2018 INFINITI Q70

Typical onset: 60,000-100,000 mi

Symptoms: Transmission fluid mixing with coolant (strawberry milkshake in coolant reservoir), Harsh shifting or slipping between gears, Check engine light with transmission temp codes, Overheating transmission leading to catastrophic failure if ignored

Fix: Replace transmission oil cooler, flush entire cooling system AND transmission with multiple fluid exchanges. If contamination went unnoticed, transmission rebuild is often required. Cooler replacement alone: 4-5 hours labor. With transmission rebuild: 12-18 hours.

Estimated cost: $1,200-1,800 (cooler only), $4,500-7,000 (if transmission damaged)

Typical onset: 80,000-120,000 mi

Symptoms: Reduced fuel economy (MPG drops significantly), Master warning light with hybrid system fault codes, Limited EV mode range or inability to enter EV mode, Battery capacity bars depleting on dash display

Fix: Lithium-ion hybrid battery replacement requires specialized tools and safety training. Dealership-only repair in most cases. 6-8 hours labor. Some independent hybrid shops offer module-level rebuilds at lower cost.

Estimated cost: $5,000-8,500 (new OEM), $2,500-4,000 (refurbished/rebuilt)

Typical onset: 70,000-130,000 mi

Symptoms: Low oil warning light between changes (1+ quart per 1,000 miles), Blue smoke on cold start or hard acceleration, Fouled spark plugs causing misfires, Carbon buildup on intake valves worsening consumption

Fix: Piston ring wear is the culprit—rings lose tension due to direct-injection carbon buildup and fuel dilution. Requires engine teardown: pistons, rings, cylinder honing, valve cleaning. 20-28 hours labor. Some owners band-aid with catch cans and frequent oil changes.

Estimated cost: $4,500-7,500 (full piston/ring job), $800-1,200 (catch can + walnut blasting as preventive)

Typical onset: 50,000-90,000 mi

Symptoms: Clunking when shifting from Park to Drive or Reverse, Excessive vibration at idle in Drive, Lurching sensation during acceleration, Visible sagging or torn rubber on mount inspection

Fix: Replace front and rear transmission mounts. Hydraulic mounts are common failure point. 2.5-3.5 hours labor depending on access (AWD models take longer).

Estimated cost: $600-1,000

Typical onset: 80,000-140,000 mi

Symptoms: High-pitched whine when turning, especially when cold, Stiff or heavy steering feel, Power steering fluid leak from pump or high-pressure line, Groaning noise at full lock

Fix: Replace power steering pump and flush system. Pump bearing failure is common on this platform. 2.5-3 hours labor. Check for metal contamination in old fluid—if present, replace rack too (add 8-10 hours).

Estimated cost: $800-1,200 (pump only), $2,200-3,500 (pump + rack)

Symptoms: Water pooling in front footwells after rain/car wash, Headliner sagging or staining near A-pillars, Musty smell in cabin, Wet carpet under floor mats (driver/passenger side)

Fix: Clear sunroof drain tubes (four corners of sunroof cassette). Tubes exit behind front fender liners and at rear quarter panels. Use compressed air or flexible wire. If tubes are cracked/separated inside body panels, requires headliner removal. 1-2 hours if accessible, 6-8 hours if tubes need replacement.

Estimated cost: $150-300 (cleaning), $800-1,400 (tube replacement with headliner removal)