Aircon
E30s are cool. But they won't keep you cool, and if you've got a tin-top in Diamond Metallic Black, then come those summer months you're really going to want something to lower the temperature in the cabin. That's where Aircon comes in.
Contents
Overview
Air-conditioning was fitted as an optional extra to E30s as early as 1984, and the system remained largely the same throughout the E30 production run. The system is based around a sealed refrigerant gas, just like your fridge at home. I won't explain the science, but as the refrigerant is converted from a gas to a liquid it gains heat; as it goes back to a gas it loses heat and cools, and it is this cooling effect we make use of. It's therefore essential that our system be completely sealed, to keep the refrigerant inside and doing what it should.
The system uses a number of components to compress, liquify, filter and evaporate the refrigerant. Valves regulate the flow of refrigerant through the pipework, and the whole system is controlled from a switch on the dashboard. A pressure switch monitors the condition of the coolant and determines whether or not the compressor needs to be engaged; if required, the clutch locks to drive the compressor.
Since its introduction, the original refrigerant has been made illegal for environmental reasons in the EU and many other states. A conversion kit to a more modern coolant is available from BMW.
Components
Compressor
Condensor
Receiver Drier
Evaporator
Expansion Valve
Pipework
Refrigerant
The original refrigerant gas for the aircon system was R-12; one of the more aggressive CFCs. It was banned in 1994.
However, since the E30 was still being produced in some markets in 1994, the final volume of aircon-equiped vehicles received a conversion kit to the less malevolent R-134a. Since the refrigerant in all E30s will be due for replacement (known as "recharging" the system), it is essential to convert your aircon over to an R-134a compatible system.
R-134a Kit
Radiator
Electric Fan
Aircon Clutch
Pressure Switch
Installation
Main article: Retrofitting Aircon.
Almost every car these days leaves the factory with air-conditioning, and this causes a shock to our soft, pampered bodies when we get into an E30. So to give yourself a (not-so) modern convenience, learn more about retrofitting Aircon.
Common Problems
Aircon systems use a controlled substance at their core. We do NOT recommend working on these systems yourself. In the event of any problems with your aircon system, consult a refrigeration specialist.
Aircon Won't Turn On
You press the switch, it lights up, but nothing happens. Most of the time, this is caused by a lack of refrigerant. If you haven't had the system serviced in a long time, it's not surprising for the cooling gas to have boiled or leaked away. If you don't replace the refrigerator drier then moisture in the system allows the pipes to corrode, leading to leaks. With all the refrigerant gone, there's nothing to provide any cooling effect, so you need to take the car to a professional.