How to Recharge Air Conditioning BMW E90 328xi
How to recharge Air conditioning BMW E90 328xi: Low refrigerant is one of most common causes of inoperative air conditioning system in cars. Low refrigerant level happens when air conditioning system develops a leak and refrigerant escapes in atmosphere.
While is advisable to have a mechanic shop diagnose and repairs air conditioning system, recharging can also be done as a DIY at home. Its not as efficient as vacuuming and recharging professionally but in most cases is good enough, and much cheaper.
If recharging helps or not it will be decided by leak size (if you have a leak). If you have a small leak then you should be fine for a long while after recharging.
However, if you have a large leak on your air condition system then it will leak soon after and recharging wont help much.
Vehicle is 2011 BMW 3 series E90 328xi. Air conditioning recharging procedure is the same for all BMW 3 series models, E90, E91, E92 and E93 or BMW 323i, 328xi, 330i, 335i.
1) Safety First
You will be working close to a running hot engine and should be careful when recharging AC system.
- Wear gloves and safety glasses.
- Do not come in contact with refrigerant. Refrigerant is poisonous if inhaled, irritates skin and dangerous for your eyes.
- Do not wear lose clothes, you will be working close to spinning pulleys and belts.
- Engine will be hot, stay away from it.
- Keep away from engine pulleys and belts, watch where you put your hands.
- Use Low Pressure Port Only to recharge air conditioning. Do not try to fit connector on High Pressure Port.
- Read safety label on refrigerant bottle before you start working.
- Do not overcharge AC system.
2) Buy a Air Conditioning Recharging Kit
AC recharging kits cost about $50 and are sold almost everywhere, Walmart, Amazon, Canadian Tire and local automotive part stores. Buy a kit which comes with pressure gauge, you will need it to check pressure and not overcharge AC system.
2) Low Pressure Port and High Pressure Port BMW E90
You should use Only Low Pressure Port to recharge air conditioning. Do not try to fit connector on High Pressure Port. Low and high pressure ports are market with L and H on port protective caps.
High pressure port valve is larger than low pressure port and connectors designed for low pressure ports will not fit on high pressure port. There is a good reason for that. While pressure on low side varies between 40 to 50psi, pressure on high side is 5 times higher, 200 to 250psi. Bottle will explode if connected to high pressure. Make sure to identify Low Pressure Port prior to recharging.
3) Locate Recharging Port on Your BMW 3 Series
Low pressure air conditioning recharging port on BMW 328xi is located under the hood at bottom of windshield, drivers side. Its somewhat hidden, but is fairly easily accessible once you know where it is. Image below shows location marked with red arrow.
BMW E90 low pressure port is hidden behind power steering reservoir, red arrow.
4) Prepare Recharging Kit
Usually, recharge kits come with two refrigerant bottles in case one is not enough to fully recharge air conditioning system.
Open recharging kit valve fully, screw a bottle of refrigerant and tighten it firmly.
Close valve fully. Recharging kit valve has a pin which punctures refrigerant bottle and allow refrigerant to flow. Do not worry, wont leak as long as valve is closed.
5) Remove Low Pressure Port Protective Cap
Image below shows low pressure port with cap removed. It’s just a screw in plastic cap. Unscrew it and remove it.
Connecting recharging kit connector to low pressure port can be done in several ways. Here it was done without removing anything. Its a tight fit but it can be done, not that bad.
However, if you prefer more space, then unlip vacuum line clip and remove power steering reservoir. You dont have to remove power steering lines, just two 10mm bolts. It will allow you to move reservoir aside without any leaks (image below).
If you have small hands or don’t mind leaving some skin on your car then you can do it without removing reservoir or vacuum line.
(If you are also looking for fast and easy solution to sell your car, more here on “How To Sell Your Car Fast”. )
6) Connect Recharging Connector to BMW E90 Low Pressure Port
Recharging connector has an outer safety lock, same as air fittings on air tools. Pull locking ring back, push connector to recharging port and release lock.
Make sure recharging kit connector it connected securely to recharging port. If not, try again until connector is firmly in place (image below). Pull on it to confirm is locked properly.
7) Check Air Conditioning System Pressure
Look at the gauge and check pressure on system with engine off. If you still have some pressure left on AC system then leak is small and recharging will help.
If you have zero pressure on system then leak is large and there is a high probability will leak soon after recharging. However, since you there already, nothing to lose to try and recharge it.
8) Recharge Air Conditioning BMW E90 328xi
Start your car and put air conditioning on max setting with fan on full. Open recharging kit valve and shake refrigerant bottle. Air conditioning compressor should engage as soon as pressure hits 25psi.You should be able to hear compressor engage.
Keep recharging until pressure reaches 40psi when compressor is on. Pressure should be measured only when compressor is working. Do not look at pressure with compressor off, you will get false high reading.
9) Checking Air Conditioning System Pressure on BMW E90
Fully charged system is around 40 to 45psi with 45psi being the maximum. Do not let pressure go over 45psi. Stop periodically and check system [pressure to-make sure you do not overcharge air conditioning system. When you hear compressor engage look at pressure on gauge. If pressure is lower than 40psi, keep recharging.
If one refrigerant bottle is not enough:
- Turn engine off
- Remove recharging kit connector from low pressure port. Pull on locking ring to release it.
- Open valve fully and unscrew refrigerant bottle from recharging kit valve
- Screw a new bottle and tighten it
- Close recharging kit valve fully
- Reconnect connector on low pressure port, open valve and repeat recharging procedure
Keep looking at pressure, as soon as pressure hit 40psi with compressor working, stop recharging. 40psi indicates a fully charged system, anything over that can be considered overcharging.
10) Disconnect Recharging Hose
Close recharging kit valve and disconnected recharging hose connector from low pressure port. Turn engine off and listen for any hissing noises. Hissing noise indicates you have a large leak in the system and refrigerant is leaking.
In this case, when there is a large leak, you need professional diagnosis and repairs of air conditioning system in your car.
How to Recharge Air Conditioning BMW E90 328xi
11) Do not Over Charge BMW Air Conditioning System
More is not better when it comes to AC system pressure. If you overcharge it then system will not work. Air conditioning system has a pressure sensor which disconnects compressor if system pressure is too low or too high. This is done to protect compressor from damage that can be caused from too high or too low pressures. Higher than normal pressure can blow up internal compressor seals and destroy AC compressor.
System pressure need to be released back to normal levels in case of overarching. Low pressure port valve is very similar to valves in your tires.
However, releasing refrigerant into atmosphere is illegal in most jurisdiction and dangerous. System is under pressure and refrigerant will spray out with force if you press valve with screwdriver.
Do not try to release pressure with engine off. Refrigerant gas is poisonous if inhaled, will irritate skin and dangerous if it comes in contact with your eyes.
System should be vacuumed by a professional repair facility.
In case you just bought a used car: Maintenance After Buying a Used Car.
(If you are also looking for fast and easy solution to sell your car, more here on “How To Sell Your Car Fast” in Ontario).
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