Interior - Booming Noise At Idle In Gear
88ford22Article No. 88-19-5
^ IDLE - "BOOMING" NOISE - 3.8L ENGINE
^ NOISE -IDLE "BOOM" - 3.8L ENGINE
LINCOLN-MERCURY: 1988 CONTINENTAL
CALIBRATIONS: 8-16D-RO5, 8-16D-R10
WARNING: This modification is authorized only for the listed calibrations. Performing this modification on other engine calibrations is unauthorized and could create liability under applicable federal or local laws.
ISSUE: A "booming" noise heard in the passenger compartment at engine idle with the transmission in gear may be caused by vehicle component stackup. Certain stackups in the vehicle make it sensitive to the engine idle speed.
ACTION: Use the following diagnostic procedure to determine if a new level EEC IV processor with a higher base idle speed is required.
1. Block the wheels and set the parking brake.
2. Disconnect the A/C compressor clutch wire at the A/C clutch.
3. Turn the A/C control switch to the "OFF" position.
4. Start the engine and allow it to reach normal operating temperature.
5. After normal operating temperature has been reached, position the gear selector to "D" drive.
WARNING: KEEP THE SERVICE BRAKE PEDAL APPLIED DURING THIS TEST.
6. Turn the A/C control switch to the "MAX A/C" position and set the blower control to the low position. This will increase the idle speed about 32 RPM.
NOTE: WHEN THE A/C CONTROL SWITCH IS IN THE "ON" POSITION, THE VEHICLE COOLING FAN WILL ALSO TURN "ON".
7. If the "boom" decreases to an acceptable level, install a new level EEC IV processor, (E80Y-12A650-AE).
NOTE: THE NEW PROCESSOR STRATEGY HAS A HIGHER BASE IDLE CONTROL SPEED.
8. If the "boom" does not decrease to an acceptable level, DO NOT install the new processor. Refer to the 1988 Continental Shop Manual, Section 18 for Noise/Vibration/ Harshness diagnosis.
9. Reconnect the A/C compressor clutch wire.
10. Remove the blocks from the wheels and disengage the parking brake.
AUTHORIZED MODIFICATION DECAL REQUIRED Obtain an Authorized Modification Decal and list the date, dealer number, and summary of alterations performed. Select a prominent place adjacent to the Vehicle Emission Control Information Decal suitable for installing the Authorized Modification Decal. Clean the area, install the decal and cover it with a clear plastic decal shield.
PART NUMBER PART NAME CLASS
E80Y-12A650-AE EEC IV Processor B
OTHER APPLICABLE ARTICLES: None
WARRANTY STATUS: Eligible Under Basic Warranty Coverage
OPERATION: 881905A - Replace EEC IV Processor
TIME: 0.8 Hr. Use "M" Time To Perform Step 8, If Required
DLR. CODING: Basic Part No. DRIVE
Condition Code: 56