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E39 (1997 - 2003)
The BMW 5-Series (E39 chassis) was introduced in the United States as a 1997 model year car and lasted until the 2004 when the E60 chassis was released. The United States saw several variations including the 525i, 528i, 530i and 540i. -- View the E39 Wiki

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Old 07-09-2011, 03:01 AM
Burning2nd's Avatar
Burning2nd Burning2nd is offline
Under the lift arms
Location: Under the lift arms
Join Date: Aug 2010
Posts: 8,197
Mein Auto: E39 540, E36 328is, E83x3
Originally Posted by bmw_lover85 View Post
Thank you Burning2nd. I don't want to evacuate the system... Is that ok?
I thought I can let some pressure out and then put some oil. My AC is cold... It just make knocking noise from the compressor... It sounds like an impact gun but a little bit lower in sound.
chances are your compressor is on its way out, If you hear a knocking noise already.

technically you put the oil in first.. then the amount of freeon,

when topping off a system the little cans work fine...

I have no idea what will happen if you put oil in a changed system... and ive never heard a compressor knock....Only seen them seize...

compressor for the 5's run like what 500 bucks?
Specializing In BMW, Audi, Mercedes Benz ,Volkswagen, Volvo

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Old 04-17-2013, 06:13 AM
bmwmanz2 bmwmanz2 is offline
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Mein Auto: E39 528i
For the static reading (car running AC off) you need a Pressure Temperature chart or app by DuPont. This will show you what your gauges should be reading. Ie. ambient temperature is 90* the gauges should read 104.3*. For a Dynamic reading (car on and AC running) on your AC Manifold gauges on the low side should read between 25-45 and the high side should read 100-150* above ambient temperature. Ie. 90* ambient temp high side should read 190-240* on the high side. The PAG oil can either be injected via a recovery machine or taking the compressor off and filling it to the correct specs taking off the back plate of the compressor. As for a noisy compressor, this usually means your compressor is bad and has run low on oil. Hope this helps a little guys. Have a great day!
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Old 04-17-2013, 06:50 PM
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bluebee bluebee is offline
Seek to understand,^Value
Location: San Jose, California
Join Date: Mar 2008
Posts: 25,236
Mein Auto: 02 BMW 525i M54 auto 130K
I'm gonna cross reference this thread to the canonical AC threads so that this information isn't lost.

- How to learn about (1) and set up your air conditioning (1) (2) & how to refill your A/C system for $20 (1) (2) (3) (4) & where to find your low pressure aircon recharge port (1) & what refrigerant PAG oil to use (1) (1) & R134a conversion information (1) (2) how to measure A C temperature (1)
Please read the suggested threads and add value, either by pictures or by descriptions, so the next person stands on your shoulders.
See also: E39 Bestlinks & How to easily find what you need
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