Understanding Cylinder Scoring
Cylinder wall scoring is the disintegration of the cylinder liner surface (Alusil/Silitec). This allows oil to bypass the piston rings and burn in the combustion chamber. It is effectively a terminal engine diagnosis.
Symptoms
- Heavy oil consumption (1qt/500mi)
- Rhythmic 'thock-thock' knocking sound
- Misfire on specific cylinders
- Fouled spark plugs
At A Glance
- Repair Cost:
- $15,000+ (Engine Replacement)
- Prevention:
- Use high-quality fuel, change oil frequently, and replace leaking injectors immediately. Avoid short trips.
Affected Vehicles & Guides
The following detailed guides cover Cylinder Scoring specifically for the listed models.
Mercedes CLS550: Common Issues, Repair Costs & What to Know
The breakdown of Mercedes CLS550 (C218) reliability with M278 V8. Common failures: cylinder scoring, timing chain tensioners, electronics.
Mercedes E550 (M278 V8): Engine Problems & Reliability Guide
The breakdown of Mercedes E550 (W212) reliability with M278 V8. Common failures: cylinder scoring, timing chain tensioners, turbo coolant leaks.
Mercedes GL550 (M278 V8): Known Issues & Repair Priorities
The breakdown of Mercedes GL550 (X166) reliability with M278 V8. Common failures: cylinder scoring, timing chain tensioners, Airmatic suspension.
Mercedes S550 (M278 V8): Complete Reliability & Issue Guide
Is the Mercedes S550 (W222) with M278 V8 reliable? Brutally honest guide to owning the 449hp flagship. Cylinder scoring, timing chain, Airmatic.
