2001 MITSUBISHI MONTERO SPORT

Typical onset: 80,000-150,000 mi

Symptoms: sudden severe knocking from bottom end, metal shavings in oil, loss of oil pressure, complete engine seizure without warning, check engine light may or may not precede failure

Fix: The 6G72 3.0L V6 suffers catastrophic crankshaft and connecting rod bearing failure, often without warning. Oil starvation to cylinders 2/5 is design-related. Requires complete engine rebuild or replacement. Budget 20-30 labor hours for rebuild, 12-16 hours for used engine swap. Many owners opt for junkyard engines due to cost.

Estimated cost: $3,500-6,500

Typical onset: 100,000-160,000 mi

Symptoms: harsh 2-3 shift or slipping in 2nd gear, delayed engagement into drive or reverse, transmission overheating, shuddering during acceleration, complete loss of forward gears

Fix: The 4-speed automatic (especially in 4WD models) develops worn clutch packs, valve body issues, and overheating problems. The internal transmission oil cooler in the radiator can fail and cross-contaminate coolant with ATF, destroying the transmission. Rebuild requires 12-18 hours; replacement 8-12 hours. Always replace radiator simultaneously if cooler failed.

Estimated cost: $2,200-4,000

Typical onset: 90,000-140,000 mi

Symptoms: milky/pink transmission fluid, strawberry milkshake appearance in coolant reservoir, transmission slipping after overheating, coolant loss with no external leaks, transmission failure following coolant contamination

Fix: Internal transmission cooler inside radiator fails, mixing ATF and coolant. This ruins both the transmission and potentially the engine. Requires immediate radiator replacement, complete transmission fluid system flush (if caught early), or full transmission rebuild if contamination proceeded. Prevention: install external transmission cooler and bypass internal cooler. 4-6 hours if only radiator, add 12-18 hours if transmission damaged.

Estimated cost: $800-4,500

Typical onset: 80,000-130,000 mi

Symptoms: gear oil dripping from front of rear differential, oil spots on driveway under center of vehicle, whining noise from rear axle if run low on oil, visible oil coating on differential housing

Fix: Pinion seal deteriorates and leaks gear oil. Requires driveshaft removal, pinion nut removal with proper torque specs on reassembly to maintain bearing preload. If ignored, can lead to differential bearing failure. 2-3 hours labor plus fluid.

Estimated cost: $350-550

Typical onset: 100,000-150,000 mi

Symptoms: 4WD will not engage or disengage, flashing 4WD indicator lights, grinding noise when attempting to shift into 4WD, stuck in 4WD or 2WD mode, no response from 4WD selector switch

Fix: Electric shift motor on transfer case fails due to corrosion or internal wear. Motor is externally mounted and relatively accessible. Some cases require transfer case removal for internal fork inspection. 2-4 hours labor depending on whether internal components need service.

Estimated cost: $450-900

Typical onset: 70,000-110,000 mi

Symptoms: clunking over bumps from front suspension, steering wander or looseness, uneven tire wear on inside edge, visible play when prying on tire, vehicle pulls to one side

Fix: Lower ball joints wear prematurely, especially with larger tires or off-road use. Failure can cause loss of control. Ball joints are pressed into lower control arms; many techs replace entire control arm assemblies for reliability. Alignment required after. 3-4 hours both sides with alignment.

Estimated cost: $600-1,000

Typical onset: 90,000-140,000 mi

Symptoms: exhaust tick or tapping at cold start that quiets when warm, hissing sound from engine bay during acceleration, smell of exhaust in cabin, visible cracks on manifold surface, failed emissions test

Fix: Cast iron exhaust manifolds develop cracks from heat cycling, typically on rear bank (firewall side). Access is difficult; requires 6-8 hours labor due to tight clearances. Aftermarket headers are common upgrade but may not be emissions-legal in all states.

Estimated cost: $700-1,200