Engine Defects Under Missouri Lemon Law

Engine defects routinely qualify under Missouri’s Lemon Law (§ 407.567). The combination of safety implications and substantial repair costs makes engine cases among the strongest.

Common engine failure modes

• Stalling — at speed, at idle, or on startup.
• Misfires — recurring CEL, rough idle, vibration.
• Excessive oil consumption — 1 qt per 1,000 miles or worse.
• Engine knock / detonation — pre-ignition or rod knock.
• Coolant loss — head gasket failure.
• Timing chain failure — premature stretch or skip.
• Turbocharger failure — recurring boost loss.

Brand-specific engine patterns

• Ford EcoBoost 3.5L / 2.7L / 2.3L (Claycomo F-150) — coolant intrusion, carbon buildup, turbo issues. MO home-state defendant.
• Ford 6.7L Power Stroke — CP4 fuel pump failure.
• GM 5.3L AFM (Silverado HD-adjacent) — lifter collapse, oil consumption.
• GM 6.6L Duramax LML / L5P — CP4 fuel pump failure.
• Hyundai / Kia Theta II — connecting-rod failure recall.
• Subaru EJ25 / FB25 / FB20 — head gasket, oil consumption.
• Audi / VW 2.0T TSI / TFSI — oil consumption, timing chain.
• Honda 1.5L Turbo — oil dilution.
• BMW N20 / N26 — timing chain.
• Nissan VR30DDTT — Infiniti Q50/Q60.

Why engine defects qualify

1. Safety — stalling in traffic is dangerous.
2. Substantial impairment — engine repairs are major.
3. Value impact — engine work flags vehicle history.

Missouri climate considerations

• Hot humid summers — cooling system stress.
• Cold winters with ice storms — cold-start issues, battery / ignition.
• Heavy I-70 / I-44 / I-29 highway use — sustained high-load running.
• Tornado / hail exposure — distinguish defect from hail damage.

Documentation specifics

• Oil consumption tests — manufacturer-run consumption tests.
• Compression tests — diagnostic data.
• Code numbers — engine DTCs.
• Tear-down photos — if engine teardown is performed.
• TSB references.

Bottom line

Engine defects qualify easily under Missouri’s Lemon Law. Ford EcoBoost coolant intrusion cases (Claycomo home-state) carry particular settlement leverage in W.D. Mo.

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