Skip to main content


To determine if low compression pressure is causing rough running or stalling, perform the following steps: ‪

  1. Perform a cylinder compression test.
  2. Compare cylinder compression test results to specifications.
    1. If cylinder pressure is within specifications, call Detroit Diesel Technical Service.
    2. If cylinder pressure is below specifications, refer to section .

Low Compression Repair

Perform the following steps for low compression repair: ‪

  1. Perform low compression repair; refer to section .
  2. Verify repairs to cylinder head valve or cylinder kit components; refer to section .
Test Engine with Repaired Cylinder Head Valve(s) and Cylinder Kit

Perform the following steps to determine if the cylinder head valve and cylinder kit repair resolved starting difficulty: ‪

  1. Start and run the engine.
  2. Run the engine through its operating range with no-load for approximately 5 minutes, allowing the engine coolant to reach normal operating range, 88-96C (190-210F).
    1. If the engine is not running rough or stalling, no further troubleshooting is required. Shut down the engine.
    2. If the engine is running rough or stalling, shut down the engine. Call Detroit Diesel Technical Service.