Engine Families by Complaint Volume
Documented problem engine families ranked by NHTSA owner complaints, with complaints normalized per model-year entry so families of different production volumes can be compared.
The Hyundai/Kia Theta II 2.4L leads with 30,181 NHTSA complaints — about 718.6 per model-year entry across 42 of them.
| engine family | manufacturer | displacement | complaints | complaints per modelyear | source |
|---|---|---|---|---|---|
| Hyundai/Kia Theta II 2.4L | Hyundai/Kia | 2.4L | 30,181 | 718.6 | view › |
| GM 3.6L LFX/LLT V6 | General Motors | 3.6L | 24,541 | 303 | view › |
| Ford 3.5L EcoBoost (1st gen) | Ford | 3.5L | 22,886 | 572.2 | view › |
| Ford 5.4L Triton V8 | Ford | 5.4L | 20,792 | 346.5 | view › |
| Toyota 2GR-FE V6 | Toyota | 3.5L | 19,096 | 335 | view › |
| Hyundai/Kia Theta II 2.0L Turbo | Hyundai/Kia | 2.0L | 18,120 | 503.3 | view › |
| Honda J35 V6 with VCM | Honda | 3.5L | 15,257 | 317.9 | view › |
| Ford 1.6L EcoBoost | Ford | 1.6L | 14,512 | 806.2 | view › |
| Honda 1.5L Turbo (L15B7) - Oil Dilution | Honda | 1.5L | 12,199 | 717.6 | view › |
| Chrysler 2.7L V6 | Chrysler | 2.7L | 10,821 | 416.2 | view › |
| VW/Audi 2.0T (EA888) | Volkswagen/Audi | 2.0L | 10,680 | 130.2 | view › |
| Ford 4.6L 2-valve Modular V8 | Ford | 4.6L | 9,444 | 185.2 | view › |
| Mercedes M272 V6 / M273 V8 | Mercedes-Benz | 3.0L-5.5L | 8,695 | 142.5 | view › |
| GM 5.3L V8 with AFM | General Motors | 5.3L | 7,694 | 213.7 | view › |
| GM 2.4L Ecotec (LAF/LEA/LUK) | General Motors | 2.4L | 7,609 | 345.9 | view › |
| GM 1.4L Turbo (LUV/LUJ) | General Motors | 1.4L | 6,999 | 152.2 | view › |
| Subaru EJ25 (head gasket era) | Subaru | 2.5L | 3,896 | 144.3 | view › |
| Ford 4.0L SOHC V6 (Cologne) | Ford | 4.0L | 3,586 | 155.9 | view › |
| Subaru FB (oil-consumption era) | Subaru | 2.0L / 2.5L | 1,954 | 177.6 | view › |
| BMW N20 / N26 4-cyl Turbo | BMW | 2.0L | 1,402 | 40.1 | view › |
| Ford 6.0L Powerstroke Diesel | Ford | 6.0L | 1,108 | 44.3 | view › |
Showing the top 21 of 21 engine families. The full dataset is free to download and republish with attribution:
Methodology
Families are the editorial set powering /engines/. For each family we sum complaints/recalls/harm flags across every matching (year, make, model) in the DB. "complaints_per_modelyear" = total complaints ÷ model-year entries present. Complaints are unverified consumer reports.
Source: US NHTSA owner complaints + recalls (public record), MY 2005–2025. License: CC BY 4.0 —
cite as ProblemsByVin (https://problemsbyvin.com). Computed from the database snapshot dated 2026-08-30.
Reporters: we'll pull a custom cut of this — by make, model year, state, or component — and our reliability analyst can speak to methodology on the record. Get in touch ›