air filter BMW X5 1999 E53 Workshop Manual

Climate Control Systems (IHKR/IHKA)
Two climate control systems are offered on the X5, the manual IHKR system is standard
equipment on the 3 liter X5 and the IHKA system is available as an option. The IHKR is a
new system for US production and the IHKA is taken from the E39 vehicles.
Condenser/Receiver Dryer
The X5 incorporates a new design air conditioning condenser/receiver dryer for both the
manual (IHKR) and the automatic (IHKA) systems. The dryer cartridge and condenser are
one component with the dryer integrated on the left side. The dryer cartridge contains a
replaceable filter screen and dryer unit.
The condenser is partitioned which divides the condenser into cooling sections. The hot
refrigerant flows across the condenser and into the dryer through inlet holes at the lower
1/3 section of the cooling fins. After the refrigerant passes through the dryer it returns to
the evaporator through the outlet hole and bottom 1/3 section of the condenser.
Condenser Side View
Receiver Dryer
Filter
Screen
Bottom View
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Climate Control System (IHKR)
The manual system is controlled through the use of bowden cables for air distribution and
electronic control for temperature regulation and blower speed. One stepper motor is used
for the fresh/recirculated air intake.
The IHKR incorporates the following features:
• Fresh air intake grilles integrated into the hood - the fresh air passes through the single
micro filter installed in the center of front bulkhead.
The air then passes through the air duct, which is bolted to the bulkhead, and enters the
heater - A/C unit through the non-return flaps.
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Intake
Fresh Air

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IHKA Air Flow
The micro filter for the IHKA system is installed in the engine compartment in the center of
the fire wall.
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Warm Air Flow
Stratified Air Flow
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Air Supply System (LVA) Operation
The single stage piston compressor produces a maximum pressure of 13.5 Bar. The com-
pressor is maintenance free - provided it is used in a dust free environment. This includes
the compressor’s intake air filter.
The compressor is driven by a DC motor that is controlled by the compressor relay through
the control module.
When the compressor is activated, the pressure builds up to a working pressure of 11.4
Bar (+0.8/-1.5 Bar). This is controlled through the pressure maintenance valve. The air
under pressure is fed through the dryer and check valve to the solenoid valve block for the
air springs.
There is one solenoid valve in the valve block for each air strut. This allows the system to
compensate for uneven loads in the vehicle and maintain the vehicles ride height at all
times.
Pressure is drained through the left or right solenoid valve (energized open) the pressure
relief solenoid valve, restricter, check valve and dryer back to the inlet side of the compres-
sor pump.
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