Engine - Spark Knock/Ticking Sound

Article No.
93-17-4

08/18/93

^ SPARK KNOCK OR INJECTOR "TICK"/VALVE TRAIN HASH TRANSFERRED FROM ENGINE TO PASSENGER COMPARTMENT - VEHICLES WITH 4.6L ENGINES BUILT BEFORE 4/1/93

^ RADIO - RADIO FREQUENCY CABLE TRANSFERS "TICKING" SOUND OR SPARK KNOCK FROM ENGINE TO PASSENGER COMPARTMENT - VEHICLES WITH 4.6L ENGINES BUILT BEFORE 4/1/93

^ NOISE - "TICKING" SOUND OR SPARK KNOCK - TRANSFERRED FROM ENGINE TO PASSENGER COMPARTMENT THROUGH RADIO FREQUENCY INTERFERENCE (RFI) CABLE - VEHICLES WITH 4.6L ENGINES BUILT BEFORE 4/1/93

FORD:
1992-93 CROWN VICTORIA

LINCOLN-MERCURY:
1991-93 TOWN CAR
1992-93 GRAND MARQUIS

ISSUE:
Normal engine sounds, injector "tick"/valve train hash, or spark knock may be transferred from the engine to the passenger compartment through the Radio Frequency Interference (RFI) cable. The RFI cable is located on the rear of the engine to the bulkhead side.

ACTION:
Remove the RFI cable. If the engine noise goes away, replace the RFI cable. Refer to the following procedure for service details.

1. Confirm the injector "tick"/valve train hash noise or spark by road testing the vehicle.

NOTE:
SPARK KNOCK IS USUALLY EXPERIENCED UNDER HEAVY LOAD WHEN THE VEHICLE IS DRIVEN AT SPEEDS OF 35 MPH (56 KM/H) OR HIGHER IN THIRD OR FOURTH GEAR, PRIOR TO DOWNSHIFTS DURING ACCELERATION.

2. Remove the RFI cable from the bulkhead mounting tab.

NOTE:
THE RFI CABLE IS A BRAIDED METAL CABLE ATTACHED TO THE RIGHT HAND SIDE CYLINDER HEAD AND A MOUNTING TAB ON THE RIGHT SIDE BULKHEAD.

3. Road test the vehicle, with the RFI cable removed, to determine if the engine noise is gone.

^ If the engine noise is gone, replace the RFI cable with a new revised RFI cable (F3AZ-19A095-A).

^ If the engine noise is still present, replace the RFI cable with a new revised RFI cable (F3AZ-19A095-A) and continue with Step 4.

4. If after the road test, the noise is still present, continue diagnosis to determine if the concern is spark knock.

5. If it is determined that the noise is spark knock, follow the procedures as outlined in TSB 92-9-3 and in the PCED Manual for spark knock diagnosis.

PART NUMBER PART NAME CLASS

F3AZ-19A095-A RFI Ground Strap Cable C

OTHER APPLICABLE ARTICLES: 92-9-3
WARRANTY STATUS:
Eligible Under Bumper To Bumper For 1991 Lincolns And All 1992/93 Models
OPERATION DESCRIPTION TIME
931704A Road Test, Remove Bad 0.9 Hr.
Cable, Install New Cable, Road Test

DEALER CODING
BASIC PART NO. CONDITION CODE
19AO95 08

OASIS CODES: 497000, 615000, 702000, 702300