1992 MITSUBISHI DIAMANTE

Typical onset: 80,000-140,000 mi

Symptoms: Rapid oil consumption (quart per 500-1000 mi), Rod knock or main bearing noise on cold start, Metal shavings in oil filter, Low oil pressure warning at idle, Engine seizure if driven with low oil

Fix: These engines sludge badly if oil changes are stretched beyond 3,000 mi or if conventional oil is used. Once bearings are scored, you're looking at a full rebuild (crank polish/undersize bearings, all rod and main bearings, new rings, head gasket set, oil pump). Total job is 18-24 labor hours. Many shops recommend a low-mile junkyard engine swap instead due to core condition—swap is 12-16 hours but you're gambling on the donor's history.

Estimated cost: $3,500-6,500

Typical onset: 70,000-120,000 mi

Symptoms: Pink or milky ATF in radiator overflow, Coolant in transmission pan (strawberry milkshake fluid), Harsh or delayed shifts after coolant mixing, Transmission overheating, Complete trans failure within 500 miles if contamination not caught

Fix: Steel cooler lines rust through where they enter the radiator, allowing coolant and ATF to mix. This kills the F4A33 transmission rapidly. Fix requires new radiator (cooler is integral), all cooler lines, full trans flush or rebuild if contamination occurred. If caught early (lines leaking externally), just lines and radiator: 4-5 hours. If fluid mixed, add trans rebuild: total 18-22 hours.

Estimated cost: $800-1,200 (early catch), $3,200-4,800 (with trans rebuild)

Typical onset: 90,000-150,000 mi

Symptoms: White smoke from exhaust on startup, Coolant loss with no visible leaks, Overheating under load, Bubbles in coolant reservoir when running, Rough idle or misfire on one bank

Fix: The SOHC 6G72 is known for head gasket leaks between cylinders and coolant jackets, often both banks simultaneously. Requires heads off, resurface (usually warped .008-.015 in.), new gaskets, timing belt/water pump while you're in there, all coolant hoses. Job is 14-18 hours. If heads are cracked (check with magnaflux), add $400-600 per head for used replacements.

Estimated cost: $2,800-4,200

Typical onset: 100,000+ mi or age-related

Symptoms: 4WS warning light on dash, Wandering at highway speeds, Clunking from rear on turns (rear steer rack), Front-end shimmy or vibration, Visible rust perforation on front subframe mounts

Fix: 4WS-equipped models have a rear steering rack that fails electrically or mechanically; rack itself is NLA, so most shops disable the system (mechanical lock kit, 2 hours, $200-400). Separate issue: front subframe mounts rust out in salt states, causing alignment problems and unsafe handling. Subframe removal, welding in reinforcement plates, and reassembly is 8-12 hours if caught before catastrophic failure.

Estimated cost: $300-600 (4WS disable), $1,200-2,000 (subframe repair)

Typical onset: 80,000-130,000 mi

Symptoms: Hard starting when hot, Stalling at idle after warm-up, Loss of power above 3/4 throttle, Surging or bucking under load, No-start after sitting (pump fails to prime)

Fix: In-tank pump fails from running on old fuel or clogged sock filter; external inline filter (under car near tank) also clogs and is often overlooked. Replace both: pump is 3-4 hours (tank drop), filter is 0.5 hour. Pump assembly includes sending unit; aftermarket quality is hit-or-miss, OEM is extinct, so expect comebacks.

Estimated cost: $450-750

Typical onset: 60,000-100,000 mi

Symptoms: Clunk when shifting from Park to Drive/Reverse, Excessive vibration at idle in gear, Shifter jumps or feels loose, Engine rocks visibly when revved in Park

Fix: Hydraulic engine mounts and transmission mount (rear transaxle mount) fail, allowing driveline to move excessively. Causes harsh engagement and can accelerate CV axle wear. Replace all three mounts: 2.5-3.5 hours. Use OEM-equivalent; cheap aftermarket mounts fail in 12 months.

Estimated cost: $350-600