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2.5L M50TU

Printed From: Bavarian-Board.co.uk - BMW Owners Discussion Forum
Category: Technical & Model Specific Forums
Forum Name: BMW 3 Series
Forum Discription: This forum will deal with any issues on the BMW 3 Series (E21, E30, E36, E46, E90, E91 & E92)
URL: http://www.bavarian-board.co.uk/forum_posts.asp?TID=4629
Printed Date: 03-June-2024 at 10:47


Topic: 2.5L M50TU
Posted By: 325ism50
Subject: 2.5L M50TU
Date Posted: 18-December-2003 at 15:44

Hey guys!!

Is there anyone here with experience of aircond? My engine runs at 700 rpm but when I turn on the aircond the RPM drops to 500 RPM and the car make a vibration then afterwards it goes back to 700 RPM.

What I have changed is a new idler valve, throttle body, ecu. I have checked the wiring from the aircond to the ecu. My car doesn't have a catalytic converter. Can this be the problem? My car does have an oxygen sensor.

Thanks in advance



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oklah


Replies:
Posted By: Webdunk
Date Posted: 18-December-2003 at 16:28
Sounds pretty normal to me - the A/C loads the car's electrical system, causing a temporary drop in revs before it recovers. Suspect this may not actually be a problem

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Posted By: Magnum Man
Date Posted: 18-December-2003 at 17:04

I would agree.

The reduction in revs is caused by the air conditioning compressor being engaged as you swith on the ac on, with a resultant a load of several horse power being demanded of the engine...hence the dip & recovery you experience.

One other key point is that the air con won't work if the outside temp is below 4 centigrade,this ensures that things don't freeze up.

Your switches will glow as per usual when the buttons are pressed but the compressor will not engage.

Hope this helps.



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Ice Cream Boy

Posted By: daddy cool
Date Posted: 18-December-2003 at 19:31

it might be worth pointing out , if u dont allready know ! having air conditioning  switched on can considerably reduce your fuel economy

 Only wanted to point it out incase u werent aware .



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e30 2.7 cab
e30 325i
e30 325 sport
e30 318 touring
e28 m5
e28 m535
e34 m5
e39 540
e36 318ti (green)
e36 318ti (mauve)

Posted By: 325ism50
Date Posted: 19-December-2003 at 14:04

 

Hi guys - I am very happy now. My problem is sorted out. It was the wrong alternator. It should have been 140 amp not 80 amp (that's for 1.8 litre and mine is 2.5).

Thanks to all who wrote in with advice



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oklah


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