Idle Air Control Thermal Valve - Acura 3.5 RL Manual

Idle Air Control Thermal Valve

Description
To prevent erratic running when the engine is warming
up, it is necessary to raise the idle speed. The idle air
control thermal valve is controlled by a thermowax
plunger. When the engine is cold, the engine coolant
surrounding the thermowax contracts the plunger,
allowing additional air to be bypassed into the intake
manifold so that the engine idles faster. When the
engine reaches operating temperature, the valve closes,
reducing the amount of air bypassing into the intake
manifold.
IDLE
ADJUSTING
SCREW
IDLE AIR
CONTROL
THERMAL
VALVE
IAC VALVE
AIR BYPASS
VALVE
WAX
Inspection
NOTE: The idle air control thermal valve is factory
adjusted; it should not be disassembled.
1. Remove the cover of the idle air control thermal
valve.
2. Start the engine.
3. Put your finger on the valve seat area, and make sure
that there is air flow with the engine cold (engine
coolant temperature below 86°F, 30°C) and idling.
IDLE AIR
CONTROL
THERMAL
VALVE
If there is no air flow, replace the idle air control
thermal valve and retest.
O-RINGS
Replace.
4. Start the engine. Hold the engine at 3,000 rpm with no
load (in Park or neutral) until the radiator fan comes
on, then let it idle.
5. Check that the valve is completely closed. If not, air
suction can be felt in the valve seat area.
If any suction is felt, the valve is leaking.
Check engine coolant level and for air in the engine
cooling system (see
If the cooling system is OK, replace the idle air control
thermal valve and recheck.
NOTE: If the cover of idle air control thermal valve was
removed, do the PCM reset procedure.
12 N-m
(1.2 kgf-m, 8.7 Ibf-ft)
section 10).