NHTSA lists 3 safety recalls and 133 owner complaints for the 2002 Mitsubishi Diamante. Most complaints involve visibility (72) and engine and engine cooling (43). The EPA rates it 18 mpg combined.
CERTAIN PASSENGER VEHICLES FAIL TO CONFORM TO THE REQUIREMENTS OF FEDERAL MOTOR VEHICLE SAFETY STANDARD NO. 208, 'OCCUPANT CRASH PROTECTION.' THE BILINGUAL ENGLISH/SPANISH REMOVABLE AIR BAG WARNING LABELS AFFIXED TO THE DASH AND TO THE SUNVISOR DO NOT MEET THE SIZE REQUIREMENTS OF THE STANDARD.
CERTAIN SPORT UTILITY AND PASSENGER VEHICLES FAIL TO COMPLY WITH FEDERAL MOTOR VEHICLE SAFETY STANDARD NO. 225, "CHILD RESTRAINT ANCHORAGE SYSTEMS." THE OWNER'S MANUAL DOES NOT CONTAIN A STEP-BY-STEP DESCRIPTION FOR HEADREST ADJUSTMENT WHEN INSTALLING A CHILD RESTRAINT SYSTEM (CRS) TETHER STRAP.
ON CERTAIN PASSENGER VEHICLES, THE MAIN UNDER HOOD ELECTRICAL WIRING HARNESS MAY HAVE INSUFFICIENT CLEARANCE BETWEEN THE ENGINE CONTROL HARNESS AND THE EXHAUST HEAT SHIELD. AS A RESULT, THE HARNESS COULD COME IN CONTACT WITH THE HEAT SHIELD, WHICH COULD RESULT IN MELTING OF THE HARNESS INSULATION.
Complaints are unverified owner reports to NHTSA and are not normalized for sales volume. One complaint can cite several components.
“THE HEATER CORE IS AN EXTREMELY DANGEROUS PROBLEM. THE WINDOWS IN THE CAR FOG UP SO BAD I COULDNT DRIVE THE CAR...HAD TO PULL OVER AND WIPE THE WINDOWS DOWN. BUT THE THING IS...I DIDNT KNOW WHAT THE PROBLEMS WAS...UNTIL I REALIZED THE WINDOWS WERENT JUST BEING FOGGED BY THE COLD, ECT IT WAS A TOXIC MIST FROM A HEATER CORE PROBLEM...I PULLED OVER 2 TIMES BECAUSE I GOT SICK...I NOTICED A MIST COMING OUT OF THE VENTS....SO ALL IN ALL I CALLED MITSUBISHI AND THEY REFUSE TO DO ANYTHING ABOUT THIS.THIS HEATER CORE PROBLEM CAN LEAD TO ACCIDENTS, SICKNESS, AND OTHE EXPENSIVE PROBLEMS IN THE CAR! THE FUMES ARE EXTREMELY TOXIC!!! THERE ARE 1000'S OF COMPLAINTS AND BLOGS ABOUT THIS PROBLEM...I'M SURE THERE ARE 100,000+ COMPLAINTS ABPOUT THIS PROBLEM. AND MITSUBISHI REFUSES TO HELP OR DO ANYTHING ABOUT THIS. I TOLD THEM, IS THIS GONNA TAKE A FATAL ACCIDENT FOR THEM TO DO SOMETHING?" THEY REPLIED, "IM NOT ANSWERING THAT!" I TOLD THEM THAT THEY SHOULD HAVE RECALLED THIS PROBLEM. THEY REPLIED, "SORRY BUT YOUR WARRANTY IS UP WE CAN'T DO NOTHING ABOUT IT." THIS HEATER CORE PROBLEMS LEADS TO FAULTY TRANSMISSION PROBLEMS, ELECTRICAL PROBLEMS, HAZERDOUS PROBLEMS, SICKNESS,…”
“TL* THE CONTACT OWNS A 2002 MITSUBISHI DIAMANTE. THE CONTACT STATED THAT WHILE DRIVING AT 75 MPH, THE CONTACT ATTEMPTED TO BRAKE BUT THE BRAKES FAILED TO RESPOND WITHOUT ANY WARNINGS. THE VEHICLE CRASHED INTO A PASSENGER VAN. THE VEHICLE WAS DESTROYED. THE CONTACT MENTIONED THAT TWO MONTHS PRIOR TO THE FAILURE THE CHECK ENGINE LIGHT HAD ILLUMINATED. THE VEHICLE WAS TAKEN TO AN INDEPENDENT MECHANIC FOR DIAGNOSIS AND WAS INFORMED THAT THE VEHICLE MISFIRES, NEEDED SPARK PLUGS, A FUEL PUMP, A FUEL INJECTOR, AN EGR VALVE, AND THE ENGINE SURGED ERRATICALLY. THE FAILURE AND CURRENT MILEAGE WAS 140,000. UPDATED 12/06/12*LJ UPDATED 12/6/2012 *JS”
“I WAS DRIVING MY MITSUBISHI ACROSS THE UNIVERSITY BRIDGE ON 7-28-2017 AND SUDDENLY THE TRANSMISSION WENT OUT AND I WAS STUCK AND HAD NO POWER OF MOVEMENT,MY WIFE AND 3 Y.O.CHILD WERE PASSENGERS IN THE CAR,LUCKILY THE STATE PATROL CAME AND ASSISTED US.THE DEALER TOLD US THAT THIS CAR WAS MECHANICALLY SOUND AND HAD NO PROBLEMS OR ISSUES.THEY LIED TO US AND BY DOING SO THEY PUT OUR LIVES IN DANGER.THE DRIVERS SIDE AIR BAG WAS ALSO MISSING WHEN WE PURCHASED THE CAR.”
Towing, payload and dimensions aren’t in the EPA or NHTSA data, so we don’t list them.
| Version | City | Hwy | Comb. | Fuel / yr | CO₂ g/mi |
|---|---|---|---|---|---|
| Diamante Auto 4-spd, 6 cyl, 3.5 L · Front-Wheel Drive | 16 | 23 | 18 | $4,200 | 494 |
| Item | Miles | Time | Note |
|---|---|---|---|
| Engine oil & filter | 5,000–10,000 mi | 6–12 months | Follow the oil-life monitor if fitted |
| Tire rotation | 5,000–7,500 mi | Every oil change | Check pressure monthly |
| Engine air filter | 15,000–30,000 mi | 1–2 years | Sooner in dusty areas |
| Cabin air filter | 15,000–25,000 mi | 1–2 years | |
| Brake fluid | — | 2–3 years | Absorbs moisture over time |
| Coolant | 60,000–100,000 mi | 5–10 years | Long-life coolants last longer |
| Spark plugs | 60,000–100,000 mi | — | Iridium/platinum plugs at the long end |
| 12V battery | — | 3–5 years | Heat shortens battery life |
3 safety recalls as of Nov 12, 2026, according to NHTSA. Recall repairs are free at a dealer. Check your VIN to see whether your car is included and whether the repair was done.
Owners filed 133 complaints with NHTSA. The most-cited components are visibility (72), engine and engine cooling (43), power train (10). Complaints are unverified owner reports and aren't adjusted for how many cars were sold.
The EPA rates the 2002 Mitsubishi Diamante at 18 mpg combined, depending on engine and drivetrain (1 version rated).