2017 LEXUS IS 350

Typical onset: 60,000-100,000 mi

Symptoms: rough idle when cold, hesitation on acceleration, misfires under load, reduced fuel economy, check engine light with misfire codes P0300-P0306

Fix: Walnut blasting intake valves requires removing intake manifold and individually cleaning each valve—about 6-8 hours labor. Some shops use chemical induction cleaning as a band-aid but walnut blasting is the proper fix.

Estimated cost: $800-1,400

Typical onset: 80,000-150,000 mi

Symptoms: sudden onset of heavy knock/rattle, metal shavings in oil, complete loss of power, catastrophic noise from crankcase, sometimes preceded by slightly rough running

Fix: The direct-injection port sleeve can crack, allowing fuel to wash cylinder walls and starve bearings of oil—destroys pistons, bearings, and crank. Requires full engine rebuild or replacement. 25-35 hours labor for short block swap, more for complete rebuild. This is what's driving those head gasket, piston, bearing, and crankshaft jobs in your data.

Estimated cost: $8,000-15,000

Typical onset: 70,000-120,000 mi

Symptoms: shudder or vibration during light acceleration 25-45 mph, delayed or harsh 2-3 upshift, hesitation when downshifting for passing, occasionally harsh engagement from Park

Fix: Often starts with fluid and filter service (3 hours), but torque converter lockup clutch wear or valve body issues may require transmission rebuild or replacement (12-18 hours). Transmission oil cooler replacement sometimes needed if debris circulates.

Estimated cost: $400-800 for fluid service, $3,500-6,000 for rebuild

Typical onset: 80,000-130,000 mi

Symptoms: clunk when shifting from Park to Drive or Reverse, excessive vibration at idle in gear, visible tearing or separation of rubber mount, rattling over bumps

Fix: Rear transmission mount deteriorates from heat and stress. Replacement is straightforward—support transmission, unbolt old mount, install new. About 1.5-2 hours.

Estimated cost: $250-450

Typical onset: 100,000-150,000 mi

Symptoms: coolant leak from front of engine, whining or grinding noise from accessory belt area, overheating, visible coolant residue on pump housing

Fix: Bearing seals fail on the water pump. Timing cover must come off since pump is internal—about 6-8 hours labor. Do timing chain inspection and VVT components while you're in there.

Estimated cost: $1,200-2,000

Typical onset: 40,000+ mi

Symptoms: squeaking from dashboard over bumps, rattles from door panels, creaking from center console area, worse in cold or hot weather

Fix: Cheap interior plastics and poor clip retention—very un-Lexus-like. Requires disassembly, felt tape application, and clip replacement. Not a mechanical failure but annoying. 2-4 hours depending on severity.

Estimated cost: $200-500