KNOCKING NOISE AT IDLE WARM REPLACE INTAKE CAM HSG. ASSY.

Subject: KNOCKING NOISE AT IDLE WITH ENGINE WARM (REPLACE INTAKE CAMSHAFT HOUSING ASSEMBLY)

Models Affected: 1992 GRAND AM MODELS WITH 2.3L ENGINE (VIN D)

TRANSAXLE MODELS: Automatic Transaxle Only

CONDITION:

Intake camshaft makes knocking noise during idle at normal operating temperatures.

CAUSE:

Intake camshaft knocks due to end play.

CORRECTION:

Verify that the camshaft is making the knocking noise by the following procedure.

1. Turn A/C control off.

2. Start engine and bring to a fully warmed up idle (700 rpm).

3. Use the beveled end of a wooden dowel (1/2" dia. x 8" to 12" long with one end beveled) to apply moderate axial pressure (approximately 10 pounds of force) on the intake camshaft at the center of the P/S drive pulley (refer to illustration).

CAUTION:

To avoid personal injury care should be taken to place a dowel directly at the center of the camshaft; otherwise, the risk of losing control of the dowel exists.

4. If the knocking noise is eliminated, the noise is due to camshaft end play.

5. Replace the intake camshaft housing assembly with service part #24573362, which will reduce end play.

NOTE: It is not necessary to replace the camshaft.

SERVICE INFORMATION:

Refer to Section 6A7 for intake camshaft housing replacement procedure.

PARTS INFORMATION:

PART NUMBERS PART DESCRIPTIONS ------------ ----------------- 24573362 Housing Assembly Intake Camshaft w/Cover 12334625 Gasket Kit, Camshaft Carrier Intake

Parts are expected to be available on April 27, 1992. In case of limited inventory, parts will be placed on 400 control to waive VIP surcharges. only verifiable emergency VIP orders will be accepted. SPO will make every effort to obtain parts. However, the part will be shipped premium transportation at dealer's expense and all other order types will be placed on backorder until the 400 control is removed.

WARRANTY INFORMATION:

Labor Time Operation Number: T1852 Labor Time Allowance: 5.5 hrs.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.