1997 MITSUBISHI DIAMANTE

Typical onset: 80,000-150,000 mi

Symptoms: Pink or milky transmission fluid on dipstick, Coolant level dropping without external leaks, Transmission slipping, delayed engagement, or complete failure, Overheating transmission or engine

Fix: Radiator replacement is mandatory (internal cooler fails), plus full transmission flush if caught early. If coolant entered transmission, expect complete rebuild or replacement. Often requires new radiator, transmission rebuild/replacement, and cooling system flush. 8-14 hours labor depending on transmission condition.

Estimated cost: $2,800-5,500

Typical onset: 60,000-100,000 mi (if never serviced)

Symptoms: No symptoms until catastrophic failure, Engine cranks but won't start (broken belt), Coolant leak from water pump weep hole, Squealing or whining noise from front of engine

Fix: This is an interference engine—belt failure destroys valves and pistons. Preventive replacement every 60k miles includes belt, tensioner, idler pulleys, and water pump. If belt breaks, expect bent valves at minimum, often full head work or short block. Preventive service: 4-5 hours. Post-failure repair: 15-25 hours.

Estimated cost: $800-1,200 (preventive), $3,500-6,500 (after failure)

Typical onset: 100,000-180,000 mi

Symptoms: Low oil pressure warning light, especially at idle when hot, Knocking or ticking noise from lower engine, Metal shavings in oil during changes, Poor oil flow observed when removing valve covers

Fix: The 6G74 is prone to sludge buildup if oil changes exceed 5k intervals or wrong oil viscosity used. Sludge starves rod and main bearings. Requires engine teardown, bearing replacement, crank polishing or replacement, thorough cleaning. Often more cost-effective to install used or rebuilt engine. 18-24 hours for in-chassis rebuild, 12-16 for engine swap.

Estimated cost: $3,200-5,800

Typical onset: 120,000-180,000 mi

Symptoms: White smoke from exhaust (coolant burning), Overheating without obvious cause, Bubbles in coolant reservoir with engine running, Loss of coolant with no visible leaks, Oil contamination in coolant or vice versa

Fix: Both heads typically need work due to V6 design heat distribution. Requires head removal, gasket replacement, resurfacing, valve job often recommended. While heads are off, timing components should be replaced. 10-14 hours labor plus machine shop time.

Estimated cost: $2,200-3,800

Typical onset: 80,000-140,000 mi

Symptoms: Clunking when shifting from Park to Drive or Reverse, Excessive vibration at idle in gear, Visible engine/transmission movement when accelerating, Shudder during hard acceleration

Fix: Front and rear transmission mounts wear out from the heavy transverse V6 and automatic transmission. Relatively straightforward replacement requiring engine support. 2-3 hours labor.

Estimated cost: $350-650

Typical onset: 90,000-150,000 mi

Symptoms: Hard starting after sitting overnight, Loss of power under acceleration or at highway speeds, Engine stumbling or surging, Check engine light with lean codes (P0171/P0174)

Fix: In-tank fuel pump works harder when filter clogs, eventually burning out pump. Filter replacement often neglected (no service reminder). Pump replacement requires tank drop. Filter: 1 hour, pump: 3-4 hours.

Estimated cost: $180-350 (filter), $650-950 (pump)