Problems · NHTSA complaints
1997 Mitsubishi Diamante problems
Owners filed 34 complaints about the 1997 Mitsubishi Diamante with NHTSA between Aug 1997 and Jul 2008. The most-cited component is service brakes, hydraulic (13).
Complaints
34
Filed with NHTSA
Crashes
2
Reported by owners
Fires
1
Reported by owners
Injuries
1
People reported injured
Deaths
0
Reported to NHTSA
Complaints by component
One complaint can cite several components
- Service brakes, hydraulic13
- Power train10
- Engine and engine cooling4
- Visibility3
- Fuel system, gasoline3
- Tires2
- Seat belts2
- Electrical system2
- Parking brake2
- Vehicle speed control2
- Structure1
- Steering1
- Service brakes, air1
- Latches/locks/linkages1
Complaints are unverified owner reports to NHTSA and are not normalized for sales volume. One complaint can cite several components.
Data from NHTSA Complaints API · synced Oct 30, 2026NHTSA vehicle page
When complaints were filed
Does it get worse with age? Complaints per calendar year filed
2
11
5
6
3
1
0
0
2
0
1
3
View as table
| Model year | Complaints filed per calendar year |
|---|---|
| 1997 | 2 |
| 1998 | 11 |
| 1999 | 5 |
| 2000 | 6 |
| 2001 | 3 |
| 2002 | 1 |
| 2003 | 0 |
| 2004 | 0 |
| 2005 | 2 |
| 2006 | 0 |
| 2007 | 1 |
| 2008 | 3 |
Mileage at failure isn’t a structured field in NHTSA complaint data, so we don’t chart it. Some owners mention it in their reports below.
Top problems in owners’ words
Verbatim from NHTSA complaints, newest first
Service brakes, hydraulic
13 reports1 crash
“I PURCHASED THIS VEHICLE 2 MONTHS AGO AND HAVE MADE 5 TRIPS BACK TO THE DEALER DUE TO BRAKES, TIRES & ENGINE TAPPING AND NOW THE TRANSMISSION SEEMS TO BE SLIPPING. *AK (DOT NUMBER: N/A TIRESIZE: P21560R16)”
Power train
10 reports1 crash
“SAFETY - TRANSMISSION: AT 9,500 MILES MY CAR STARTED LURCHING WHEN STEPPING ON THE GAS FROM A STOP. IT SUPPOSEDLY WAS REPAIRED BUT HAS CONTINUED TO BE PROBLEM AND EACH TIME I BRING IT IN FOR SERVICE THE DEALER CAN NOT RECREATE THE PROBLEM. SINCE I HAD NOT HEARD THAT THIS HAS BEEN ON GOING PROBLEM WITH THIS MODEL, I THOUGHT IT MUST BE SOMETHING THAT I HAD DONE. UPON REVIEWING THE INFORMATION OF NHSTA, I REALIZE THAT THE DEALERS AND MITSUBISHI ARE DELIBERATELY HIDING THIS PROBLEM. SAFETY - FUEL TANK: MY FUEL TANK BEGAN LEAKING AT 59,560 MILES AND WHEN THE DEALER REMOVED IT HAD 3 STRESS WHOLES. THE TANK HAD TO BE SENT OUT FOR WELDING. OF COURSE, I HAD TO PAY FOR THE REPAIR EVEN THOUGH I SPOKE DIRECTLY TO THE MITSUBISHI COMPLAINT DEPARTMENT. SINCE IT WAS NOT A RECALL ITEM, MITSUBISHI OR THE DEALER WILL NOT PAY FOR THE REPAIR. THE DANGEROUS FUEL LEAK IS ANOTHER ONGOING HIDDEN PROBLEM. ALTERNATOR PULLEY: HAS BEEN MAKING NOISE FROM THE BEGINNING AND I HAVE COMPLAINED EACH SERVICE. NOW, I DISCOVER THROUGH NHTSA THAT ALTERNATOR PULLEY IS A KNOWN DESIGN FLAW. MITSUBISHI AND THEIR DEALERS MUST BE HELD ACCOUNTABLE.*AK”
Engine and engine cooling
4 reports
“THERE IS A MAJOR PROBLEM WITH THE MITSUBISHI DIAMANTE HEATER CORE GOING OUT. MINE WENT OUT A FEW DAYS AGO AND WAS INFORMED BY MITSUBISHI IT WILL COST ME 965 TO REPLACE. EVEN THOUGH THERE ARE HUNDREDS OF MITSUBISHI DIAMANTE OWNERS COMPLAINING ABOUT THIS PROBLEM INCLUDING WITH PEOPLE THAT HAVE AS LOW AS 30-45K ON THEIR VEHICLE. PLEASE LOOK AT THIS FORUM WHICH SHOW MANY MITSUBISHI OWNERS COMPLAINING ABOUT THEIR VEHICLE.. HTTP://WWW.DIAMANTEOWNERS.COM/FORUM/LOFIVERSION/INDEX.PHP?T3615-0.HTML PLEASE HELP ME AND HELP THESE POOR OWNERS. RECALL THIS MAJOR ERROR MISTUBISHI KNOWS ABOUT BUT REFUSES TO DO ANYTHING ABOUT IT AND KEEP SILENT. THIS ALSO CAN CAUSE DEATH BECAUSE WHEN THE HEATER CORE FAILS IT LEAKS AND CAUSES A BAD ODOR OF ANTIFREEZE. YOU WOULDN'T WANT YOUR KIDS BREATHING ON THAT WOULD YOU. ON THE WEBSITE I HAVE PROVIDED YOU IT WILL SHOW A CASE IN WHICH A PERSON WENT INTO RESPIRATORY FAILURE DO TO INHALING ANTI FREEZE.. MANY OF THESE OWNERS TILL THIS DAY FACE A DANGER BECAUSE THEY HAVE NO CHOICE BUT TO DRIVE THESE VEHICLES AS IT IS THERE ONLY MEANS OF TRANSPORTATION AND MANY CANNOT AFFORD TO FIX THIS EXPENSIVE PROBLEM (COSTING AS MUCH AS 1,300). WE BEG OF ALL THE…”
Visibility
3 reports
“TL*THE CONTACT OWNS A 1997 MITSUBISHI DIAMANTE. THE CONTACT STATED THAT THE RADIATOR LEAKED DUE TO THE HEATER CORE. THE RADIATOR LEAKED ONTO THE CARPET WHEN THE HEAT WAS ACTIVATED. THE CONTACT STATED THAT HE AND HIS FAMILY HAVE INHALED TOXIC FUMES FROM THE RADIATOR LEAKING ONTO THE CARPET AND THEY ARE CONCERNED OF FUTURE HEALTH RISKS. IN ORDER TO REPAIR THE LEAK, THE ENTIRE DASHBOARD HAD TO BE REMOVED. THE VIN WAS UNAVAILABLE. THE CURRENT MILEAGE WAS 113,000 AND FAILURE MILEAGE WAS 112,000.”
Fuel system, gasoline
3 reports1 fire
“DT: CONSUMER HAD 1997 MITSUBISHI DIAMANTE. CONSUMER TOOK VEHICLE TO DEALER,. VEHICLE HAD A GAS LEAK, DEALER COULD NOT FIND HOLE IN GAS TANK, CONSUMER REPLACED GAS TANK, ABOUT 8 MONTHS AFTER GAS TANK WAS REPLACED THE VEHICLE EXPLODED. *AK”
Tires
2 reports1 crash
“TL*THE CONTACT OWNS A 1997 MITSUBISHI DIAMANTE. THE VEHICLE HAS COOPER LIFELINER CLASSIC II TIRES, SIZE 115/60/15. WHILE DRIVING APPROXIMATELY 70 MPH, THE REAR DRIVER'S SIDE TIRE SPONTANEOUSLY BLEW OUT. THE CONTACT LOST CONTROL OF THE VEHICLE AND CRASHED. THE VEHICLE WAS COMPLETELY DESTROYED AND A POLICE REPORT WAS FILED. PRIOR TO THE CRASH, SHE NOTICED THAT THE TIRE PRESSURE WAS NORMAL AND THAT THE TREAD DEPTH WAS 8/32. AFTER INSPECTING THE TIRE, AN OFFICER CONCLUDED THAT THE TREAD WAS DEFECTIVE BECAUSE CHUNKS OF THE TREAD WERE MISSING AND WIRES WERE HANGING OUT OF THE TIRES. THE CONTACT HAS PICTURES OF THE FAILED COMPONENT. THE TIRE FAILURE MILEAGE WAS 13,000. THE VEHICLE FAILURE MILEAGE WAS 151,000. UPDATED 09/10/08 *BF UPDATED 09/16/08. *JB”
Data from NHTSA Complaints API (owner reports, unverified) · synced Oct 30, 2026
Complaints are unverified owner reports to NHTSA and are not normalized for sales volume. One complaint can cite several components.