2016 LEXUS RX 350

Typical onset: 60,000-100,000 mi

Symptoms: rough idle especially when cold, hesitation on acceleration, misfires (P0300-P0306 codes), reduced fuel economy, extended cranking on cold starts

Fix: Walnut blasting the intake valves is the only real fix. Requires removing intake manifold and cleaning each cylinder through the intake ports. 4-6 hours labor depending on accessibility. Some shops use chemical cleaners first (rarely effective long-term). Severe cases show valve stem damage requiring head work.

Estimated cost: $600-1,200

Typical onset: 80,000-140,000 mi

Symptoms: transmission fluid spots under vehicle front-center, burnt ATF smell, transmission overheating warning, fluid level dropping without visible external leak at pan

Fix: The cooler lines corrode where they connect to the radiator-mounted cooler or at crimped fittings. Replacement requires dropping subframe or significant disassembly depending on which line fails. 3-5 hours labor. Critical to catch early—running low on ATF destroys the U760E transmission ($5K+ replacement). Always replace both lines together.

Estimated cost: $800-1,400

Typical onset: 90,000-130,000 mi

Symptoms: clunk when shifting from Park to Drive or Reverse, vibration at idle in Drive with brake applied, excessive engine movement visible when revving in Park, transmission tunnel vibration during acceleration

Fix: The hydraulic rear mount (supports transmission) fails internally and loses dampening. Requires lifting powertrain slightly to replace. 2-3 hours labor. Not safety-critical but annoying and can accelerate wear on exhaust hangers and CV boots if ignored.

Estimated cost: $400-700

Typical onset: 100,000-150,000 mi

Symptoms: whining or grinding noise from front of engine, coolant weeping from pump weep hole, engine overheating (late stage), squealing belt noise that changes with RPM

Fix: The 2GR-FE pump bearings fail before the impeller does. Requires serpentine belt removal and timing cover access on some sub-models. 2.5-4 hours labor depending on AWD vs FWD (AWD has tighter engine bay). Timing belt interference risk if pump seizes (though this engine is chain-driven, pump seizure can damage chain tensioner). Replace thermostat and hoses while in there.

Estimated cost: $600-1,000

Typical onset: 120,000-180,000 mi

Symptoms: intermittent no-crank (single click only), works after multiple key cycles, fails when engine is hot but works when cool, dash lights dim during failed crank attempt

Fix: Denso starters on these have internal contact disc wear. Starter is accessible from underneath (FWD) or requires removing intake components (AWD). 1.5-2.5 hours labor. Rebuild kits exist but most shops replace the unit. Fails without warning so keep jumper cables handy if you're seeing symptoms.

Estimated cost: $450-800

Typical onset: 80,000-120,000 mi

Symptoms: rough running that walnut blasting didn't fully cure, persistent misfire on one or two cylinders, poor fuel economy despite clean intake valves, lean codes (P0171/P0174) with no vacuum leaks

Fix: Direct injection system runs high pressure (2,000+ PSI) and poor fuel quality causes injector tip coking. Ultrasonic cleaning sometimes works; replacement is safest. Injectors are under the intake manifold. 3-4 hours labor to remove plenum and fuel rail. Replace all six if one fails—they age together. Must use Lexus or quality aftermarket; cheap injectors cause more problems.

Estimated cost: $1,200-2,000