2020 LEXUS IS 350

Typical onset: 60,000-90,000 mi

Symptoms: rough idle, hesitation on acceleration, misfires under load, reduced fuel economy

Fix: Walnut blasting the intake valves is the gold standard fix — requires intake manifold removal and 4-6 hours of labor. Catch cans help prevent recurrence but don't fix existing buildup.

Estimated cost: $600-1,200

Typical onset: 80,000-150,000 mi

Symptoms: sudden loss of power, rod knock, metallic rattling from engine bay, check engine light with misfire codes, oil consumption spikes before failure

Fix: The 2GR-FSE pistons have thin skirts that can crack, especially if the engine experiences detonation or runs hot. Once a piston cracks, debris circulates and destroys bearings. You're looking at either a full engine rebuild (pistons, rings, bearings, machining) at 25-35 hours labor, or a used/reman long block swap. Some owners catch it early with increased oil consumption.

Estimated cost: $6,000-10,000

Typical onset: 70,000-120,000 mi

Symptoms: transmission fluid pooling under vehicle, burnt transmission fluid smell, slipping shifts if fluid level drops significantly

Fix: The cooler lines running to the radiator develop leaks at crimp points or where they connect to the trans cooler itself. Replacement involves dropping the undertray and sometimes the radiator for access — 2-3 hours labor plus parts.

Estimated cost: $400-800

Typical onset: 80,000-120,000 mi

Symptoms: clunk when shifting into drive or reverse, excessive drivetrain vibration at idle, visible sagging or torn rubber on mount inspection

Fix: The rear transmission mount wears out from the V6's torque and the 8-speed's quick shifts. It's a 1.5-2 hour job — trans needs slight support to swap the mount, but straightforward.

Estimated cost: $250-450

Typical onset: 90,000-130,000 mi

Symptoms: misfires on specific cylinders, rough running that doesn't clear with valve cleaning, lean fuel trims on one bank

Fix: Direct injectors on the 2GR-FSE can clog or fail, often discovered after valve cleaning doesn't solve a misfire. Injectors are under the intake manifold — you're already in there if doing carbon service. Replacement is 1-2 hours if manifold is already off, 4-5 hours from scratch. Use OEM or quality aftermarket only.

Estimated cost: $800-1,400

Typical onset: 60,000-100,000 mi

Symptoms: rattling noise for 1-2 seconds on cold start, check engine light with VVT advance/retard codes (rare), noise disappears once oil pressure builds

Fix: The cam phaser actuators can develop slop or the oil control valve screens get clogged with sludge. If it's just cold-start rattle and goes away, it's livable. If you get codes, replacing the actuators requires valve cover removal — 3-4 hours per bank.

Estimated cost: $600-1,200