WHY DOES CAR RUN ROUGH ONLY WHEN WARMED UP??
Asked by GuruDTHG22 Jul 02, 2024 at 11:11 AM about the 2005 Chevrolet Cobalt LS Coupe FWD
Question type: Maintenance & Repair
THE CAR RUNS FINE WHEN COLD, BUT STARTS TO BUCK, AND BOG
DOWN AFTERN IT HAS WARMED UP. ORIGINALLY THREW CAM POSITION
SENSOR CODE. REPLACED IGNITION COIL/MODULE, SPARK PLUGS,
VALVE COVER GASKET, FUEL LINE AND FUEL FILTER..CLEANED MAF
SENSOR AND AIR FILTER. PROBLEM STILL EXISTS...WHATS WRONG??
3 Answers
You need a live data scan. Could be a sensor misread or a computer error when it gets to operational temperature. This old of a vehicle stay away from the dealer, find a good independent shop in your area and have them check it over
beatupchevy answered 4 months ago
did you test the plug wires ? Spray some carb cleaner down the throttle if you can
Could be a leaking gasket. When things warm up they expand and something could be opening up. The intake manifold or throttle body gasket would be my first suspects. A skewed coolant temperature sensor can also cause the engine to run poorly by sending the wrong information to the computer. Jim