Kia Optima: RCV Control Solenoid Valve. Description and OperationWhen the throttle is closed, while the engine is running at cruise rpm (tip-out), the turbocharger boost pressure raises rapidly. The pressure wave strikes a compressor blades causing a knocking noise. To prevent this the ECM opens the recirculation valve which allows excessive boost pressure to vent back to the air cleaner side of the turbocharger compressor.

Adjustment
RCV Control Solenoid Valve. SpecificationsKnock Sensor (KS). Schematic Diagrams
Circuit Diagram
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Replacement
Standard values, such as torques and certain adjustments, must be strictly
observed in the reassembly of all parts.If removed, the following
parts should always be replaced with new ones.
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Removal
Front Speaker
1.
Remove the front door trim panel
and speaker connector.(Refer to the BD group - "Front door")
2.
Remove the front speaker (A)
after loos ...