2003 Mitsubishi Diamante
The Verdict
The 2003 Mitsubishi Diamante has 69 owner complaints filed with NHTSA. The most reported issues are body (34 complaints) and engine (20 complaints). With a Klunk Score of 82/100, it earns a "Smooth Ride" rating. If you're shopping for a Mitsubishi Diamante, consider the 2004 model year which has 95% fewer complaints.
Safe Bet
The 2004 has 95% fewer complaints
View the 2004 Mitsubishi Diamante dashboard →
Klunk Score: Smooth Ride
This vehicle year has significantly fewer complaints than average. A reliable choice.
How is this calculated?
The Klunk Score ranks this vehicle year against all others in our database based on total owner complaints filed with NHTSA. 100 = fewest complaints (top tier), 0 = most complained-about. Scores above 60 are better than average; below 40 means more problems than most.
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Under the Hood
Each number is a complaint. Darker = bigger problem.
By Category
By Severity
Worst Problems
Complaints
TL* THE CONTACT OWNS A 2003 MITSUBISHI DIAMANTE EQUIPPED WITH COOPER CS3 TIRES (NA). WHILE DRIVING 25 MPH, AIR FROM THE VEHICLE'S FRONT DRIVER SIDE TIRE BEGAN TO BE RELEASED. THE CONTACT PULLED THE VEHICLE INTO A FUEL STATION/REPAIR SHOP WHERE THE TIRE WAS REPLACED. THE CONTACT TOOK THE VEHICLE TO THE INDEPENDENT MECHANIC THAT SOLD HIM THE TIRES. THE TIRES WERE MEASURED AND THE CONTACT WAS INFORMED THAT EACH OF THEM NEEDED TO BE REPLACED. THE DEALER WAS NOT CONTACTED. THE MANUFACTURER WAS NOTIFIED OF THE FAILURE. THE TIRE SIZE WAS UNKNOWN. THE APPROXIMATE TIRE FAILURE MILEAGE WAS 198,000 AND THE VEHICLE FAILURE MILEAGE WAS 216,242.
TL* THE CONTACT OWNS A 2003 MITSUBISHI DIAMANTE. THE CONTACT STATED THAT THE HEATER CORE FLUID LEAKED ONTO THE CENTRAL COMPUTER AND CAUSED THE TRANSMISSION TO FAIL. IN ADDITION, THE GEAR SHIFTER COULD NOT BE RELEASED FROM THIRD GEAR. THE VEHICLE WAS NOT TAKEN TO THE DEALER. THE VEHICLE WAS NOT REPAIRED. THE MANUFACTURER WAS MADE AWARE OF THE FAILURE. THE APPROXIMATE FAILURE AND CURRENT MILEAGE WAS 164,000. THE VIN WAS NOT AVAILABLE.
I HAVE A 2003 MITSUBISHI DIAMANTE LS WITH 71677 MILES ON IT ALL OF THE SUDDEN MY HUSBAND (THE PRIMARY DRIVER) TELLS ME THAT EVERY TIME HE GETS OUT OF THE CAR HE FEELS LIGHT HEADED AND NAUSEOUS. DAYS LATER THE FRONT WINDSHIELD STARTED FOGGING UP WHILE DRIVING AND AFTER TURNING THE CAR OFF (WHETHER IT IS WARM OR COLD OUTSIDE) I GOOGLED WHY WOULD THIS HAPPEN AND HAVE SPOKEN WITH A FEW MECHANICS AND THEY ARE TELLING ME THAT IT IS THE HEATER CORE GOING OUT, AND THAT THE REASON WHY MY HUSBAND IS GETTING LIGHT HEADED AND NAUSEOUS IS BECAUSE THERE IS ANTI-FREEZE COMING INTO THE INTERIOR OF THE CAR WHICH IS VERY DETRIMENTAL TO YOUR HEALTH. I HAVE READ A TON OF COMPLAINTS ON DIFFERENT WEBSITES AND THEY ALL SAY THE SAME THING. I CONTACTED MITSUBISHI CORPORATE TODAY AND SPOKE WITH A [XXX] IN CUSTOMER SERVICE AND EXPLAINED TO HER WHAT WAS GOING ON AND ASKED WHY MITSUBISHI HAS NOT DONE ANYTHING ABOUT THIS. FIRST BECAUSE OF THE HEALTH IMPLICATIONS, SECONDLY BECAUSE OF THE SAFETY ISSUE OF THE WINDSHIELD FOGGING UP WHILE YOU'RE DRIVING TO WHERE YOU CAN'T SEE AND THIRDLY THAT FROM READING THE COMPLAINTS, THE HEATER CORE IS RIGHT ABOVE THE COMPUTER IN THE CAR SO IF THE HEATER CORE IS LEAKING ANTIFREEZE, IT COULD FRY THE COMPUTER AND CAUSE A POSSIBLE CRASH IF THE CAR WERE TO STOP SUDDENLY. SHE SAID THAT "SEEING THAT I HADN'T HAD THE CAR INTO A DEALERSHIP IN THE LAST YEAR THAT THERE IS NOTHING THEY CAN DO ABOUT IT". I TOLD HER THAT IT JUST STARTED AND WHAT WAS I SUPPOSE TO DO, LOOK INTO MY CRYSTAL BALL AND KNOW A YEAR AHEAD OF TIME THAT THE HEATER CORE WAS GOING TO GO OUT. THIS IS LUDICROUS! ! ! MITSUBISHI KNOWS THAT THIS IS A SERIOUS ISSUE AND ARE NOT DOING ONE THING TO FIX IT (BY ISSUING A RECALL) WHERE DO WE DIAMANTE OWNERS GO TO GET SOME HELP? DO WE NEED TO FILE A CLASS ACTION LAWSUIT AS THAT SEEMS LIKE THE ONLY WAY A FIRE IS GOING TO GET LIT UNDER THEM (CORPORATIONS TEND TO ACT IF IT MEANS LOSING TONS OF MONEY) THE CAR CAN'T BE DRIVEN AND I'M STILL PAYING ON IT. HELP! INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6). *TR
TL* THE CONTACT OWNS A 2003 MITSUBISHI DIAMANTE. THE CONTACT STATED THE VEHICLE WAS CONSUMING EXCESSIVE AMOUNTS OF FUEL AND SHE WAS CONCERNED THE VEHICLE WOULD PREMATURELY RUN OUT OF FUEL WHILE DRIVING. THE VEHICLE WAS TAKEN TO AN INDEPENDENT REPAIR SHOP WHERE THE CONTACT WAS TOLD THAT THE INTAKE AIR TEMPERATURE SENSOR WOULD NEED TO BE REPLACED. THE VEHICLE WAS NOT REPAIRED. THE FAILURE MILEAGE WAS 60,000 AND THE CURRENT MILEAGE WAS 70,000.
TL- THE CONTACT OWNS A 2003 MITSUBISHI DIAMANTE. THE CONTACT STATED THAT THE NEUTRAL LIGHT ON THE VEHICLE STARTED FLASHING ON AND OFF AND HE NOTICED A SMELL OF COOLANT. HE NOTICED THAT THE COOLANT WAS LEAKING ONTO THE FLOORBOARD OF THE VEHICLE. THE FAILURE PROGRESSES UNTIL THE VEHICLE WILL NOT START. THE VEHICLE WAS TAKEN TO A DEALER AND THE OWNER WAS ADVISED THE FAILURE WAS THE A.T. CONTROL RELAY. CODE P-1751. THE FAILURE HAS NOT BEEN REPAIRED. THE CURRENT AND FAILURE MILEAGE IS APPROXIMATELY 60,000. RD
TL* THE CONTACT OWNS A 2003 MITSUBISHI DIAMANTE. THE CONTACT STATED HE NOTICED AN UNUSUAL ODOR OF COOLANT AND THE NEUTRAL INDICATOR BEGAN SPORADICALLY ILLUMINATING. UPON FURTHER INSPECTION, THE CONTACT FOUND COOLANT LEAKING ONTO THE FLOORBOARD. IN ADDITION, THE VEHICLE WOULD INTERMITTENTLY FAIL TO START. THE DEALER PERFORMED A DIAGNOSTIC TEST AND DETERMINED THE FAILURE WAS CAUSED BY THE A.T. CONTROL RELAY AND PRODUCED CODE P1751. THE VEHICLE WAS NOT REPAIRED AND THE VIN WAS NOT AVAILABLE. THE FAILURE AND CURRENT MILEAGES WERE APPROXIMATELY 60,000. UPDATED 10/27/10. *LJ
INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6). THIS CONCERNS MY 2003 MITSUBISHI DIAMANTE. IT HAS LESS THAN 50,000 MILES ON IT AND IT HAS SUDDENLY STARTED SPEWING A LIGHT FILM ON THE INSIDE OF MY FRONT WINDSHIELD SO THAT I CANNOT SEE WELL...AND NOT AT ALL WHEN I AM HEADED INTO THE SUN. I HAVE CHECKED ON THE INTERNET AND A LOT OF PEOPLE ARE HAVING THE SAME PROBLEM WITH MITSUBISHI DIAMANTES GOING BACK SEVERAL MODEL YEARS. ALL DIAMANTES NEED TO BE RECALLED AND THE HEATER CORE AND/OR ITS O RINGS FIXED OR REPLACED. IF THIS DOESN'T HAPPEN, PEOPLE WILL DIE WHEN THEY SUDDENLY CANNOT SEE THE ROAD THROUGH THEIR FRONT WINDSHIELD. [XXX] *TR *DT
I HAVE A 2003 MITSUBISHI DIAMANTE WITH 60,000 PLUS MILES. FOR THE PAST SEVERAL MONTHS I HAVE NOTICED A STRONG SMELL OF ANTI-FREEZE COMING FROM THE VENTS AND THE WINDOWS CONSTANTLY FOGGING UP, SOMETIMES TO THE POINT THAT I CANNOT SEE TO DRIVE. I HAVE READ MANY SIMILAR COMPLAINTS AND AGREE WITH OTHERS THAT MITSUBISHI NEEDS TO ISSUE A RECALL FOR THE HEATER CORE, AS I AM SURE THIS IS THE PROBLEM. I HAVE YET TO TAKE MINE IN TO GET IT REPAIRED, SO I DON'T HAVE A COST QUOTE AT THIS TIME. *TR
ANTI-FREEZE LEAK ON CARPET PASSENGER SIDE NEAR FIREWALL FOGGED UP WINDOWS CHECK ENGINE LIGHT COMES ON AND OFF DUE TO THE LEAK THE ECU STARTED WORKING AWFUL. *TR
I PURCHASED A USED 2003 MITSUBISHI DIAMANTE FROM BANKSTON DODGE IN 2007. IT WAS CLEAN AND RAN WELL. THERE WAS AN UNUSUAL ODOR INSIDE, BUT SMELLED AS IF IT COULD HAVE BEEN WHAT THE DEALERSHIP USED TO CLEAN THE INSIDE. IT TURNED OUT TO BE ANTI-FREEZE. THE VEHICLE HAD A HEATER CORE LEAK PRIOR TO OUR PURCHASE. RECENTLY THE GAS GAUGE HAS STOPPED WORKING. *TR
I OWN A 2003 DIAMANTE WITH ABOUT 60,000 MILES ON IT. MY WINDOWS CONTINUALLY FOG UP WHILE DRIVING OR PARKED AND THE DEFROSTER/VENTS DOES NOT ELIMINATE THE FOG AT ALL, MAKING DRIVING VERY DIFFICULT AND DANGEROUS ESPECIALLY IN RAINY WEATHER AND DURING THE NIGHTTIME. THE SMELL OF ANTIFREEZE IS EXTREMELY STRONG INSIDE THE VEHICLE. I HAD A PROBLEM WITH MY TRANSMISSION SHIFTING AND THE LIGHT AROUND THE "N" ON THE INSTRUMENT PANEL WAS FLASHING. THE MECHANIC SAID MY HEATER CORE WAS LEAKING COOLANT ONTO THE TRANSMISSION CONTROL MODULE CAUSING IT TO MALFUNCTION. I WAS TOLD THAT EVEN THOUGH I PAID FOR AND HAVE AN EXTENDED WARRANTY ON THIS VEHICLE IT WOULD NOT BE COVERED BECAUSE THE HEATER CORE LEAKING IS WHAT CAUSED THE TRANSMISSION CONTROL MODULE TO FAIL. THE HEATER CORE WAS REPLACED ALONG WITH THE CONTROL MODULE AND THE RELAY WITH A COST OF OVER 2,500 DOLLARS. IT SEEMS LIKE A PROBLEM LIKE THIS THAT IS EXTREMELY COMMON IS THESE VEHICLES, CREATES SAFETY AND HEALTH HAZARDS, AND VERY EXPENSIVE TO FIX SHOULD BE RECALLED AND COVERED UNDER WARRANTY. *TR
HEATER CORE LEAKAGE CAUSING SMOKE AND ANTIFREEZE ODOR TO COME OUT OF CAR VENTS AND UNDERNEATH DASH BOARD (PASSENGER SIDE). THERE IS A RISK OF ACCIDENT, PERSONAL INJURY, OR DEATH BECAUSE USE OF A/C, HEATER, AND DEFROST IS NOT AVAILABLE WHEN WINDSHIELDS AND WINDOWS FOG UP. *TR
I OWN A 2003 MITSUBISHI DIAMANTE, AROUND 60K MILES I STARTED NOTICING A SWEET SMELL FROM THE VENTS AND A CONSTANT FOG WHEN THE HEAT OR AIR WAS TURNED ON IN THE CAR. AFTER TAKING MY CAR TO THE MECHANIC I WAS TOLD THAT MY HEATER CORE WAS BUSTED. MY CAR ALSO SDRIVING IN "SAFE MODE" MEANING I CAN ONLY RUN IN SECOND GEAR WHICH IS BURNING A TANK OF GAS EVERY THREE DAY, I LOVE 10 MILES FROM WORK. MY CAR FLASHED IN NEUTRAL WILL IN DRIVE. AFTER RESEARCHING MY PROBLEMS I'VE NOTICE WELL OVER 1000 POSTED VIA INTERNET FROM OTHER MITSUBISHI DIAMANTE OWNERS HAVING THE SAME ISSUE. ITS HARD TO BELIEVE THIS VEHICLE HAS NOT BE RECALLED. THERE ARE GREAT RISKS OF INHALING ANTI FREEZE WHICH IS SEEPING INTO THE CAR THROUGH THE FLOOR BOARDS AND VENTS. I HAVE AN ASTHMATIC CHILD WHO HAS BEEN DRIVING IN THE CAR UNTIL THE PROBLEM WAS BROUGHT TO MY ATTENTION. THIS LEAK MAY ALSO MAKE THE COMPUTER SYSTEM IN THE VEHICLE GO OUT. SOMETHING NEEDS TO BE DONE BEFORE AN ACCIDENT IS CAUSED OR A LIFE IS TAKEN. *TR
MY TRANSMISSION RELAY WENT OUT DUE TO A LEAK HEATER CORE. THE CORE HAS BEEN LEAKING FOR SOME TIME AND HAS FOGGED MY WINDOWS SO BAD I COULD NOT SEE AT TIMES, HAVING TO PULL OVER AND WIPE OFF THE FILM. THIS IS A SERIOUS PROBLEM WITH THESE CARS. *TR
I OWN A 2003 DIAMANTE MITSUBISHI. THE PROBLEM STARTED WITH A CHECK ENGINE LIGHT COMING ON, FOGGING THE WINDOW WITH A FOWL TOXIC SMELL THEN THE CAR WOULD NOT HARDLY MOVE OUT GEAR. I WAS TOLD THAT THE CAR'S HEATER CORE LEAKED ONTO THE COMPUTER WHICH CAUSED THE TRANSMISSION RELAY TO SHORT OUT DO TO THE COMPUTER FAILING. THE COMPUTER WAS STILL UNDER WARRANTY AT 78,000 MILES BUT I STILL HAD TO PAY FOR THE NEW COMPUTER SYSTEM BECAUSE I WAS TOLD THAT IT WAS THE HEATER CORE THAT CAUSED THE COMPUTER TO FAIL. THIS IS SUCH A POOR DESIGN! THE COMPUTER SHOULD HAVE BEEN PROTECTED IN SUCH A CASE...FUNNY THING IT IS NOW THAT I HAVE HAD TO REPLACE A HEATER CORE, A COMPUTER AND A TRANSMISSION RELAY AT A CUT WRENCHING COST OF $3,675.58. I WROTE A LETTER TO THE PRESIDENT OF NORTH AMERICA MITSUBISHI THAT THE HEATER CORE SHOULD BE A RECALL BUT TO NO AVAIL. I HAVE ALL MAINTENANCE RECORDS ON THE DIAMANTE SO THAT WAS NOT WHAT CAUSED THIS HEATER FAILURE. I DO HAVE THE COMPUTER THAT WAS REPLACED. IT IS NOW APRIL AND THE CHECK ENGINE LIGHT HAS COME BACK ON...NOW WHAT? AJ *TR
DRIVING ALONG AND WINDOWS STARTED TO FOG UP, AND STARTED SMELLING A ODD ODOR. FOUND OUT MY HEATER CORE WAS BAD. APPARENTLY CRACKED FOR NO REASON. RIGHT NOW BY-PASSED THE HEATER CORE BECAUSE MITSUBISHI DEALER QUOTED $1,800.00 TO FIX IT. IT APPEARS TO BE A BIG PROBLEM WITH THE DIAMANTE'S. *TR
I HAVE 2003 MITSUBISHI DIAMANTE. MY "CHECK ENGINE" LIGHT CAME ON, SO I TOOK IT IN FOR SERVICE, AND MY HEATER CORE WAS LEAKING ON MY COMPUTER...NOW IT'S GOING TO COST ME AROUND 3,500 DOLLARS....THIS IS A VERY FLAWED DESIGN. THERE SHOULD BE A RECALL ON THIS ITEM. *TR
I BOUGHT AN 2003 MITSUBISHI DIAMANTE IN 2005. MY WIFE AND I NOTICED AN OCCASIONALLY "SYRUP" SMELL, BUT DIDN'T THINK MUCH OF IT. THIS WEEK END (MARCH 08)ANTI-FREEZE (COOLANT) BEGAN TO COME OUT OF THE VENTS IN A MIST. IT EVEN TURNED THE BOTTOM HALF OF MY FRONT WINDSHIELD GREEN CREATED A FILM ON THE WINDOWS WHICH MADE IT HARD TO SEE. I HAVE A NEW BORN CHILD THAT IS NOW SICK AS WELL MYSELF AND MY 2 1/2 YEAR OLD. THEY HAVE A DOCTORS APPOINTMENTS TOMORROW AND I HOPE THEY ARE NOT SICK FROM THE CAR. ESTIMATED COST TO FIX WAS ABOUT $1150. *TR
I OWN A 2003 MITSUBISHI DIAMANTE LS WITH 70,000. I PURCHASED THE CAR FROM THE DEALERSHIP BRAND NEW. IN NOVEMBER 2007, THERE WAS A STRONG SMELL OF ANTIFREEZE IN THE CAR. AFTER SOME INVESTIGATION, IT WAS DISCOVERED THERE WAS A LEAK IN THE HEATING CORE, WHICH WAS CAUSING THE ANTIFREEZE TO LEAK OUT OF THE COMPARTMENT AND INTO THE CABIN OF THE CAR...NEEDLESS TO SAY, THE CAR IS UNDRIVEABLE BECAUSE OF THE HEALTH RISKS ASSOCIATED WITH BREATHING ANTIFREEZE. ESTIMATED REPAIRS ARE AROUND $1500. THIS IS COMPLETELY RIDICULOUS!!!! I AM OUTRAGED TO SEE THAT SO MANY 2003 DIAMANTE OWNERS ARE HAVING THE SAME PROBLEM. I BELIEVE AN INVESTIGATION NEEDS TO BE CONDUCTED, AND MITSUBISHI MOTORS SHOULD BE HELD ACCOUNTABLE FOR THIS!!! *TR
37813 MILES. HEATER CORE LEAKING. NOTICE THE SWEET SMELL AND NOW OVERHEATING OCCURS. *TR
69 total