2010 MERCEDES-BENZ ML350 W164

Typical onset: 40,000-100,000 mi

Symptoms: Check engine light with camshaft position sensor codes (P0016, P0017), Metallic rattling on cold start that may disappear when warm, Sudden loss of power or complete engine failure, Metal shavings in oil during changes

Fix: The plastic balance shaft gears strip teeth, sending debris through the entire engine and destroying bearings, pistons, and cylinder walls. Requires complete engine rebuild or replacement. 25-35 labor hours for rebuild, 18-22 hours for used engine swap. Many shops won't touch rebuilds due to liability.

Estimated cost: $8,000-15,000

Typical onset: 70,000-120,000 mi

Symptoms: Pink or milky residue in coolant expansion tank, Transmission slipping or delayed engagement, Overheating transmission or engine, Sweet smell from exhaust (coolant burning)

Fix: The transmission oil cooler inside the radiator develops internal leaks, mixing coolant and ATF. Once contaminated, the transmission requires complete flush or replacement. Must replace radiator and perform multiple transmission fluid flushes minimum. 8-12 hours labor if caught early, 20+ hours if transmission damaged.

Estimated cost: $1,500-6,000

Typical onset: 60,000-100,000 mi

Symptoms: Clunking when shifting from park to drive or reverse, Excessive vibration at idle in gear, Visible transmission sag when inspected on lift, Harsh engagement into gear

Fix: The hydraulic transmission mount collapses, allowing excessive drivetrain movement. Requires support of transmission and subframe access. 2-3 hours labor with proper tools.

Estimated cost: $400-700

Typical onset: 80,000-150,000 mi

Symptoms: Oil seepage from head gasket area, White smoke on startup (coolant entering cylinders), Coolant loss with no external leaks, Misfires on multiple cylinders

Fix: The M272 uses torque-to-yield head bolts that stretch over time, losing clamping force. Leads to head gasket failure. Requires both heads removed, resurfacing, new bolts, and full timing chain service while apart. 18-24 hours labor. Often discovered during balance shaft repair.

Estimated cost: $4,500-7,000

Typical onset: 60,000-90,000 mi

Symptoms: Oil consumption (1 quart per 1,000 miles or more), Rough idle or stumbling, Oil in intake manifold or throttle body, Whistling noise from engine bay

Fix: The PCV separator and valve cover breathers clog with sludge, causing excessive crankcase pressure that pushes oil past seals and rings. Requires both valve covers off to replace separator and breathers. 4-6 hours labor. Preventive maintenance item before balance shaft work makes sense.

Estimated cost: $800-1,400

Typical onset: 70,000-110,000 mi

Symptoms: Clunking over bumps from front suspension, Wandering steering or poor tracking, Uneven front tire wear, Vibration at highway speeds

Fix: The forward lower control arm bushings tear, allowing excessive movement. Mercedes doesn't sell bushings separately—requires complete control arm replacement both sides. 3-4 hours labor plus alignment.

Estimated cost: $900-1,500