Important:
• | Cranking speed is critical for a diesel engine to start, whether the engine is hot or cold. Some tachometers are not accurate at cranking speed. The primary method of testing cranking speed or determining the accuracy of a tachometer is to use a scan tool. |
• | Ensure that the vehicle's batteries are in good condition, and fully charged, prior to performing this test. |
• | The minimum cold cranking speed required for the 6.5L diesel engine is 100 RPM. |
• | The minimum hot cranking speed required for the 6.5L diesel engine is 180 RPM. |
• | The actual cranking speed needed for starting will vary depending on the condition of the engine mechanical components (compression), and the condition of the fuel system components (fuel injection pump operating pressure, and fuel injection nozzles cracking pressure and spray pattern). |