Possible Cause & Correction
WARNING: This page does not describe the selected car, but rather 32 other vehicles, including the 2002 Saturn SL2, 2002 Saturn SL1, 2002 Saturn SL, 2002 Saturn SC2, and 2002 Saturn SC1. However, it is still accessible from the selected car via links, so may be relevant.
Check the following items:
- Check for incorrect valve timing, bent push rods, broken valve springs or worn camshaft lobes.
- Check for sticking or leaking valves.
- Check EGR valve for leaking base gasket or valve hanging open.
- Check for engine vacuum leaks and/or engine not tuned to specifications.
- Check ignition module ground and power feed circuits for poor or loose connections.
- Check air induction system for restrictions or air leaks. Also check for air leaks between Mass Airflow (MAF) sensor and throttle body. Check MAF sensor for proper operation.
- Check fuel injectors. Perform injector balance test. See FUEL INJECTOR BALANCE TEST under FUEL SYSTEMS in appropriate SYSTEM & COMPONENT TESTING article.
- Check fuel system. Perform BASIC FUEL SYSTEM CHECKS. See appropriate BASIC DIAGNOSTIC PROCEDURES article.
- Using Spark Tester (J-26792), check available output voltage of ignition coil.
- Check for crossfire between spark plugs and spark plug wires.
- Remove spark plugs and check for wet plugs, cracks, improper gap, burned electrodes or heavy carbon deposits. Also, check condition of spark plug wires. Spray spark plug wires with a fine mist of water to check for shorts.
- Check for proper Crankshaft Position (CKP) and Camshaft Position (CMP) sensor resistance.
- Check ignition system for faulty ground and power feed circuits.
- Check exhaust system for restrictions, such as a damaged or collapsed pipe, muffler or catalytic converter.
- Check intake and exhaust manifold passages for casting flash.
- Check harmonic balancer interrupter rings for missing, broken or bent vanes.
- Check for a low engine coolant level.
- Check the engine thermostat for the correct operation and heat range.
- Test the Torque Converter Clutch (TCC).
- Check the charging system. A bad diode in the alternator can allow A/C noise to enter the electrical system. This may affect the engine controls system operation.
- Check the transaxle range switch circuit and be sure the scan tool indicates the vehicle is in drive with the gear selector in Drive or in Overdrive.