2004 INFINITI M45

Typical onset: 80,000-140,000 mi

Symptoms: Rattling noise on cold starts that may disappear when warm, Check engine light with cam/crank correlation codes (P0011, P0021, P0340), Sudden catastrophic failure: metal shavings in oil, loss of power, engine seized, Oil starvation damage to bearings, cylinders, and crankshaft

Fix: Upper timing chain guides disintegrate, sending plastic chunks through the oil system and clogging pickup screens. This starves the engine of oil. Once rattling starts, you have limited time. Preventive timing chain service with guides/tensioners runs 18-22 hours labor. Full engine rebuild after failure: 35-45 hours labor plus machine work, or used engine swap at 20-25 hours labor.

Estimated cost: $3,500-6,000 preventive service; $8,000-14,000 rebuild after failure

Typical onset: 70,000-120,000 mi

Symptoms: Transmission slipping, delayed engagement, or flaring between shifts, Pink milkshake appearance in coolant overflow tank, Transmission overheating warnings on dash, Strawberry milkshake in transmission fluid dipstick

Fix: The transmission cooler inside the radiator fails internally, allowing coolant and ATF to mix. Coolant destroys the transmission from the inside. Requires radiator replacement, external transmission cooler installation, full transmission flush (often multiple flushes), and frequently a transmission rebuild or replacement. Transmission R&R is 8-12 hours; add rebuild time or use a reman unit. Always install an external cooler during repair.

Estimated cost: $4,500-7,500 with transmission rebuild; $2,500-3,500 if caught early with flush only

Typical onset: 60,000-100,000 mi

Symptoms: Clunking when shifting from Park to Drive or Reverse, Excessive vibration at idle in gear, Drivetrain shudder during acceleration, Visible sagging or torn rubber in mount

Fix: The rear transmission mount deteriorates and tears, allowing excessive drivetrain movement. This is a known weak point on the VK45DE/RE5R05A combo. Replacement is straightforward but requires supporting the transmission. 2-3 hours labor for mount replacement; inspect all motor mounts while you're there.

Estimated cost: $350-600

Symptoms: Brake lights stay on constantly, draining battery, Brake lights don't illuminate when pedal is pressed, Inability to shift out of Park, Cruise control won't set or cancels randomly

Fix: NHTSA recall for brake light switch that can fail in multiple ways, creating safety hazards and preventing shifter interlock from releasing. Check if recall 04V-315 was completed. Switch replacement is simple: 0.5-1.0 hour labor. Should be a free dealer fix if recall not yet completed, but verify recall status first.

Estimated cost: $150-250 if not covered by recall

Typical onset: 80,000-130,000 mi

Symptoms: Oil smell in cabin or when parked, Visible oil seepage on sides of engine block, Oil drips on driveway, Low oil level between changes

Fix: The VK45DE develops leaks from valve cover gaskets and camshaft seals as it ages. Not immediately dangerous but creates mess and can drip onto exhaust components. Both valve covers require removal of ignition coils and various hoses. 4-6 hours labor for both covers and cam seals if doing it all at once.

Estimated cost: $800-1,400

Typical onset: 90,000-140,000 mi

Symptoms: Hard starting, especially when hot, Stumbling or hesitation under acceleration, Stalling at idle or when coming to a stop, Fuel pump whining noise from rear of vehicle

Fix: The in-tank fuel pump assembly (with integrated filter) can fail, causing drivability issues. The filter is not separately serviceable—entire pump assembly must be replaced. Requires dropping the fuel tank or removing rear seat and accessing through top. 3-4 hours labor with top access, 5-6 hours if tank drop is needed.

Estimated cost: $800-1,300