out of ignorance. Or they just enjoy being a troll. Either way, ignore them.

[raubritter]

I deleted mine 5 years ago and despite the hellish Texas heat I haven't had any abnormally high temperatures. The aux fan does come on occasionally and the system works well enough that I never seem to get to the high temp trigger on the fan switch (which is when the SPAL puller fan I installed is wired to come on). It's nice having the SPAL as a backup, but it never has to come on as long as everything is working right.

[mikerob97]

Fan delete is a well established mod for this generation, Z3, E36, E39, and E46 (those that aren't fan delete from the factory) all benefit from removing the mechanical fan. At this point those that argue against it, especially those spouting a blind "but you can't do that", are doing so out of ignorance. Or they just enjoy being a troll. Either way, ignore them.

I relocated my coolant reservoir to where the European M3s have theirs located. The system is essentially self bleeding since you now fill from highest point in the system. take a look at Realoem.com to get an idea of how the plumbing is routed. I ran this system in my car for over many years - until I sold the car.

[cleanerPA]

...as opposed to leaving it on the car so that it can explode? Thereby destroying your hoses, belts, radiator, shroud, hood, etc. #seemslegit

Rather than being dramatic about it, just replace it. I replaced the fan clutch and the fan on my car as preventative maintenance.

[Vintage42]

... The clutch fan... possibly eventually explode and destroy your hood and anything else the debris hit...

... I replaced the fan clutch and the fan on my car as preventative maintenance.

Like, a new fan is less likely to explode than an old fan.

[cleanerPA]

Like, a new fan is less likely to explode than an old fan.

Well yes. Heat cycling weakens plastic.


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[LannVouivre]

Why would I waste money ($60+) on replacing the clutch fan when it's obviously completely unnecessary and just kind of a hassle to deal with? If I don't need the clutch fan when I'm idling in 110°F+ weather, I've got no motivation to take it from its happy retirement life of decorating a shelf.

[ShelbyGT500]

I relocated my coolant reservoir to where the European M3s have theirs located. The system is essentially self bleeding since you now fill from highest point in the system. take a look at Realoem.com to get an idea of how the plumbing is routed. I ran this system in my car for over many years - until I sold the car.

I will definitely look into this. One question. Is the coolant reservoir tanks on our cars pressurize? I assume so after reading some of the replies. I was just curious from brainstorming with some friends

[rf900rkw]

It is properly called the expansion tank. Not only is it pressurized, it sets the system pressure by the volume of the air column in it.

The side story here is overfilling the tank is a very bad thing. Normal system pressure is 16-18 psi. Remove the air column by over filling and system pressure will be regulated too 30 psi by the safety valve.

[danomite]

Rather than being dramatic about it, just replace it. I replaced the fan clutch and the fan on my car as preventative maintenance.

Being dramatic about it? How about rather than being passive aggressive towards someone who had their fan detonate and do "all of the above", costing me several grand worth of repairs (again, not being dramatic...hoods and good paintwork are expensive), you think about what "benefit" that viscous fan provides. The answer is NONE.

Well yes. Heat cycling weakens plastic.

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Not any more than bad craftsmanship. But now you're probably gonna tell us that new parts will never fail right away.

There's a reason why BMW omitted the viscous fan on all models following ours....guess why that is?

[cleanerPA]

Being dramatic about it? How about rather than being passive aggressive towards someone who had their fan detonate and do "all of the above", costing me several grand worth of repairs (again, not being dramatic...hoods and good paintwork are expensive), you think about what "benefit" that viscous fan provides. The answer is NONE.



Not any more than bad craftsmanship. But now you're probably gonna tell us that new parts will never fail right away.

There's a reason why BMW omitted the viscous fan on all models following ours....guess why that is?

I guess you can laugh at me when my fan blows up.


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[deni2s]

1) Am not sure people from "hot" places advocating viscous clutch fan delete are actually driven in drive & stop traffic in their deserts Just idling is nothing compared to that.
2) Anyway relying on just aux fan doesn't sounds right to me. There should always be backup (which is aux fan in normal case).
3) Aux fan kicks in already too late - when very hot temp water from engine has already reached radiator and mix of cooled/still hot water is too hot. Switch is inside radiator, not the engine.

My plan is to replace clutch fan with spal puller on one car, so aux fan will still be there for a backup. Other car will be just fine with fresh clutch fan. So far in my friends experience (lots of e36/e46 owners) that happened only when something wasn't fixed well and got in way of fan.

[BimmerBreaker]

I drove mine in stop and go traffic with no fan and live in the hottest city in the US

[ptony101]

You don't have any coolant in the block. If you filled it using a youtube vid, you did it wrong. If you filled it using any instructions that tell you to start the engine before the system is totally full, you did it wrong. Cold engine. Take the upper hose off, and stick it on the thermostat housing pointed up. Use this new point to pour coolant directly into the engine. Keep pouring until coolant runs out of the open radiator neck. Reinstall hose. Finish topping up, squeezing hoses to burp the last bit of air out. Put the cap on, start it up. Note that no where in here did I mention the bleeder; it's a waste of time.

Hey Randy,

Will this work on an M54 engine? Remove the upper radiator hose at the radiator and pour coolant into the thermostat / engine block via the hose?

Thx.

[gmushial]

1) Am not sure people from "hot" places advocating viscous clutch fan delete are actually driven in drive & stop traffic in their deserts Just idling is nothing compared to that.
2) Anyway relying on just aux fan doesn't sounds right to me. There should always be backup (which is aux fan in normal case).
3) Aux fan kicks in already too late - when very hot temp water from engine has already reached radiator and mix of cooled/still hot water is too hot. Switch is inside radiator, not the engine.

My plan is to replace clutch fan with spal puller on one car, so aux fan will still be there for a backup. Other car will be just fine with fresh clutch fan. So far in my friends experience (lots of e36/e46 owners) that happened only when something wasn't fixed well and got in way of fan.

Stop and go driving in over 110degF weather this summer: no issues... [had my phone connected to the OBD port to monitor the actual numbers... 204F was the highest I saw].

And, you might go back and read up on Randy's posts as to how the cooling systems actually work... but the aux fan doesn't come on "when it's too late".

[danomite]

I guess you can laugh at me when my fan blows up.


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You can bet your ass I'll be the first person to say "I told ya so"...then I'll probably continue on about how you could've saved time and money by leaving that uneccessary fan off of the car.

1) Am not sure people from "hot" places advocating viscous clutch fan delete are actually driven in drive & stop traffic in their deserts Just idling is nothing compared to that.
2) Anyway relying on just aux fan doesn't sounds right to me. There should always be backup (which is aux fan in normal case).
3) Aux fan kicks in already too late - when very hot temp water from engine has already reached radiator and mix of cooled/still hot water is too hot. Switch is inside radiator, not the engine.

My plan is to replace clutch fan with spal puller on one car, so aux fan will still be there for a backup. Other car will be just fine with fresh clutch fan. So far in my friends experience (lots of e36/e46 owners) that happened only when something wasn't fixed well and got in way of fan.

deni2s,

1) We've had the hottest summer in the history of LA this past year...plenty of days that were almost forty degrees Celsius, and I'm sure you can imagine how bad LA traffic is. I think we're the kings of stop-n-go! That being said, I haven't had ANY issues since removing my fan...and the aux fan only comes on rarely.

2) All of the BMW's produced/built after ours only have an electric fan. Our aux fan is probably the most efficient fan possible for our cars, and there's plenty of real-world experience proving that removing the viscous fan is no problem, and actually removes the ticking time bomb.

3) The aux fan is activated when the water at the outlet side of the radiator reaches the trigger temp of whichever switch you have installed (I have an 88C degree switch installed). The reason that you have hotter water at the outlet side is probably because you're not moving (forcing air through the radiator to cool the water), so as long as your aux fan works it will cool the water and provide cooler water to the engine. Thermostat controls the flow of water, not the radiator. My car never runs above 104C, and most of the time I'm around 92C or below. Our engines aren't in the danger zone until over 115C. My car ran at 92C when I had the viscous fan installed, and still runs at that temp now...because the thermostat keeps it there. So, that aux fan doesn't kick in too late...it kicks in the same "time" as it always would, even if the viscous fan was still installed.

If you install a SPAL puller, you'll be partially blocking the flow of air through the radiator (the SPAL fan won't be spinning like the OEM viscous fan), and you'll have to build/buy a shroud that the fan can mount to, which is sealed around the edges. All unnecessary, time-consuming, and it's more money you'll be spending.

PS - I have a brand new SPAL puller fan with relay and everything, if anybody is looking for one. It's the 2024 cfm curved-blade (quieter) one. I never installed it, because the stock OEM aux fan works 10 times better!!! Model# 30102049

[LannVouivre]

Considering that my Z3 is actually my daily, I can honestly say that I have indeed driven it in stop and go traffic. Probably nothing like as much traffic as in Phoenix, though.

[campy1951]

Can someone explain the fan delete and should I do it on my 2001 3.0? Is there a video on how it's done?