Symptom Checks

Check the following items:

• Check cooling system for overheating. If cooling system is overheating, go to ENGINE RUNS HOT symptom.
• Check engine mechanical condition. Check compression, camshaft, valve train components, etc.

Check fuel delivery system. See CIRCUIT TEST HC in appropriate article:

For Contour & Mystique 2.0L, see TESTS W/CODES - 2.0L .

For Contour & Mystique 2.5L, see TESTS W/CODES - 2.5L .

For Windstar, see TESTS W/CODES .

• Check secondary ignition system. See CIRCUIT TEST JB in appropriate article:

For Contour & Mystique 2.0L, see TESTS W/CODES - 2.0L .

For Contour & Mystique 2.5L, see TESTS W/CODES - 2.5L .

For Windstar, see TESTS W/CODES .

• Check PCV system. See CIRCUIT TEST HB in appropriate article:

For Contour & Mystique 2.0L, see TESTS W/CODES - 2.0L .

For Contour & Mystique 2.5L, see TESTS W/CODES - 2.5L .

For Windstar, see TESTS W/CODES .

• On vehicles with OCT ADJ circuit (PCM terminal No. 30), check octane adjust input to PCM. See CIRCUIT TEST FG, step 5) in appropriate article:

For Contour & Mystique 2.0L, see TESTS W/CODES - 2.0L .

For Contour & Mystique 2.5L, see TESTS W/CODES - 2.5L .

For Windstar, see TESTS W/CODES .

• On vehicles with Knock Sensor (KS), check KS input to PCM. See CIRCUIT TEST DG in appropriate article:

For Contour & Mystique 2.0L, see TESTS W/CODES - 2.0L .

For Contour & Mystique 2.5L, see TESTS W/CODES - 2.5L .

For Windstar, see TESTS W/CODES .

• Check intake air system. Check engine oil quality. If available, check Technical Service Bulletins (TSBs) for octane adjust information. If no problems are indicated, return to SYMPTOM DIAGNOSIS  to identify any additional symptoms or go to CIRCUIT TEST Z in appropriate article and check for intermittent faults:

For Contour & Mystique 2.0L, see TESTS W/CODES - 2.0L .

For Contour & Mystique 2.5L, see TESTS W/CODES - 2.5L .

For Windstar, see TESTS W/CODES .