Total Complaints
26 filings
MITSUBISHI DIAMANTE · model year
26 NHTSA complaints for this specific cohort.
NHTSA overall rating
Not crash-tested
New Car Assessment Program
The 1999MITSUBISHIDIAMANTE carries 26 consumer safety complaints in NHTSA's Office of Defects Investigation database for this specific model-year cohort. Within that volume, owners reported 0 crashes, 0 fires, 0 injuries, and 0 fatalities. No NCAP 5-star crash-test rating is available for this model year in the federal database.
Component-level analysis is where model-year complaints become actionable: the top complaint category for the 1999 DIAMANTE is visibility:defroster/defogger/hvac system:heater core with 8 filings, followed by suspension (2) and engine and engine cooling:cooling system (2). Concentration in one or two component groups is the classic signature of a systemic defect; a flat distribution usually reflects normal aging, warranty complaints, or isolated build-plant variability.
NHTSA currently has 14 investigation files overlapping the 1999 DIAMANTE. Owners comparing this cohort against neighboring years should pair the counters above with the complaint-by-year trend on the parent model page — a spike in a single year often tracks to a platform refresh, a new transmission supplier, or an updated ECU calibration. Use the related-complaint feed below to read raw owner narratives before deciding whether any pattern here affects your specific use case.
Total Complaints
26 filings
Crashes Reported
0 reports
Source
NHTSA ODI
Federal complaints database
At or below the fleet median complaint volume.
| Component | Count |
|---|---|
| VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM:HEATER CORE | 8 |
| SUSPENSION | 2 |
| ENGINE AND ENGINE COOLING:COOLING SYSTEM | 2 |
| SERVICE BRAKES, HYDRAULIC:FOUNDATION COMPONENTS:DISC | 1 |
| SERVICE BRAKES, HYDRAULIC:FOUNDATION COMPONENTS:DISC:ROTOR | 1 |
| SEATS:FRONT ASSEMBLY:HEAD RESTRAINT | 1 |
| STEERING | 1 |
| STRUCTURE | 1 |
| FUEL SYSTEM, GASOLINE | 1 |
| SEAT BELTS:FRONT:RETRACTOR | 1 |
| ENGINE AND ENGINE COOLING:ENGINE | 1 |
| VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM | 1 |
| TIRES | 1 |
| VISIBILITY:REARVIEW MIRRORS/DEVICES:INTERIOR | 1 |
| SUSPENSION:REAR | 1 |
"TAKATA RECALL" I FOUND THE MOST RECENT RECALL ON THE PAGE, HTTPS://DRIVING-TESTS.ORG/VIN-DECODER/ WHEN I TRY TO KNOW MORE ABOUT VIN NUMBER WAS. I SEARCHED IN GOOGLE SEARCH. AND THAT WHY I FOUND THIS INFORMATION. THANS A LOT FOR YOUR HELP. THE VEHICLE WAS IN MOTION.
Mileage: 208,640
"TAKATA RECALL" I FOUND THE MOST RECENT RECALL ON THE PAGE, HTTPS://DRIVING-TESTS.ORG/VIN-DECODER/ WHEN I TRY TO KNOW MORE ABOUT VIN NUMBER WAS. I SEARCHED IN GOOGLE SEARCH. AND THAT WHY I FOUND THIS INFORMATION. THANS A LOT FOR YOUR HELP. THE VEHICLE WAS IN MOTION.
Mileage: 208,640
"TAKATA RECALL" I FOUND THE MOST RECENT RECALL ON THE PAGE, HTTPS://DRIVING-TESTS.ORG/VIN-DECODER/ WHEN I TRY TO KNOW MORE ABOUT VIN NUMBER WAS. I SEARCHED IN GOOGLE SEARCH. AND THAT WHY I FOUND THIS INFORMATION. THANS A LOT FOR YOUR HELP. THE VEHICLE WAS IN MOTION.
Mileage: 208,640
I OWN A MITSUBISHI DIAMANTE, 1999. I NOTICED FUMES COVERING THE PASSENGER SIDE WINDSHIELD. IN THE WINTER TIME THE PROBLEM IS WORSE AND IT COVERS BOTH PASSENGER SIDE AND DRIVER'S SIDE CREATING VERY DANGEROUS DRIVING CONDITIONS. *TR
REAR END UNSTABLE. VEHICLE BACKEND SWERVES AND FISHTAILS ON WET OR ICY SURFACES. REPAIR SHOP STATES BACK END IS FROZEN AND UNABLE TO ALIGN REAR TIRES CAUSING VEHICLE TO SWERVE WHEN DRIVEN ON WET OR ICY SURFACES. MISALIGNMENT OF REAR RESULTS IN NEW TIRES HAVING TO BE PURCHASED APPROXIMATELY EVERY 2-3 MONTHS. *TR
Mileage: 210,500
TL*THE CONTACT OWNS 1999 MITSUBISHI DIAMANTE. THE CONTACT STATED THAT WHILE TRAVELING AT VARIOUS SPEEDS THE REAR VIEW MIRROR WOULD SHAKE; AND WAS NOT SECURELY ATTACHED TO THE WINDSHIELD. THE VEHICLE WAS TAKEN TO AN AUTHORIZED DEALER WHO STATED THAT THE REAR VIEW MIRROR WAS ATTACHED PROPERLY. ON A SEPARATE OCCASION THE REARVIEW MIRROR BROKE AND DETACHED FROM THE WINDSHIELD. THE REAR VIEW MIRROR WAS REPLACED BY AN AUTHORIZED DEALER. THE CONTACT DETECTED THE PROBLEM SINCE THE PURCHASE DATE OF THE VEHICLE. THE FAILURE MILEAGE WAS 200. THE VIN WAS UNAVAILABLE.
1999 MITSUBISHI DIAMANTE. CONSUMER STATES THAT THREAD PATTERNS ON TIRES ON VEHICLE ARE ASYMMETRIC. *TGW THE CONSUMER STATED THE TIRES DIDN'T HAVE ANY TREAD WEAR, OR OTHER RATINGS ON THEM. THE CONSUMER WAS TOLD THE TIRES WERE MOUNTED CORRECTLY. UPDATED 04/14/10. *JB
Mileage: 102,590
SMELL OF ANTIFREEZE INSIDE CAR, WINDOWS FOGGED UP MAKING IT VERY DIFFICULT TO DRIVE. MECHANIC SAYS IS LIKELY HEATER CORE FAILURE, $700 TO FIX. *NM
Mileage: 86,000
HEATER CORE ON 1999 DIAMANTE LEAKED IN PASSENGER COMPARTMENT. WINDOWS FOGGED UP AND ELECTRICAL COMPONETS WERE LEAKED ON. *JB
THE WINDOWS FOG UP SO BAD THAT IT BECOMES HARD TO SEE. THE VENTS SPEW OUT THE PUNGENT SMELL OF ANTI-FREEZE. I HAVE NOTICED ON MORE THAN A FEW OCCASIONS THAT PUFFS OF VAPOR SHOOT OUT FROM UNDER THE PASSENGER SIDE DASH AND VENTS. I KNOW THAT ANTI-FREEZE IS POISONOUS TO HUMANS AND DON'T THINK THAT ITS SAFE FOR ME TO BE DRIVING THE VEHICLE WHEN I HAVE TO BREATH IN THE VAPORS. *NM
Mileage: 60,000
MY HEATER CORE IS FAULTY, MY DEFOGGER WONT WORK, AND IT IS EMITTING SOME TERRIBLE FUMES IN THE CAR, ALSO ANTI FREEZE IS LEAKING ON THE FRONT PASSENGER FLOOR. *NM
Mileage: 145,000
1999 DIAMANTE ENGINE BLEW THREE WEEKS AFTER PURCHASE. *TS *JB
Mileage: 90,000
I OWN A 1999 MITSUBISHI DIAMANTE WITH 87K MILES ON THE ODOMETER. MY WIFE WAS DRIVING THE VEHICLE LAST WEEK AND NOTICED THAT THE WINDOWS OF THE CAR STARTED TO FOG UP. THE FOGGING BECAME SO THICK THAT SHE HAD TO PULL OVER (BLINDLY) AND FRANTICALLY WIPE THE WINDOW CLEAN IN ORDER TO SEE OUT OF THE CAR. SHE HAD TO CANCEL HER TRIP SHORT BECAUSE THE PROBLEM KEPT RECURRING THE CAR ALSO STARTED TO SMELL LIKE ANTI-FREEZE, WHICH, ACCORDING TO MY WIFE, CONTINUED TO GET STRONGER AS SHE DROVE IT HOME. I CALLED THE LOCAL MITSUBISHI DEALERSHIP AND WAS TOLD BY THE PERSON IN THE SERVICE DEPARTMENT THAT THIS IS A COMMON PROBLEM FOR THIS CAR AND THAT BY NOT REPAIRING IT IMMEDIATELY IT CAN CAUSE THE ECU TO FAIL (THE CAR COMPUTER) WHICH COULD CAUSE A LOSS OF CONTROL IF THIS OCCURS AT SPEED. MITSUBISHI IS AWARE OF THE PROBLEM BUT HAS NOT TAKEN ACTION TO ISSUE A RECALL OF THE DEFECTIVE PART (THE GASKETS THAT ATTACH THE HEATER CORE TO THE COOLING SYSTEM). I AM LOGGING THIS COMPLAINT ONLY BECAUSE I HAVE
Mileage: 86,900
WINDOWS FOGGED SO BADLY I COULD NOT SEE, SYRUPY SMELL IN VEHICLE, LOSS OF COOLANT IN RESERVIOIR, PUDDLE OF COOLANT ON PASSENGER SIDE FLOOR. *AK
I STARTED TO NOTICE AN ODD SMELL IN THE VEHICLE AND NOTICED A LACK OF COOLANT IN THE RESERVOIR TANK. AFTER A FEW WEEKS I REALIZED THERE WAS COOLANT ACCUMULATING ON THE PASSENGER SIDE FLOORWELL. MY VEHICLE IS AT 53,500 MILES AND WAS DIAGNOSED BY THE DEALER AS HAVING A "HEATER CORE FAILURE." THE ESTIMATE THEY GAVE IS $1,300 TO REPAIR. I CANNOT AFFORD IT SO IT LOOKS LIKE MY VEHICLE WILL BE GARAGED UNTIL A RECALL IS ISSUED. *AK
Mileage: 52,500
I'M EXPERIENCING A SYRUPY SMELL INSIDE THE CAR WHEN THE HEAT IS ON. PER THE VARIOUS RESEARCH I HAVE PERFORMED, THIS IS A SIGN OF A FAILING HEATER CORE. THIS IS A KNOWN FAILURE BY MITS PER TSB 627114 THAT WAS ISSUED. ADDITIONALLY, ON >2000 MODEL YEAR DIAMANTES, MITS BEGAN PUTTING THE VEHICLE?S COMPUTER (ECU) IN A PLASTIC BAG SO THAT WHEN THE HEATER CORE DOES FAIL, IT DOES NOT RUIN THE ECU AND CREATE ADDITIONAL SAFETY RISKS. THIS IS JUST ANOTHER SIGN THAT MITS IS AWARE OF THE ISSUE AND RATHER THAN DESIGNING OUT THE PROBLEM, THEY PUT A BANDAGE OVER A POTENTIAL EFFECTED AREA. UNFORTUNATELY MY VEHICLE IS 1999 WHICH DOES NOT HAVE THE PLASTIC BAG AND THUS I AM EXPOSED TO THE ADDITIONAL RISKS. THE ESTIMATE I RECEIVED TO FIX THIS WAS $1100. I AM FILING THIS COMPLAINT TO ASCERTAIN THAT THIS IS A VERY COMMON PROBLEM IN DIAMANTES AND MITS SHOULD BE AWARE OF 3 MAIN RISKS: (1) THE DEFECT EXPOSES CUSTOMERS TO AN UNACCEPTABLE LEVEL OF TOXIC ETHYLENE GLYCOL WHICH SHOULD NOT EXCEED 10-25PPM LEVELS (2) T
Mileage: 78,000
PROBLEMS WITH VEHICLE'S SEAT BELT EQUIPMENT. *MR THE SEAT BELT DID NOT RETRACT. (FRONT PASSENGER SEAT) *SC *JB
MITSUBISHI DIAMANTE 1999: WINDSHIELD STARTED TO GET FOGGY, INSIDE CABIN SMELLED ON COOLANT AND OCCASIONAL PUFFS OF "SMOKE" EVAPORATED OUT OF THE WENTS. THIS PRESENTED VERY DANGEROUS DRIVING CONDITIONS. COULD NOT DRIVE CAR FOR 2 MONTHS. DEALERSHIP DIAGNOSED AND WANTED $1000 FOR THE REPAIR OF THE HEATER CORE. DUE TO THE LACK OF MONEY, I DID IT MYSELF WITH PROPER INSTRUCTIONS. PROBLEM WAS IN BAD O-RINGS THAT CAUSED COOLANT TO LEAK INTO CABIN AND OVER IMPORTANT COMPUTER MODULE. HALF-YEAR LATER, NO SMELL, NO WAPOR, NO FOG IN THE CABIN. PICTURES CAN BE SEEN AT HTTP://WWW.JOLDIC.COM/GALLERY/HEATER-CORE-ADVENTURE. *AK
Mileage: 70,000
HEATER CORE ISSUE WITH MITSUBISHI DIAMANTE 1999 SUMMARY: NOTICE CONSISTENT AND VERY NOTICIABLE FOUL ODOR WHEN CAR IS SHUTOFF. CAN SMELL INSIDE THE VEHICLE AS WELL. SOME FOGGING OF FRONT WINDSHIELD. HAVE HAD THIS PROBLEM IDENTIFIED AS CONSISTENT WITH HEATER CORE'S ISSUES BY OTHER DIAMANTE OWNERS WHO HAVE HAD THEIR CAR SERVICED AT A MITSUBISHI DEALER. HAVE NOT REPLACED ANYTHING YET BECAUSE THE PARTS AND LABOR QUOTES HAVE BEEN ANYWHERE FROM $600-$1000. CAR HAS 56,000 MILES ON IT, BUT HAVE NOTICED PROBLEM SINCE BUYING THE VEHICLE LAST YEAR WITH 36,000 MILES. TRIED ADDING STOP LEAK TO THE GAS WITH NO RESULTS. *LA
HEATER CORE ISSUE WITH MITSUBISHI DIAMANTE 1999 SUMMARY: NOTICE CONSISTENT AND VERY NOTICIABLE FOUL ODOR WHEN CAR IS SHUTOFF. CAN SMELL INSIDE THE VEHICLE AS WELL. SOME FOGGING OF FRONT WINDSHIELD. HAVE HAD THIS PROBLEM IDENTIFIED AS CONSISTENT WITH HEATER CORE'S ISSUES BY OTHER DIAMANTE OWNERS WHO HAVE HAD THEIR CAR SERVICED AT A MITSUBISHI DEALER. HAVE NOT REPLACED ANYTHING YET BECAUSE THE PARTS AND LABOR QUOTES HAVE BEEN ANYWHERE FROM $600-$1000. CAR HAS 56,000 MILES ON IT, BUT HAVE NOTICED PROBLEM SINCE BUYING THE VEHICLE LAST YEAR WITH 36,000 MILES. TRIED ADDING STOP LEAK TO THE GAS WITH NO RESULTS. *LA
Data as of 2025. Sources: NHTSA Office of Defects Investigation (ODI) complaints database, NHTSA recall campaign API, NHTSA NCAP crash-test ratings, and NHTSA FARS for fatality cross-reference.
Read our methodology — how this data is sourced, computed, and verified.