Recharging AC with R134

shadow191 · 05-26-2015, 12:44 PM

If you don't replace anything, probably not. Vacuuming the system won't remove the oil since it won't turn to vapor like water and exit the system. You'd only need to replace oil if you replaced parts. I added like 2 oz to mine after replacing the condenser since the drier is attached to it and each needs ~1oz. It's been 2 years and so far, the AC continues to work normally.

BRD1234 · 05-26-2015, 01:12 PM

Quote:

Originally Posted by shadow191

If you don't replace anything, probably not. Vacuuming the system won't remove the oil since it won't turn to vapor like water and exit the system. You'd only need to replace oil if you replaced parts. I added like 2 oz to mine after replacing the condenser since the drier is attached to it and each needs ~1oz. It's been 2 years and so far, the AC continues to work normally.

Thanks!
Not replacing anything, just completely refilling the system (evac and fill) just want to be sure I'm not forgetting anything.

Greatdane84 · 09-28-2015, 08:47 AM

Thanks for the post, everyone's comments helpful. Fingers crossed the psi holds. I was barely in the green (upper 20's) for psi and added enough to get up to midway blue which was around 35psi. Blowing cold for now.

HerrGruyere · 09-28-2015, 06:29 PM

I bought my E91 and I just thought the a/c in these cars was crappy. I bought a recharge kit from Autozone for like 30 bucks. Hooked it up and gave maybe 8 seconds total of charging in very long intervals. Car blows ice cold now. It really doesn't take much refrigerant so little is better.

drdre328xi · 08-07-2017, 08:15 PM

2008 car, 80k miles. Don't think the AC system has ever been touched.

After running engine for 10 mins AC full blast, LOW side measured 25 PSI, high side 115, 76 degree outside temp.

Added 134a from a 12oz can, let it sit for about 10 minutes. Can is maybe 2/3 empty now.

After running AC for a while on full blast, now have 34 PSI low end and the high end is way up at 205 PSI.

AC is working very well. Should I be worried by this major jump in high end pressure? any thoughts?

Thanks!!

shadow191 · 08-08-2017, 08:15 AM

High side should be something like twice ambient temperature + 50 degrees. So 205 psi sounds fine if it was 75-80 degrees when you did this. 30-35psi on the low side is good as well.

DYOOS · 08-23-2017, 01:40 AM

I'm looking to recharge my AC with 134a. I haven't done it before and I don't think the previous owners have. My AC isn't blowing as cold as I would like it to. Since this'll be my first time recharging with 134a, would a single 12oz can do the trick or does it need more/less?

Drifter2090 · 07-02-2018, 01:00 PM

Having the same issue with my AC, gonna try 134a today

bspeedracerb · 07-03-2018, 10:59 PM

Believe it or not I have a low mileage 330xi that just started blowing mediocrely cool air. I’ll report back after adding some straight 134a.

alexwhittemore · 07-13-2018, 12:54 PM

I strongly suggest you 3 read through the full thread - there are a lot of ways to screw this up, and while they PROBABLY won't destroy anything, you COULD mess up your pump and anyway, diagnosing is pretty difficult.

The PROPER way to charge the system is by mass, not pressure - you drain the system completely, pull a vacuum, and charge the proper amount by weight. That is, get a 18oz can if you can find it, or else measure the weight of the can as you fill (which is as tough as it sounds, gotta keep unscrewing it to weigh it, and hope you don't overshoot).

Anyway, it's not TERRIBLY hard with a proper manifold gauge and vacuum pump, which you can rent or borrow. But if you just use one of those stupid cans with a gauge on it, you're ASKING to screw it up. And if you overcharge, it won't blow cold, you'll think you've undercharged, and charging more could nuke your compressor.

EDIT erm, 2 of you. But to answer DYOOS's question a year late, NO. 12oz won't do it, unless you are, by some miracle of chance, exactly 12oz short (and if you are, there's a big leak you should get professionally sorted out).

DYOOS · 07-14-2018, 01:58 AM

Quote:

Originally Posted by alexwhittemore

I strongly suggest you 3 read through the full thread - there are a lot of ways to screw this up, and while they PROBABLY won't destroy anything, you COULD mess up your pump and anyway, diagnosing is pretty difficult.

The PROPER way to charge the system is by mass, not pressure - you drain the system completely, pull a vacuum, and charge the proper amount by weight. That is, get a 18oz can if you can find it, or else measure the weight of the can as you fill (which is as tough as it sounds, gotta keep unscrewing it to weigh it, and hope you don't overshoot).

Anyway, it's not TERRIBLY hard with a proper manifold gauge and vacuum pump, which you can rent or borrow. But if you just use one of those stupid cans with a gauge on it, you're ASKING to screw it up. And if you overcharge, it won't blow cold, you'll think you've undercharged, and charging more could nuke your compressor.

EDIT erm, 2 of you. But to answer DYOOS's question a year late, NO. 12oz won't do it, unless you are, by some miracle of chance, exactly 12oz short (and if you are, there's a big leak you should get professionally sorted out).

Appreciate the follow up Alex.

alexwhittemore · 07-14-2018, 12:39 PM

Quote:

Originally Posted by DYOOS

Appreciate the follow up Alex.

Hahaha, happy to "help" - what was your outcome in the end?

DYOOS · 07-15-2018, 05:22 PM

Quote:

Originally Posted by alexwhittemore

Hahaha, happy to "help" - what was your outcome in the end?

I've decided to get my AC re-charged professionally

alexwhittemore · 07-15-2018, 05:25 PM

Quote:

Originally Posted by DYOOS

I've decided to get my AC re-charged professionally

Hahaha, excellent choice.

Mark963 · 08-03-2018, 07:45 PM

I haven't been real happy with the AC in my 2011 E90. Using a wireless thermometer stuck into the dash vent, I was getting about 64F when it was around 90F outside. I have a Foxwell NT520 and it gave some interesting readings:

Footwell temp: 86
Evaporator temp: 57
Compartment temp: 82
Refridgerant pressure: 16.5 bar
Ventillation temp: 66
And a gauge on the low pressure end said 45 psi.

It is confusing as the pressures changes quite a bit as the engine rev's. That was after adding a little and then pulling the car out of the garage. When it was in the garage (maybe 95 degrees) it was getting up to 19 bar. I'm not really sure what the AC should be capable of in terms of temperature drop from the outside air source to what's coming out of the vents.

05-26-2015, 12:44 PM	#45
shadow191 Lieutenant Colonel 181 Rep 1,681 Posts Drives: 2017 Volvo XC90 R-Design Join Date: Dec 2012 Location: GA iTrader: (3)	If you don't replace anything, probably not. Vacuuming the system won't remove the oil since it won't turn to vapor like water and exit the system. You'd only need to replace oil if you replaced parts. I added like 2 oz to mine after replacing the condenser since the drier is attached to it and each needs ~1oz. It's been 2 years and so far, the AC continues to work normally.
	Appreciate 0 Quote

09-28-2015, 08:47 AM	#47
Greatdane84 Leeeroy Jankins 31 Rep 423 Posts Drives: 335i e90 LCI Join Date: Jan 2013 Location: SW Florida iTrader: (2) Garage List 2009 335i [10.00]	Thanks for the post, everyone's comments helpful. Fingers crossed the psi holds. I was barely in the green (upper 20's) for psi and added enough to get up to midway blue which was around 35psi. Blowing cold for now. Attached Images __________________ e90 LCI w/ -= VRSF 7" FMIC =- -= Cobb: Stg1 +FMIC Aggressive ST =- Last Install: BMS DCI + Caliper/Drum Paint "If you're not 1st, you're last" -Ricky Bobby
	Appreciate 0 Quote

09-28-2015, 06:29 PM	#48
HerrGruyere Private 10 Rep 84 Posts Drives: 2007 BMW 328xi Wagon Join Date: May 2015 Location: Baltimore, MD iTrader: (0)	I bought my E91 and I just thought the a/c in these cars was crappy. I bought a recharge kit from Autozone for like 30 bucks. Hooked it up and gave maybe 8 seconds total of charging in very long intervals. Car blows ice cold now. It really doesn't take much refrigerant so little is better.
	Appreciate 0 Quote

08-07-2017, 08:15 PM	#49
drdre328xi Registered 0 Rep 2 Posts Drives: Black E92 328xi 2008 Join Date: Oct 2013 Location: United States iTrader: (0)	I just added R134a to my system, here are my results. Welcoming feedback 2008 car, 80k miles. Don't think the AC system has ever been touched. After running engine for 10 mins AC full blast, LOW side measured 25 PSI, high side 115, 76 degree outside temp. Added 134a from a 12oz can, let it sit for about 10 minutes. Can is maybe 2/3 empty now. After running AC for a while on full blast, now have 34 PSI low end and the high end is way up at 205 PSI. AC is working very well. Should I be worried by this major jump in high end pressure? any thoughts? Thanks!!
	Appreciate 0 Quote

08-08-2017, 08:15 AM	#50
shadow191 Lieutenant Colonel 181 Rep 1,681 Posts Drives: 2017 Volvo XC90 R-Design Join Date: Dec 2012 Location: GA iTrader: (3)	High side should be something like twice ambient temperature + 50 degrees. So 205 psi sounds fine if it was 75-80 degrees when you did this. 30-35psi on the low side is good as well.
	Appreciate 0 Quote

08-23-2017, 01:40 AM	#51
DYOOS First Lieutenant 88 Rep 325 Posts Drives: 335i E90 N55 Join Date: Jul 2017 Location: Bay Area iTrader: (0)	I'm looking to recharge my AC with 134a. I haven't done it before and I don't think the previous owners have. My AC isn't blowing as cold as I would like it to. Since this'll be my first time recharging with 134a, would a single 12oz can do the trick or does it need more/less?
	Appreciate 0 Quote

07-02-2018, 01:00 PM	#52
Drifter2090 Colonel 908 Rep 2,091 Posts Drives: E90 M3 \| E92 335i \| E90 335d Join Date: Jul 2015 Location: Ontario, Canada iTrader: (1)	Having the same issue with my AC, gonna try 134a today __________________ MGM F82 M4 DCT / MPerformance / Swift / CSF / IND / Turner / BimmerWorld BSM F87 M2 6MT / Fabspeed / MPerformance / Turner / AutoID - SOLD JB-NB E92 M3 6MT / IND / RTD / Alpine / KW / ActiveAutowerke / 360Carbon - SOLD SS2-FR E90 M3 6MT / IND / AFE / ActiveAutowerke - SOLD AW-FR E90 M3 DCT / ACM / IND / AutoTecknic / K&N / H&R / Bilstein - SOLD
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07-03-2018, 10:59 PM	#53
bspeedracerb Private 7 Rep 53 Posts Drives: 2007 328xi Join Date: Aug 2013 Location: PA iTrader: (0)	Believe it or not I have a low mileage 330xi that just started blowing mediocrely cool air. I’ll report back after adding some straight 134a.
	Appreciate 0 Quote

07-13-2018, 12:54 PM	#54
alexwhittemore Lieutenant Colonel 110 Rep 1,951 Posts Drives: 2009 Crimson 328i Join Date: Oct 2012 Location: Los Angeles iTrader: (0)	I strongly suggest you 3 read through the full thread - there are a lot of ways to screw this up, and while they PROBABLY won't destroy anything, you COULD mess up your pump and anyway, diagnosing is pretty difficult. The PROPER way to charge the system is by mass, not pressure - you drain the system completely, pull a vacuum, and charge the proper amount by weight. That is, get a 18oz can if you can find it, or else measure the weight of the can as you fill (which is as tough as it sounds, gotta keep unscrewing it to weigh it, and hope you don't overshoot). Anyway, it's not TERRIBLY hard with a proper manifold gauge and vacuum pump, which you can rent or borrow. But if you just use one of those stupid cans with a gauge on it, you're ASKING to screw it up. And if you overcharge, it won't blow cold, you'll think you've undercharged, and charging more could nuke your compressor. EDIT erm, 2 of you. But to answer DYOOS's question a year late, NO. 12oz won't do it, unless you are, by some miracle of chance, exactly 12oz short (and if you are, there's a big leak you should get professionally sorted out). __________________
	Appreciate 1 DYOOS88.00 Quote

08-03-2018, 07:45 PM	#59
Mark963 Private 29 Rep 74 Posts Drives: 2011 328i Join Date: Jun 2018 Location: Iowa iTrader: (0) Garage List 2011 BMW 328 [0.00]	I haven't been real happy with the AC in my 2011 E90. Using a wireless thermometer stuck into the dash vent, I was getting about 64F when it was around 90F outside. I have a Foxwell NT520 and it gave some interesting readings: Footwell temp: 86 Evaporator temp: 57 Compartment temp: 82 Refridgerant pressure: 16.5 bar Ventillation temp: 66 And a gauge on the low pressure end said 45 psi. It is confusing as the pressures changes quite a bit as the engine rev's. That was after adding a little and then pulling the car out of the garage. When it was in the garage (maybe 95 degrees) it was getting up to 19 bar. I'm not really sure what the AC should be capable of in terms of temperature drop from the outside air source to what's coming out of the vents.
	Appreciate 0 Quote