2017 LEXUS RX 350

Typical onset: 40,000-90,000 mi

Symptoms: Oil level drops 1+ quart between changes without visible leaks, Blue smoke from exhaust on cold start or acceleration, Check engine light for misfire codes (P0300-P0306), Sudden loss of power or engine seizing in extreme cases

Fix: Root cause is defective piston rings allowing oil past into combustion chambers. Short-term: monitoring oil weekly, topping off between services (2-4 hrs). Long-term: complete engine rebuild with updated piston/ring design or short-block replacement (24-32 hrs labor). Toyota extended warranty coverage to 150k mi on some VINs under settlement, check eligibility first.

Estimated cost: $8,000-14,000

Typical onset: 60,000-100,000 mi

Symptoms: Rough idle, especially when cold, Hesitation or stumble on acceleration from stop, Reduced fuel economy (2-3 mpg drop), Misfires under load (codes P0300-P0306)

Fix: The 2GR-FKS uses both direct and port injection, but port injectors don't flow enough to prevent valve coking. Walnut blasting intake valves every 60-80k mi is preventive maintenance on this platform (6-8 hrs labor). Severe cases may need chemical soaking or manual scraping, adding time.

Estimated cost: $600-1,200

Typical onset: 70,000-120,000 mi

Symptoms: ATF puddle under engine bay, passenger side, Transmission temperature warning light, Burnt ATF smell after highway driving, Slipping or delayed shifts if fluid level drops significantly

Fix: The U760E/F 8-speed has external cooler lines with crimped fittings that corrode and weep. Replace both feed and return lines as a set (cooler itself rarely fails). 3-4 hrs labor including fluid refill and leak check. Must use WS ATF, don't cheap out with universal fluid.

Estimated cost: $500-900

Typical onset: 80,000-130,000 mi

Symptoms: Clunk or thud when shifting from Park to Drive/Reverse, Vibration at idle in Drive with brake applied, Visible engine movement when revving in Park, Increased cabin noise on acceleration

Fix: The rear transmission mount (between trans and subframe) fatigues from normal stress. Hydraulic fluid inside leaks out, rubber tears. Replace mount assembly (2-2.5 hrs). Often found during oil change inspections. Not urgent but worsens NVH.

Estimated cost: $350-600

Typical onset: 90,000-140,000 mi

Symptoms: Persistent misfire on specific cylinder after valve cleaning, Rough idle that doesn't improve with carbon service, Fuel trim values significantly negative on one bank, Check engine light with P0300 series codes

Fix: Even though this engine has dual injection, the port injectors still clog over time with low-quality fuel. Remove intake manifold, pull injectors, ultrasonic clean or replace (6-8 hrs for manifold R&R and injector service). Often discovered when carbon cleaning doesn't fully resolve driveability issues.

Estimated cost: $800-1,400

Typical onset: 60,000-110,000 mi

Symptoms: Gear oil drips on garage floor near rear axle, Whining or humming from rear on turns (if fluid low), Visible wetness around pinion seal or cover gasket

Fix: AWD models use a sealed rear diff that rarely sees service. Pinion seal hardens with age/heat cycles. Replace seal and refill with 75W-85 GL-5 (2-3 hrs). Check fluid level during regular service — most owners never do until it leaks.

Estimated cost: $300-550