1992-94 CHEVROLET LUMINA APV 1992-94 OLDSMOBILE SILHOUETTE 1992-94 PONTIAC TRANS SPORT WITH 3800 ENGINE (VIN L - RPO L27)
PISTON PIN TICK OR RATTLE MAY BE DESCRIBED BY CUSTOMERS AS A TICKING NOISE THAT BEGINS SHORTLY AFTER COLD START-UP AND GRADUALLY DIMINISHES AS THE ENGINE WARMS UP. IN MOST CASES, THE NOISE IS GONE AFTER FIVE MINUTES. IN SEVERE CASES, THE NOISE MAY NOT DISAPPEAR WHEN THE ENGINE IS HOT.
PISTON PIN NOISE OCCURS IN BOTH PARK AND DRIVE AT IDLE RPM, VARYING IN INTENSITY DEPENDING ON THE NUMBER OF PISTONS INVOLVED. A TICKING SOUND MEANS ONE PISTON IS AFFECTED; A MARBLY RATTLE OR DIESEL-TYPE SOUND MEANS TWO OR MORE PISTONS ARE AFFECTED.
THE SPECIFICATION FOR PISTON-TO-PIN CLEARANCE IS 0.0004 TO 0.0008 INCH (0.010 TO 0.020MM). STUDIES HAVE SHOWN THAT TRACE LEVELS OF NOISE CAN OCCUR BETWEEN 0.0006 AND 0.0008 INCH (0.015 TO 0.020MM). WHEN THE CLEARANCE IS AT 0.0008 (0.020MM), THE NOISE MAY BECOME AUDIBLE TO THE CUSTOMER.
**NOTE** TESTS HAVE ALSO SHOWN THAT PISTON PIN RATTLE DOES NOT HAVE ANY NEGATIVE EFFECTS ON SHORT TERM OR LONG TERM ENGINE DURABILITY.
IF PISTON PIN NOISE IS DETECTED AND THE CUSTOMER DESIRES THE CONDITION TO BE CORRECTED, REPLACE ALL SIX PISTONS AND PINS. THE NEW PISTON SETS HAVE MINIMAL PISTON-TO-PIN CLEARANCES.
USE THE PROCEDURE OUTLINED IN THE APPROPRIATE SERVICE MANUAL FOR PISTON REPLACEMENT.
**NOTE** WHEN INSTALLING THE NEW PISTON AND PIN ASSEMBLY ONTO THE EXISTING RODS, USE EXTREME CARE TO AVOID DAMAGE TO EITHER THE PIN OR PISTON PIN BORE. IF DAMAGE TO THESE AREAS OCCUR, THE NOISE WILL RETURN BECAUSE THE DAMAGE WILL CAUSE WEAR AND EXCESSIVE CLEARANCE.
PARTS INFORMATION: PISTON ASSEMBLY APPLICATION PART NUMBER ----------- --------------- 1990-92, INCLUDING 1993 BUICK RIVIERA 12537198 1993-94 12537200
PARTS ARE CURRENTLY AVAILABLE FROM GMSPO.
LABOR OPERATION: J1307 USE PUBLISHED LABOR OPERATION TIMES.
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