2012 INFINITI M35H

Typical onset: 60,000-100,000 mi

Symptoms: transmission fluid leaking from cooler lines, overheating transmission warnings, limp mode activation, pink or milky fluid indicating coolant cross-contamination

Fix: Replace oil cooler and all associated lines, flush both transmission and cooling system if cross-contaminated. 4-6 hours labor depending on contamination severity. Often triggers need for full transmission fluid replacement with Nissan NS-3 fluid only.

Estimated cost: $1,200-2,200

Typical onset: 80,000-130,000 mi

Symptoms: sudden loss of oil pressure, violent knocking from lower end, metal shavings in oil, engine seizing without warning, no prior oil consumption or external leaks

Fix: This is the VQ35 gallery gasket defect where internal gasket failure starves cylinders 5-6 of oil. By the time symptoms appear, crank and rod bearings are destroyed. Requires complete engine rebuild with updated gallery gaskets, new bearings, honing, and often new pistons/rings. 25-35 hours labor. Many shops recommend used engine replacement instead due to core damage severity.

Estimated cost: $6,500-12,000

Typical onset: 90,000-140,000 mi

Symptoms: master warning light with hybrid system error, loss of electric assist, vehicle runs gas-only with reduced power, clicking from under rear seat area, won't start or starts only on gas engine

Fix: The inverter and intelligent power distribution module under the rear seat fail due to heat cycling. Diagnosis requires Consult III scan tool. Inverter replacement is 6-8 hours, module is 3-4 hours. Parts are dealer-only and expensive. Some failures covered under extended hybrid warranty to 10yr/150k in certain states.

Estimated cost: $3,500-7,000

Typical onset: 70,000-110,000 mi

Symptoms: clunking when shifting from Park to Drive, excessive vibration at idle, transmission appears to shift hard, visible sagging of transmission when inspected on lift

Fix: The front transmission mount supporting the hybrid transaxle fails due to extra weight of electric motor. Often misdiagnosed as transmission problem. Replace mount with OEM or upgraded polyurethane unit. 2-3 hours labor with proper support equipment.

Estimated cost: $400-700

Typical onset: 100,000-150,000 mi

Symptoms: rough idle and hesitation, long crank before starting, loss of power under acceleration, fuel pressure codes P0087 or P0088, metallic whine from engine bay

Fix: Direct injection system uses in-tank filter that clogs and starves high-pressure pump. Filter is not serviceable separately—requires fuel pump module replacement. High-pressure pump driven off exhaust cam also fails. Filter/pump replacement 3-4 hours, high-pressure pump 5-6 hours due to intake manifold removal.

Estimated cost: $1,200-2,400

Typical onset: 80,000-120,000 mi

Symptoms: hybrid battery overheating warnings, reduced electric assist in hot weather, loud rattling from behind rear seat, hybrid system shuts down until cooled

Fix: Dedicated cooling fan for lithium-ion battery pack fails—bearings seize or control module quits. Fan assembly is behind rear seat with battery pack. 2-3 hours labor to access and replace. Must use OEM part as aftermarket units don't meet cooling specs.

Estimated cost: $800-1,400