Series 50 – Section 17.13 Low Compression

Section 17.13
Low Compression

To determine if low compression is causing starting difficulty, perform the following steps:‪

1. Perform a cylinder compression test; refer to "29.2 Cylinder Compression Test" .
2. Compare cylinder compression test results to specifications.
   1. If cylinder pressure is below specifications; refer to "17.13.1 Low Compression Repair" .
   2. If cylinder pressure is within specifications, call Detroit Diesel Technical Service Group.

Section 17.13.1
Low Compression Repair

Perform the following steps for low compression repair:‪

1. Remove cylinder head; refer to "1.2.2 Removal and Cleaning of Cylinder Head" .
2. Inspect the cylinder head for worn or damaged valves; refer to "1.2.3 Inspection of Cylinder Head" .
3. Replace damaged valves; refer to "1.4.2 Removal and Cleaning of Valve Spring (Cylinder Head Installed)" .
4. Inspect for worn or damaged cylinder kit components:
   1. Inspect cylinder liner for damage, refer to "1.20.1 Repair or Replacement of Cylinder Liner" .
   2. Inspect piston and piston rings for damage, refer to "1.18.1 Repair or Replacement of Piston and Connecting Rod" .
5. Verify repairs made to cylinder head valve(s) or cylinder kit components; refer to "17.13.1.1 Test Engine with Repaired Cylinder Head Valve(s), and Cylinder Kit" .

Section 17.13.1.1
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. Attempt to start and run the engine.
   1. If the engine starts and runs, no further troubleshooting is required. Shut the engine down.
   2. If the engine fails to start and run, call the Detroit Diesel Technical Service Group.