2006 LEXUS IS 350

Typical onset: 80,000-150,000 mi

Symptoms: Rough idle, misfires, loss of power especially under load, Check engine light with multiple misfire codes (P0300-P0306), Severe cases: piston ring land failure, oil consumption 1+ qt/1000 mi, Catastrophic failure: broken ringlands, scored cylinder walls, metal in oil

Fix: Direct injection means no fuel washing intake valves—carbon chokes them shut. Walnut blasting valves every 60k-80k mi (4-6 hrs) prevents it. Once rings fail, you're looking at full engine rebuild or short block replacement (25-35 hrs labor). Many shops now do reman long blocks to avoid piecemeal work.

Estimated cost: $6,000-12,000

Typical onset: 100,000-140,000 mi

Symptoms: Transmission fluid leaking near radiator or under engine, Pink or red fluid puddles under car, Transmission overheating, harsh shifts if coolant contaminates ATF, In worst case: milkshake fluid (coolant mixed with ATF) requiring full trans flush

Fix: Factory cooler lines corrode at crimps or develop pinhole leaks. Replace both lines (not just the leaker) plus external cooler if present. If coolant got into trans, full flush and filter required. 3-5 hrs labor depending on crossmember removal needs.

Estimated cost: $800-1,800

Typical onset: 70,000-120,000 mi

Symptoms: Clunk or thud on acceleration or deceleration, Excessive engine movement visible under hood during throttle blips, Vibration through shifter or center console at idle, Driveline shudder during 1-2 or 2-3 upshifts

Fix: Rear transmission mount is hydraulic and fails internally—rubber separates or fluid leaks out. Jack trans, swap mount. Straightforward but annoying access. 2-3 hrs labor. OEM recommended; aftermarket mounts are hit-or-miss on NVH.

Estimated cost: $400-700

Typical onset: 90,000-130,000 mi

Symptoms: Clunking over bumps from front suspension, Steering wander or vague on-center feel, Inner or outer edge tire wear, Alignment won't hold specs after adjustment

Fix: Front lower control arm bushings (especially rear position) crack and tear. Lexus sells only complete arms—no press-in bushings available from OEM. Aftermarket bushings exist but require hydraulic press. Most techs replace whole arms. 3-4 hrs labor plus alignment.

Estimated cost: $800-1,400

Typical onset: 120,000-160,000 mi

Symptoms: Click or clunk but no crank when key turned, Intermittent no-start, especially when engine heat-soaked, Grinding noise during crank attempt, Eventually: no click at all, dead starter solenoid

Fix: Denso starters on these are good but not immortal. V6 mounting makes access tight—remove intake tube, work from top and below. Reman starters are fine. 2-3 hrs labor depending on tech agility.

Estimated cost: $500-900

Symptoms: Missing segments or lines in center LCD screen, Odometer or trip meter partially unreadable, Climate control display fading or blank sections, Progressive—gets worse with heat and age

Fix: LCD ribbon cable failures inside the instrument cluster. Remove cluster, send out for repair or replace cluster assembly. DIY solder fix possible for electronics-savvy owners. Dash removal 1.5-2 hrs, repair turnaround varies.

Estimated cost: $300-800