Describe the inspection of a diesel engine piston that has already been removed from the engine.(10)
Inspection of a Removed Diesel Engine Piston
A thorough inspection of a removed diesel engine piston is essential to assess its condition and determine the cause of any engine problems.
Visual Inspection
- Cracks and fractures: Check for any cracks, fractures, or other damage to the piston crown, skirt, or ring grooves.
- Wear patterns: Examine the piston crown for abnormal wear patterns, such as hot spots or scoring.
- Carbon build-up: Assess the amount of carbon build-up on the piston crown and in the ring grooves.
- Piston rings: Inspect the piston rings for wear, damage, and proper seating in the grooves.
- Oil control rings: Check the condition of oil control rings and scraper rings.
- Piston skirt wear: Examine the piston skirt for wear, scoring, or seizure marks.
Dimensional Checks
- Piston dimensions: Verify the piston’s dimensions against the original specifications to check for excessive wear or deformation.
- Piston ring clearances: Measure the clearances between the piston rings and the cylinder walls.
- Piston-to-cylinder clearance: Check the clearance between the piston and the cylinder liner.
Other Checks
- Material analysis: In some cases, it may be necessary to conduct material analysis to determine the cause of failure or degradation.
- Weight measurement: Compare the piston’s weight to the original specifications to check for excessive material loss.
By carefully inspecting the piston and its components, you can identify the root cause of engine problems and take corrective action.