Engine - Revised Camshaft Timing Procedure

Group Ref.: Engine

Bulletin No.: 476102

Date: March, 1994

SERVICE MANUAL UPDATE

SUBJECT:
SECTION 6A2 - ENGINE MECHANICAL - REVISED CAMSHAFT TIMING PROCEDURE

MODELS:
1993 CADILLAC ALLANTE, ELDORADO ETC AND SPORT COUPE, SEVILLE STS 1994 CADILLAC CONCOURS, ELDORADO ETC AND SPORT COUPE, SEVILLE STS AND SLS WITH 4.6L ENGINE (RPOS LD8 AND L37 - VIN CODES Y AND 9)

When servicing a 1993-94 Northstar V-8 engine cylinder head, and camshaft removal is required, please refer to the following information to ensure proper camshaft timing during reassembly. The service manual contains incorrect information concerning the installation sequence of the secondary camshaft drive chains.

If the secondary drive chains have been removed, you must install the left cylinder head secondary drive chain first and the right cylinder head secondary drive chain second. Service manual procedures 10 and 11 should reference the left intake and exhaust camshafts instead of the right, while step 15 should reference the right side camshafts instead of the left.

When camshaft removal is required, please note the following:

-References to the right and left cylinder heads are from the rear of the engine.

-The 4.6L Northstar is an interference engine, meaning that it is not free spinning and the pistons will strike the valves if the crankshaft is rotated with the camshaft drive disconnected or the camshafts are out of time.

-The camshaft tensioner levers are not interchangeable and are marked with left and right designations.

-The secondary chains, chain guides and chain tensioners are interchangeable.

-The left cylinder head secondary drive chain must be installed on the intermediate sprocket first.

Reference the section "Setting Camshaft Timing" in the appropriate service manual for complete camshaft timing procedure.