         
"Hard, Slow or No Start" During Crank on Some GM Vehicles Affected Models 1999-2000 Cadillac Escalade 1995-2000 Chevrolet and GMC SIT models 1996-2000 Chevrolet, GMC C/K, M/L, G, P models, and Oldsmobile Bravada. With 4.3L, 5.0L, 5.7L or 7.4L engine (VINS w, x, M, R, J: RPOS L35, LF6, L30, L31, L29) Some customers may comment on one or more of the following conditions: · Backfire or kickback during crank / start · No start or slow or hard start/ crank · Grinding or unusual noises during crank/start · cracked or broken engine block at the starter boss · Broken starter drive housing · Broken starter ring gear on flywheel or · Any combination of the above. A condition may exist that allows the crankshaft position sensor to command up to 50 extra degrees of spark advance during engine cranking only. This in turn exposes the engine to higher-than-normal cylinder pressures, which may result in an inoperative condition to the starter drive housing, the engine flywheel starter ring gear or the engine block at the outside edge of the starter boss. To correct this, first inspect for a stored powertrain DTC P0338. This DTC will not illuminate the "Service Engine Soon" light. If this code is stored, the crankshaft position sensor, P/N 10456607, must be replaced and the remaining components must be inspected for damage (engine block at the starter boss, the starter drive housing and the engine flywheel starter ring gear). Notice: When DTC P0338 is set, failure to replace the crankshaft position sensor could result in repeated inoperative conditions of the starter or flywheel. Important: Some flywheel wear is normal; broken or missing teeth and/or cracks are not. Source: Courtesy of ALLDATA UNDERHOOD Service Magazine (May 2003 Issue) 
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