Engine - Intermittent Knocking Noise At Idle

91ford17

Article No.
91-9-8

05/01/91


^ ENGINE - 3.0L EFI - INTERMITTENT "KNOCKING" NOISE AT IDLE

^ NOISE - 3.0L EFI - INTERMITTENT "KNOCKING" AT IDLE


FORD: 1986-91 TAURUS 1990-91 PROBE

LINCOLN-MERCURY: 1986-91 SABLE

LIGHT TRUCK: 1986-91 AEROSTAR 1991 RANGER


This TSB article is being republished in its entirety to expand the vehicle application and model years.

ISSUE: An intermittent engine "knocking" noise at idle when the engine is warm may be caused by excessive camshaft end play. This "knocking" noise should not be mis-diagnosed as a rod or bearing knock. The camshaft "knocking" noise will go away when the idle speed is increased to about 1000 - 2000 RPM.

ACTION: Install a new thicker thrust plate to reduce the camshaft end play. Refer to the following service diagnostic procedure.


1. Remove front cover.

2. Measure camshaft end play to check if it is at or over the specification limits of 0.007 - 0.008 inch. If camshaft end play is at or slightly above specification, proceed to Step 3.


3. Remove timing chain and sprockets.

4. Replace thrust plate with 0.004 inch thicker service thrust plate (E8DZ-6269-B).

5. Reinstall timing chain, sprockets and front cover. Use a new front cover gasket (E6DZ-6020-A).

PART NUMBER PART NAME CLASS:

E8DZ-6269-B Thrust Plate B
E6DZ-6020-A Gasket - Front Cover BM

SUPERSEDES: 87-15-5
WARRANTY STATUS: Eligible Under Basic Warranty
Coverage, Powertrain
Warranty Coverage
OPERATION DESCRIPTION TIME
910908A Replace Thrust Plate 2.7 Hrs.
DEALER CODING
BASIC PART NO. CONDITION CODE
6250 56
OASIS CODES: 497000, 499000