Piston Seizure Quick Reference

Quick Reference Guide


Piston seizures will only occur when metal-to-metal contact between the piston, rings to liners exists. Thermal expansion and/or lack of lubrication are the primary causes for seizures. Piston seizures can be, but are not limited to, one or a combination of the following operational or serviceable conditions:


I. Causes for piston burning, crown erosions, crown overheating, crater cracking, thermal fracturing and nibbling:
1. Defective, contaminated, or incorrect injector
2. Incorrect or improperly calibrated injection pump
3. Early injection timing
4. Intake restriction
5. Exhaust restriction
6. Inoperative or incorrect turbo
7. Inoperative or misdirected oil spray jet
8. Lugging
9. Overloading
10. Incorrect rack settings
11. Inoperative and/or misadjusted governor
12. Use of ether

II. Causes of Four point scoring and either side of pin bore and piston skirt overheating:
1. Overheated cooling system
2. Low coolant level
3. Loss of coolant flow
4. Stuck thermostat
5. Water pump impeller spinning on shaft
6. Lack of crown cooling by the lube oil (spray jets)
7. Incomplete combustion (fuel washdown)
8. Defective or contaminated injector
9. Improper cold start and/or hot shutdown procedures
10. Inoperative radiator louvers if applicable
11. Defective pressure cap
12. Damaged or broken impeller
13. Air pocket at water pump
14. Plugged radiator
15. Plugged radiator cooling fins (bugs, paper etc.)
16. Coolant leaks
17. Inoperative or damaged piston cooling jet
18. Low oil pressure

III. Total piston scoring and/or seizure causes:
1. Progression from four point scoring (refer to list 2)
2. Counterbore or receiverbore distortions (out-of-round)
3. Pinched or rolled liner o-rings/crevice seal
4. Counterbore not concentric with block deck
5. Progression from ring scuffing
6. Use of silicone in o-ring/crevice seal groove area (form-a-gasket)
7. Grease or oil in o-ring/crevice seal groove prior to installation
8. O-ring contamination prior to installation (swelling)
9. Lube oil contamination (abrasives)
10. Air born contaminates (abrasives)
11. Bent or twisted connecting rod
12. Overloading
13. Lugging
14. Detonation
15. High air intake temperature and/or restriction
16. Exhaust restriction
17. Overfueling
18. Incorrect injection timing
19. Incorrect rack settings
20. Inoperative and/or incorrect turbo
21. Incorrect compression ratio
22. Air / Fuel ration imbalance
23. Incorrect fuel cetane rating
24. Incorrect oil classification

IV. Center skirt scuffing, elliptical cold/round when warmed causes:
1. High RPM before operating temperature
2. Engine load before operating temperature
3. Lack of skirt to liner clearance
4. Dry starts when prelube is required
5. Particle abrasive present

V. Causes for piston crown damage, foreign material or other:
1. Progression from ring scuffing
2. Progression from distortion seizure
3. Turbo compressor failure
4. Debris entering intake system
5. Installation debris
6. Valve failure - valve-impact
7. Incorrect installation of pin bushing, lack of retention might cause rod eye bushing to rotate
8. Malfunctioning and/or misadjusted jake brake
9. Incorrect jake brake usage
10. Extreme detonation
11. Excessive ether
12. Cold operation
13. Fast timing
14. Cyclic loading
15. Leaking injector 

Conclusion:
A thorough examination of the four major systems will aid in the investigation process. 
The four major systems are as follows:

► AIR INTAKE / EXHAUST SYSTEM
► FUEL SYSTEM
► COOLING SYSTEM
► LUBRICATING SYSTEM

The examination should also include operational hazards and repair practices.
  • Posted on   11/17/15 at 03:19:56 PM   by Sara  | 
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