1996 JIMMYS EQUIPPED WITH 4.3L ENGINES(RPO L35, VIN CODE 'W') MAY HAVE BEEN BUILT WITH THE THE CAMSHAFT SPROCKET ATTACHING BOLTS INADEQUATELY TIGHTENED. WHEN THE CAMSHAFT SPROCKET BOLTS ARE INADEQUATELY TIGHTENED, AN ENGINE FAILURE IS LIKELY TO OCCUR. TO CORRECT THIS CONDITION, DEALERS WILL REMOVE THE ENGINE FRONT COVER ASSEMBLY AND TIGHTEN THE CAMSHAFT SPROCKER BOLTS.