Ventilation Fan Speed

bfi2906 · 08-24-2009, 06:20 PM

Is it just my car, or is it normal, for the vent fan speed to fluctuate quite widely with the engine speed.

I have it set on "Auto", with A/C off. I've noticed that the fan will increase quite a deal as revs rise, and drop back with the revs. I understand the principal of the "Auto" setting, as I'm familiar with it from previous BMW's. But this fluctuation with engine speed is new to me.

In previous cars, the "Auto" function would work at whatever speed it needed to achieve the set temperature, regardless of engine speed.

This isn't a big deal, but it is kind of annoying in city traffic in Sydney, where the reves are up and down like "the proverbial".

Anyone else seeing this?

TimMc · 08-24-2009, 09:07 PM

Doesn't sound right to me. I don't have this issue.

harpoon · 08-24-2009, 09:14 PM

Yeh mine does that. Try playing with the recirculation setting. I think mine only does that when its on the auto recir setting?

takahashi · 08-24-2009, 09:22 PM

Don't have that problem. I don't think my aircon is tied to my alternator belt... Andrew ripped mine belt in back in May when the car is 4 weeks ago - ... haha that was a long story

05C4R · 08-25-2009, 12:09 AM

mine changes speed randomly but not in time with the motor, someone in another thread a while ago questioned their dealer and was told its normal, can't remember who.

AussieRacer · 08-25-2009, 03:37 AM

My old 120i used to go quiet and loud for no reason. My 135i doesn't.... So who knows.

Breville · 08-25-2009, 06:14 AM

This is a widely known issue

spastic fan or the like as mine does the same..

bfi2906 · 08-25-2009, 08:14 AM

Thanks guys. As long as it's happening for others, then I'm happy it's not a sign of a malfunction or something about to go wrong.

I might quiz the dealer next time I take it in - just to get an official answer (and to see what kind of entertaining explaination they come up with)

sparoz · 08-25-2009, 08:54 AM

Spastic fan is a malfunction - all they need to do is to change the transistor unit. Know problem on the e46, but I assume it is a problem on newer cars as well? My fan is fine on the 120d, 125i and 135i. Hope it helps.

bfi2906 · 08-25-2009, 10:35 PM

Thanks Sparoz - with your info, I'll ask my question of the dealer in a differnet way. And a different expectation of their response.

Cheers.

Breville · 08-27-2009, 04:02 AM

I didn't know it was fixable, doesn't bother me but I'll put in on the list for my service.

sparoz · 08-27-2009, 08:39 AM

Quote:

Originally Posted by sparoz

Spastic fan is a malfunction - all they need to do is to change the transistor unit. Know problem on the e46, but I assume it is a problem on newer cars as well? My fan is fine on the 120d, 125i and 135i. Hope it helps.

Just want to clarify that the transistor was a known problem for the E46.

. It only seems to fail after 2-3 years. So, if it is the same problem with the 1er - at this early age - it's a little bit of a worry.

Lone ranger · 08-28-2009, 11:29 PM

I would think if you want to uae Auto you have to have A/C on. If not, just fan alone wont be able to get the temp down in the sun.

08-24-2009, 06:20 PM	#1
bfi2906 Captain 35 Rep 685 Posts Drives: 135 Coupe Join Date: Aug 2008 Location: Sydney iTrader: (0)	Ventilation Fan Speed Is it just my car, or is it normal, for the vent fan speed to fluctuate quite widely with the engine speed. I have it set on "Auto", with A/C off. I've noticed that the fan will increase quite a deal as revs rise, and drop back with the revs. I understand the principal of the "Auto" setting, as I'm familiar with it from previous BMW's. But this fluctuation with engine speed is new to me. In previous cars, the "Auto" function would work at whatever speed it needed to achieve the set temperature, regardless of engine speed. This isn't a big deal, but it is kind of annoying in city traffic in Sydney, where the reves are up and down like "the proverbial". Anyone else seeing this?
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08-24-2009, 09:07 PM	#2
TimMc Lieutenant Colonel 44 Rep 1,883 Posts Drives: E90 M3 Join Date: Aug 2008 Location: Brisbane, Australia iTrader: (0)	Doesn't sound right to me. I don't have this issue.
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08-24-2009, 09:14 PM	#3
harpoon Lieutenant 12 Rep 440 Posts Drives: e92 M3 Join Date: May 2008 Location: Syd iTrader: (1)	Yeh mine does that. Try playing with the recirculation setting. I think mine only does that when its on the auto recir setting? __________________ E92 M3
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08-24-2009, 09:22 PM	#4
takahashi Retired trackie 36 Rep 1,527 Posts Drives: 1///M Join Date: Jul 2008 Location: Melbourne, Australia iTrader: (0)	Don't have that problem. I don't think my aircon is tied to my alternator belt... Andrew ripped mine belt in back in May when the car is 4 weeks ago - ... haha that was a long story __________________ TAKA 一仔BLOGブログ: BMW 1 series M 2011! Delivered 18/11/11.
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08-25-2009, 12:09 AM	#5
05C4R Major 62 Rep 1,147 Posts Drives: M3 Join Date: Jul 2008 Location: sydney iTrader: (0)	mine changes speed randomly but not in time with the motor, someone in another thread a while ago questioned their dealer and was told its normal, can't remember who.
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08-25-2009, 03:37 AM	#6
AussieRacer Major 24 Rep 1,058 Posts Drives: 2008 135i Join Date: Apr 2008 Location: Aust iTrader: (0)	My old 120i used to go quiet and loud for no reason. My 135i doesn't.... So who knows. __________________ Current: 135i Auto, Le Mans Blue - w/ Bridgestone RE-11 rears, GP Thunder 7500k angels, & "golf tee" mod plus a few M3 suspension bits and pieces...
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08-25-2009, 06:14 AM	#7
Breville Scum in the sun 30 Rep 938 Posts Drives: 135i Coupe TiAg Join Date: Sep 2008 Location: Syndey iTrader: (0) Garage List 2008 135i Coupe [0.00]	This is a widely known issue spastic fan or the like as mine does the same.. __________________ One should love animals. They are so tasty.
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08-25-2009, 08:14 AM	#8
bfi2906 Captain 35 Rep 685 Posts Drives: 135 Coupe Join Date: Aug 2008 Location: Sydney iTrader: (0)	Thanks guys. As long as it's happening for others, then I'm happy it's not a sign of a malfunction or something about to go wrong. I might quiz the dealer next time I take it in - just to get an official answer (and to see what kind of entertaining explaination they come up with)
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08-25-2009, 08:54 AM	#9
sparoz Brigadier General 191 Rep 4,848 Posts Drives: VO 1///M; Macan Turbo Join Date: Jun 2008 Location: Sunshine Coast iTrader: (0)	Spastic fan is a malfunction - all they need to do is to change the transistor unit. Know problem on the e46, but I assume it is a problem on newer cars as well? My fan is fine on the 120d, 125i and 135i. Hope it helps. __________________ Macan S Diesel - Carrera White Macan Turbo - White 1///M - Valencia Orange
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08-25-2009, 10:35 PM	#10
bfi2906 Captain 35 Rep 685 Posts Drives: 135 Coupe Join Date: Aug 2008 Location: Sydney iTrader: (0)	Thanks Sparoz - with your info, I'll ask my question of the dealer in a differnet way. And a different expectation of their response. Cheers.
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08-27-2009, 04:02 AM	#11
Breville Scum in the sun 30 Rep 938 Posts Drives: 135i Coupe TiAg Join Date: Sep 2008 Location: Syndey iTrader: (0) Garage List 2008 135i Coupe [0.00]	I didn't know it was fixable, doesn't bother me but I'll put in on the list for my service. __________________ One should love animals. They are so tasty.
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08-28-2009, 11:29 PM	#13
Lone ranger New Member 3 Rep 27 Posts Drives: 125i Join Date: Oct 2008 Location: Australia iTrader: (0)	I would think if you want to uae Auto you have to have A/C on. If not, just fan alone wont be able to get the temp down in the sun.
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