2013 INFINITI M35H

Typical onset: 60,000-120,000 mi

Symptoms: Metallic knocking or ticking from engine especially when cold, Low oil pressure warning at idle, Sudden catastrophic engine failure with no warning, Metal shavings in oil during changes, Engine seizure in severe cases

Fix: The upper timing chain cover gasket allows oil starvation to rod bearings. Once knocking starts, it's often too late—bearings are scored. Requires complete engine teardown: inspect crank journals, replace all bearings, potentially grind crankshaft, replace gasket set, timing components. Many opt for used engine swap or short block replacement due to labor costs. Expect 25-35 hours labor for in-vehicle rebuild, 18-22 hours for R&R with reman engine.

Estimated cost: $6,500-12,000

Typical onset: 80,000-130,000 mi

Symptoms: Transmission fluid spots under vehicle near radiator area, Low transmission fluid warning, Slight burnt smell from engine bay, Slow engagement into gear when fluid level drops

Fix: The steel lines to the external cooler corrode where they pass through the subframe, especially in salt-belt states. Lines must be replaced as an assembly with new O-rings at the transmission case. Requires raising vehicle, removing splash shields, and careful line routing to avoid repeat failures. 2-3 hours labor plus parts.

Estimated cost: $450-750

Typical onset: 100,000-150,000 mi

Symptoms: Hybrid system warning light, Reduced electric-only range, Overheating warning for hybrid battery, Audible grinding or no sound from rear cabin cooling fan, Limp mode in hot weather

Fix: The lithium-ion battery pack has a dedicated cooling fan in the trunk area that pulls cabin air through the pack. Bearings fail or debris clogs the intake. Requires rear seat removal, access panel removal, and fan replacement. Fan is dealer-only part. 2-3 hours labor.

Estimated cost: $650-950

Typical onset: 70,000-110,000 mi

Symptoms: Clunking when shifting from Park to Drive or Reverse, Vibration during acceleration around 1500-2500 RPM, Excessive driveline movement felt through chassis, Visible sagging of transmission when inspected from below

Fix: The rear transmission mount (also supports the electric motor housing) uses a hydraulic design that fails internally. The mount tears or leaks fluid, allowing excessive powertrain movement. Replacement requires supporting the transmission, removing through-bolts, and installing OEM or quality aftermarket unit. 1.5-2 hours labor.

Estimated cost: $350-550

Typical onset: 90,000-140,000 mi

Symptoms: Hard starting after sitting overnight, Hesitation or stumbling during acceleration, Loss of power on highway, Check engine light with fuel pressure codes (P0087, P0088), Engine stalling at idle

Fix: The in-tank fuel pump and filter assembly can clog prematurely, especially with ethanol fuels. The pump itself may fail due to running dry when filter clogs. Requires dropping the fuel tank (subframe does NOT need to come out, but close clearances). Replace entire pump/sending unit assembly. 3-4 hours labor.

Estimated cost: $800-1,200

Symptoms: Check engine light with codes P0532, P0533, Poor fuel economy, Radiator always fully exposed, Clicking noise from front grille area on startup

Fix: The motorized grille shutters behind the front bumper fail mechanically or electrically. They're supposed to close at highway speed for aerodynamics and open for cooling. Stuck-open won't overheat the car but kills MPG. Requires front bumper removal and shutter motor/linkage replacement. 2 hours labor.

Estimated cost: $500-750