Additional Symptoms Tests

Hard Start

• Verify the ECT has not shifted in value. Refer to Temperature Versus Resistance - Engine Coolant Temperature Sensor .
• Inspect for a slow cranking speed. Refer to Symptoms - Engine Electrical .
• Verify the engine electrical system for correct operation. Refer to Symptoms - Engine Electrical .
• Verify the driver is using the correct starting procedure as described in the owner's manual.
• Inspect for a restriction in turbocharger inlet duct.
• Inspect for a restriction or a leak in the intake manifold.
• Inspect the exhaust system for a possible restriction. Refer to Restricted Exhaust .
• Inspect for more than the customer would desire crankshaft end play that will cause the crankshaft position sensor reluctor wheel to move out of alignment with the crankshaft position sensor.

Hesitation, Sag, Stumble

• Test the generator. Refer to Symptoms - Engine Electrical .
• Inspect for more than the customer would desire crankshaft end play that will cause the crankshaft position sensor reluctor wheel to move out of alignment with the crankshaft position sensor.

Poor Fuel Economy

• Heavy loads being carried or towed
• Acceleration rate too much or too often
• Inspect the brake system for brake drag.
• Inspect the tires for the correct air pressure.
• Inspect for incorrect operation of the speedometer.
• Inspect for an air leak in the charge air cooler.
• Inspect the air conditioning system for proper operation.
• Suggest to the owner to fill the fuel tank and inspect the fuel economy.
• Suggest to the driver to read the Important Facts on Fuel Economy in the Owner's Manual.
• Verify the ECT has not shifted in value. Refer to Temperature Versus Resistance - Engine Coolant Temperature Sensor .

Lack of Power, Hesitation, or Cut Out

• Inspect the engine electrical system for correct operation. Refer to Symptoms - Engine Electrical .
• Compare the vehicle with a similar model. Ensure the vehicle has an actual condition.
• Inspect for a proper transmission operation.
• Inspect the engine oil level and quality.
• Inspect for an air leak in the charge air cooler.
• Inspect for a worn or damaged turbo charger turbine wheel, shaft or compressor wheel.
• Inspect for a restricted or plugged exhaust. Refer to Restricted Exhaust .
• Inspect for a restriction in the charge air cooler.
• Inspect for a skewed mass air flow (MAF) sensor.
• Inspect that the exhaust gas recirculation (EGR) valve is fully closing.
• Ensure that the EGR valve does not bind when manually moving the valve.
• Inspect the torque converter clutch (TCC) operation.
• Inspect the air conditioning system for the correct operation.

Rough, Unstable, or Incorrect Idle and Stalling

• Inspect the engine mounts.
• Inspect the intake and exhaust manifolds for casting flash.
• The exhaust system for damaged or collapsed pipes
• The exhaust manifold for a collapsed inner wall
• The mufflers for heat distress or possible internal failure
• Inspect the park neutral position switch circuit.

Surges/Chuggles

• Ensure the driver understands the torque converter clutch (TCC) operation.
• Ensure the driver understands the A/C compressor operation.
• Use the scan tool to ensure the vehicle speed sensor (VSS) reading matches the speedometer.

Fuel Knock/Combustion Noise

• Inspect for obvious overheating problems.
• Inspect for a low engine coolant level.
• Inspect for any restricted air flow through the radiator.
• Inspect for a malfunctioning or incorrect thermostat.
• Inspect for a correct coolant solution. The solution should be a 50/50 mix of anti-freeze and water.
• Perform the Small Quantity Learn.