Service Information

Volt

Symptoms - Engine Mechanical

Strategy Based Diagnostics

All diagnosis on a vehicle should follow a logical process. Strategy based diagnostics is a uniform approach for repairing all systems. The diagnostic flow may always be used in order to resolve a system condition. The diagnostic flow is the place to start when repairs are necessary.

Visual/Physical Inspection

•	Inspect for aftermarket devices which could affect the operation of the engine.

•	Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

•	Inspect for the correct oil level, proper oil viscosity, and correct filter application.

•	Verify the exact operating conditions under which the concern exists. Note factors such as engine RPM, ambient temperature, engine temperature, amount of engine warm-up time, and other specifics.

•	Compare the engine sounds, if applicable, to a known good engine and make sure you are not trying to correct a normal condition.

Intermittent

Test the vehicle under the same conditions that the customer reported in order to verify the system is operating properly.

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:

•	Base Engine Misfire without Internal Engine Noises

•	Base Engine Misfire with Abnormal Internal Lower Engine Noises

•	Base Engine Misfire with Abnormal Valve Train Noise

•	Base Engine Misfire with Coolant Consumption

•	Base Engine Misfire with Excessive Oil Consumption

•	Engine Noise on Start-Up, but Only Lasting a Few Seconds

•	Upper Engine Noise, Regardless of Engine Speed

•	Lower Engine Noise, Regardless of Engine Speed

•	Engine Noise Under Load

•	Engine Will Not Crank - Crankshaft Will Not Rotate

•	Engine Compression Test

•	Oil Consumption Diagnosis

•	Oil Pressure Diagnosis and Testing

•	Drive Belt Chirping, Squeal, and Whine Diagnosis

•	Drive Belt Rumbling and Vibration Diagnosis

•	Drive Belt Falls Off and Excessive Wear Diagnosis