[moderat0r]

hi,
323i Year 2011 SEDAN E90 (MUE) N52K ENGINE

I am thinking to service air conditioner and I am not sure where to start, the reason I want to do this because at 16C its not that efficient, takes a lot of time to cool down the car.
I was thinking to check the air conditioner gas pressure with the guage but I dont know which type of refrigerant goes into the AC.
Also if you have other tips for me while working on AC, please let me know.

thankyou

[Tambohamilton]

It's on a sticker on the underside of the hood/bonnet. 90% sure it's r134a.

I'd take it to someone with proper equipment to fully evacuate, measure and refill the system. Measuring the pressure of what's in there is not sufficiently accurate.

[NZE90]

^^^^ what he said

[whyzee125]

It's R134A. Get a can with the gauge on it and it's a 5 min job.

[Andystobbs]

Let a shop do it properly by vacuuming the system

[Twix]

If you need refrigerant, you need to fix the leak first.

[Tambohamilton]

Originally Posted by Twix

If you need refrigerant, you need to fix the leak first.

Not necessarily; all systems leak gradually, so it's expected to need a top-up if it's been a while.

[BRG_N54]

Here's a great DIY video that describes the process quite thoroughly. You will need some special equipment, but can use on any car afterward.

[gbalthrop]

Originally Posted by moderat0r

... 323i Year 2011 SEDAN E90 (MUE) N52K ENGINE [Canada]
... I was thinking to check the air conditioner gas pressure with the gauge but I dont know which type of refrigerant goes into the AC...

Perhaps you can educate us on WHEN Canada went to R12a conversion of R-134a systems, and/or prohibited sale of R-134a
12-oz. cans. See the label under the front of hood for factory refrigerant: type & total charge. I attach ScreenPrint of my Label
(3/2007 build 328xi, US market) for comparison. If you still had R-134a in the system, AND you could get a 12-oz R-134a can,
you could add charge to system yourself simply using a Pressure/ Temp chart such as the following:
https://www.rechargeac.com/how-to/ac...ressure-chart/

I know NOTHING about R12a, such as if there is a conversion process, the relative weight of charge, R-134a vs. R12a,
or whether there is ANY reliable Pressure/ Temp Chart available on the Web. I also know NOTHING about CA Law.

If you learn anything about those subjects, please enlighten the rest of us, so we don't provide ignorant replies.
George

[simon]

Originally Posted by Tambohamilton

Not necessarily; all systems leak gradually, so it's expected to need a top-up if it's been a while.

No refrigerant system should ever leak, gradually or not.

[JB20DGM]

Originally Posted by gbalthrop

Perhaps you can educate us on WHEN Canada went to R12a conversion of R-134a systems, and/or prohibited sale of R-134a
12-oz. cans. See the label under the front of hood for factory refrigerant: type & total charge. I attach ScreenPrint of my Label
(3/2007 build 328xi, US market) for comparison. If you still had R-134a in the system, AND you could get a 12-oz R-134a can,
you could add charge to system yourself simply using a Pressure/ Temp chart such as the following:
https://www.rechargeac.com/how-to/ac...ressure-chart/

I know NOTHING about R12a, such as if there is a conversion process, the relative weight of charge, R-134a vs. R12a,
or whether there is ANY reliable Pressure/ Temp Chart available on the Web. I also know NOTHING about CA Law.

If you learn anything about those subjects, please enlighten the rest of us, so we don't provide ignorant replies.
George

It's the other way around, R12 was phased out of most automotive use during the 1992-1994 timeframe and shifted over to R134a. And much more recently we've got 1234-yf that came into play, but that would probably not encompass any of the E9x platforms. R134a and the 1234yf are available over the counter in the US.

[gbalthrop]

Originally Posted by JB20DGM

It's the other way around, R12 was phased out of most automotive use during the 1992-1994...

Remedial Reading 101:

R12a

See link below for information. R12a is NOT your grandfather's R12:
https://www.google.com/search?q=r12a...hrome&ie=UTF-8
George

[TheMidnightNarwhal]

Originally Posted by JB20DGM

It's the other way around, R12 was phased out of most automotive use during the 1992-1994 timeframe and shifted over to R134a. And much more recently we've got 1234-yf that came into play, but that would probably not encompass any of the E9x platforms. R134a and the 1234yf are available over the counter in the US.

In Canada I can only get R12a locally which should work on r134a systems

[JB20DGM]

Originally Posted by TheMidnightNarwhal

In Canada I can only get R12a locally which should work on r134a systems

Fair enough, since R134a is still generally available in the US I never had a reason to look for anything else.

Something that gets overlooked often as a source of "small" leaks tends to be the schrader valves in the test ports. Since when you hook a gauge set up to them they're open, and open when you pull a vacuum on them to recover/refill.

[Twix]

Originally Posted by Tambohamilton

Not necessarily; all systems leak gradually, so it's expected to need a top-up if it's been a while.

No they don’t. Systems are fully sealed. Refrigerant doesn’t just fall out. I have systems with 1000s of lbs of refrigerant that still have the original charge after years of service.

If you’re low, you need to find the leak. Period.

[Tambohamilton]

Originally Posted by Twix

No they don’t. Systems are fully sealed. Refrigerant doesn’t just fall out. I have systems with 1000s of lbs of refrigerant that still have the original charge after years of service.

If you’re low, you need to find the leak. Period.

BMW state a loss of up to 30g per year is permissible.

[NZE90]

Originally Posted by Tambohamilton

BMW state a loss of up to 30g per year is permissible.

Yea, you are correct there. I've seen that in ISTA.

[gbalthrop]

Originally Posted by Tambohamilton

BMW state a loss of up to 30g per year is permissible.

Quite True: See attached ISTA ScreenPrints of ISTA Repair Procedure.
"Sealed" is a "relative term". What we "SEE" as a closed system is actually a bunch of molecules with a lot of
space for things to get out, depending upon molecular size, pressure, etc.

One of the perceived "Issues" with R-134a when it replaced R-12 in 90's (in US) was that it's "molecular size" was smaller
than R-12, and that it would leak faster than R-12 in the SAME system. US systems used to include a LOT of rubber hoses.
Even when those hoses are replaced by steel lines, there are still o-rings at component attachments/ fittings,
and seal on compressor shaft, etc.

So SOME small amount of Refrigerant leakage is EXPECTED. BMW has prescribed a limit of an AVERAGE of 30 grams
(of 590 gram charge) per year over a 5-year period. SLOW leaks, < 30g/yr do NOT suggest a need to add Refigeration Oil.
Larger Leaks are deemed to require "topping up" of refrigeration oil.

This is BMW Procedure, NOT mine, so if you don't agree, you're welcome to express your views -- just don't attack me.

Any opinions on evacuation & recharge every X years to remove water absorbed by R-134a and other corrosive agents?
George

[NZE90]

Originally Posted by simon

No refrigerant system should ever leak, gradually or not.

Not true. See above.

[oVeRdOsE.]

Originally Posted by Twix

No they don’t. Systems are fully sealed. Refrigerant doesn’t just fall out. I have systems with 1000s of lbs of refrigerant that still have the original charge after years of service.

If you’re low, you need to find the leak. Period.

Yes they do.

it's simple physics n' wear, and also working in that field.

However, most of the time it's a leak from a defective part. E90 tend to leak in the passenger wheel well, since the alu line get near the opening.

The goal is to determine the leak rate. A a/c system will work on a P set point +/- few PSI, normally around 5psi. 5psi over the setpoint or 5 under, the pressure switch will turn off the system, and even if it don't turn it off, the compressor won't be able to complete a full stage change (gas to liquid) , thus no or low cooling.

I already saw systems that was loosing 1-2 psi / year, and this for years. No need to find and fix the leak.
No a bad idea tho, since eventually it will increase, and also environment.