Engine - Mis-Marked Timing Marks On Camshaft
Article No.98-25-14
12/21/98
ENGINE - TIMING ARROWS/FLAGS ON CAMSHAFT
SPROCKETS MIS-MARKED - 2.5L V6 DURATEC
ENGINES ONLY
FORD:
1996-98 CONTOUR, TAURUS
LINCOLN-MERCURY:
1996-98 MYSTIQUE, SABLE
1999 COUGAR
ISSUE
The timing arrows/flags on the back of the camshaft sprocket(s) are mis-marked by as much as 30 degrees rotation. The arrows or flags should not be used for engine service procedures, including timing diagnostics. The existing Service/Workshop Manual timing procedures are inaccurate.
ACTION
A timing check procedure has been developed, ignoring the arrows or flags on the rear side of the camshaft sprockets. Refer to the following Service Procedure for details.
SERVICE PROCEDURE
NOTE
THE 2.5L/3.0L DURATEC ENGINES ARE NOT "FREE-WHEELING." AN ERROR IN TIMING CHAIN INSTALLATION MAY RESULT IN SEVERE VALVE/PISTON DAMAGE. USE EXTREME CARE DURING TIMING CHAIN INSTALLATION.
REVISED CAMSHAFT TIMING DIAGNOSTIC CHECK
This procedure is in addition to the existing Service/Workshop Manual timing chain installation procedure. Any reference to the rear timing flags in the Service/Workshop Manual procedure should be ignored.
To check for proper camshaft timing without engine front cover removal, use the following procedure:
All checks are performed with the crankshaft at Top Dead Center (TDC) # 1, compression stroke.
1. Rotate the crankshaft clockwise until the notch on the crankshaft damper aligns with the TDO pointer on the engine front cover. This places the crankshaft at top dead center, cylinder number one. Rotate the crankshaft an additional full turn if the timing marks on the front of the camshafts are not above the top edge of the engine front cover. When the damper notch is aligned with the TDC pointer, and all of the camshaft front timing marks are above the top edge of the engine front cover, cylinder number one is on the compression stroke. Ignore the timing flags on the rear of the camshaft sprockets.
2. To check camshaft timing you must count the number of timing chain links between the camshaft front timing marks and the top edge of the engine front cover. Refer to Figure 1. Ignore the timing flags on the rear of the camshaft sprockets.
TIMING CHECK WITH FRONT COVER REMOVED
To check for proper camshaft timing during timing chain installation with the engine front cover removed, use the following procedure:
1. To place the crankshaft at TDC Cylinder # 1, compression stroke, rotate the crankshaft clockwise and place the crankshaft keyway at the 11 o'clock position. Rotate the crankshaft an additional full turn if the front camshaft timing marks are not on the top side of the camshaft sprockets.
2. To check camshaft timing you must count the number of timing chain links between the camshaft front timing marks, and the timing marks on the crankshaft sprockets. Refer to Figure 2. Ignore the timing flags on the rear of the camshaft sprockets.
OTHER APPLICABLE ARTICLES: NONE
WARRANTY STATUS: INFORMATION ONLY
OASIS CODES: 490000, 497000, 499000, 608000