Teardown reveals rare failure in Toyota's reliable 3.4-liter V-6 engine

Toyota's 3.4-liter V-6 engine, known for its reliability, has experienced a rare failure. A teardown by the I Do Cars YouTube channel revealed significant internal damage, including a disconnected piston and debris in the oil pan. The engine, a 5VZ-FE model, showed initial signs of good condition, with healthy camshafts and intact head gaskets. However, the discovery of a loose piston indicated a serious issue. The host suspects a stuck fuel injector caused a flooded cylinder, leading to the engine's failure. With replacement costs around $1,000, rebuilding this engine is unlikely.