DIAMANTE

Mitsubishi Diamante Problems

What actually breaks on the Mitsubishi Diamante — 349 owner complaints filed with NHTSA across 1992–2004, sorted by model year and by system, with what owners wrote in their own words.

NHTSA owner complaints · 349 reports · 161 builds · Updated Aug 5, 2026
Quick answer

Owners have filed 349 complaints on the Mitsubishi Diamante, covering 1992–2004. The system named most often is Visibility (129 reports). Worst years by volume: 2002, 2001, 2003; cleanest: 2004, 1995, 1994. 21 reports describe a crash, 2 a fire. On average the car was 4.2 years old when the problem happened.

What breaks on Mitsubishi Diamante

Grouped by the system owners named — percentages are shares of all 349 Diamante complaints. Open any row for the full reports in owners' own words.

Visibility 37% 129 Read
1992 Mitsubishi Diamante

While driving front passenger side mirror caught on fire. Manufacturer was contacted

2003 Mitsubishi Diamante

Vehicle experienced a problem with the heater coil. Anti-freeze was getting into vent, and the vapors fogged up the windows, interrupting the visibility. Owner contacted the manufacturer, who refused assistance because the vehicle was out of warranty

2003 Mitsubishi Diamante

About a month and a half ago I noticed an odd smell in my car. Not realizing what it was I continued to drive my car. Then a week ago my car started to over heat because I didn't have any coolant. I also noticed a film on my windows. I have a mat under the car and haven't noticed anything leaking on to the ground. My…

Engine And Engine Cooling 20% 70 Read
2002 Mitsubishi Diamante

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…

2003 Mitsubishi Diamante

2003 mitsubishi diamante coolant leak inside the car. Steam fogging the windows and strong chemical odor leaving residue on windows. Quoted $1000 to repair, they say it needs a new heater core. It may not be the heater core, but just seals. I have bypassed the heater hoses and fortunately live in a warm area

2003 Mitsubishi Diamante

Maple syrup smell from air vents then car started to overheat heatercore failure, antifreeze in floorboards on windshield and coming through air vents. A new heatercore installed very costly had to do work myself because warranty expired. Had to shampoo carpets and buy new floormats because the anitfreeze ruined them.…

Service Brakes 11% 37 Read
2002 Mitsubishi Diamante

When stepping on the brake pedal while making a right turn at 25 mph vehicle lost brake power. Then, the brakes made a squeaking noise. When this occurred front left tire hit a curb, and the axle and rim broke. Consumer had to engage the emergency brakes to stop the vehicle

1997 Mitsubishi Diamante

While driving at 15 mph ABS brakes failed vehicle did not stop and continued to move hitting vehicle in front. Also, transmission failure, resulting in extreme shifts

2003 Mitsubishi Diamante

When the brakes were applied, the vehicle vibrated uncontrollably. The driver was able to maintain control of the vehicle and drove it to a repair shop for inspection. The mechanic informed the consumer that the rotors and pads may need to be replaced. *jb the consumer found nothing apparently wrong before the parts…

Power Train 7% 23 Read
2004 Mitsubishi Diamante

The diamante has an odd issue where the vehicle will not shift gears correctly which an extremely dangerous issue for drivers. The information board shows the transaction rapidly switching from neutral to drive excessively. I have had multiple mechanic shops look into this issue from transmission specialists, to…

2002 Mitsubishi Diamante

Transmission retaining rings brake and jam gears. Car stopped in intersection had to be pushed off road and towed to shop replaced transmission. Was told by repair person that this is something that mitsubishi knew was happening for the last 2 years

2002 Mitsubishi Diamante

I have had the transmission replaced including the torque converter $5000. I am going on my second power antenna $300. The most recent called for a heater core replacement $1050

Air Bags 5% 19 Read
2003 Mitsubishi Diamante

Air bag did not deploy in 55 mph direct front end collision

2000 Mitsubishi Diamante

Vehicle involved in a head on collision at 30 mph, vehicle that impacted my vehicle was travelling at 25 mph. The entire front of car including bumper was destroyed by the 55 mph impact. Neither airbag deployed. The driver airbag appears to have begun to deploy, but did not

2000 Mitsubishi Diamante

Driver rear ended another vehicle at 30 to 35mph, and neither driver's side nor passenger's side airbags deployed. Dealer has not seen vehicle

Electrical System 4% 14 Read
1993 Mitsubishi Diamante

Wiring harness shorted out, causing fire

2003 Mitsubishi Diamante

Car doors are locking by themselves, the alarm for keys being left in the ignition no longer sounds, the automatic unlock when keys left in the ignition no longer works, and the headlights do not turn off when the car is turned off and door opened. Have been stranded several times due to keys locked in the car, and a…

2002 Mitsubishi Diamante

Headlights turn off for a split second while driving down the highway. It does this when the AC system kicks in. Lights on the inside of the vehicle dim as well. This happens at both idle and high RPM. A volt meter shows a large voltage spike for a short period of time. The voltage regulator is not responding fast…

Suspension 4% 14 Read
2003 Mitsubishi Diamante

2003 diamante purchased in oct 2003. Vehicle vibrated "horribly" when brakes are applied. Vibration/loud highway tire noise. Both rear tires "cup". Also, rubbing sound r/f wheel area when turning. Despite seven (7) attempts at repair by dealer this condition persists. Ongoing condition. Manufacturing rep offers to put…

2003 Mitsubishi Diamante

When I apply the brakes, the car shakes and jerks uncontrollably. I have had work done on the rotors as well as the brakes. I have four new tires, but problem still occurs. I am afraid that one day while driving this car the brakes will fail and cause my family and I serious injury . This is a 2003 mitsubishi…

2003 Mitsubishi Diamante

Vehicle front end shifts back and forth when behind tractor trailers on highway. Situation is dangerous when tractor trailer pulls out in front of me. Not due to tailgating, since it is the worst when approximately 5 car lengths are between tractor trailer and me. Car is difficult to control due to shifting. Front end…

Seat Belts 2% 8 Read
1994 Mitsubishi Diamante

Was in an accident the drivers air bag didn't deploy and seat belt didn't restrain hit the front windshield. Tt

2001 Mitsubishi Diamante

Seat belt on drivers side of of 2001 mitsubishi, diamante has retracted back into the side column retractor mechenism and will not release back out. Took vehicle to a local service repair shop and they did not have an answer. The retractor is a sealed unit from the mfg. And can't be opened. It appears that the…

1998 Mitsubishi Diamante

Rear passenger side shoulder belt buckle could not be unlatched. This caused child to be locked in the seat belt and unable to move. Seat belt had to be cut near the waistline area to free the child. *ak

Diamante years to avoid — and the clean ones

Complaints per model year. More reports usually means more cars on the road as well as more trouble, so read the crash and fire columns alongside the count.

FIG.02·Mitsubishi Diamante complaints by model year
Model yearComplaintsTop systemCrashesFires
20041Power Train
200338Air Bags1
200289Electrical System3
200156Engine And Engine Cooling
200033Air Bags2
199916Engine And Engine Cooling
199819Engine And Engine Cooling,visibility,unknown Or Other1
199724Electrical System2
199510Air Bags3
199412Air Bags1
199321Air Bags81
199230Air Bags1
ROWS 12·SOURCE NHTSA owner complaints

The same model year, different builds

Every complaint carries the first 11 characters of the VIN — plant, year, body and engine. That is a production series, and complaints are spread across them very unevenly.

FIG.03·Mitsubishi Diamante complaints by production series
MeasureValue
Distinct production series161
Average complaints per series2.2
Worst single series8 complaints
Average age at failure4.2 years
ROWS 4·SOURCE NHTSA owner complaints + ForCar

A model average of 2.2 hides a worst series at 8. Enter a VIN above to see the numbers for that exact build instead of the model as a whole.

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How we count

Every figure here comes from complaints owners filed with NHTSA — 1,100,006 of them, covering 1,982 models built between 1981 and 2026.

A complaint is an unverified report: someone wrote down what happened to their car. It is not a confirmed defect and not a recall. What makes the volume useful is the pattern — when thousands of owners of the same build describe the same failure, that is a signal no marketing brochure will give you.

Two things we do that the source does not. First, we compute the age of the car at the moment of failure from the incident date and the model year. Second, we group complaints by the first 11 characters of the VIN — the production series — so a bad plant run does not disappear into a model-wide average.

Frequently asked questions

What are the worst years for the Diamante?

By complaint volume, 2002, 2001, 2003 drew the most owner reports. Bear in mind that popular years put more cars on the road, so check the crash and fire columns too.

Which Diamante years are the cleanest?

2004, 1995, 1994 have the fewest complaints on file. For recent years that can simply mean the cars are young.

How many complaints does the Mitsubishi Diamante have?

349 owner complaints filed with NHTSA, covering 1992–2004. Of those, 21 describe a crash and 2 a fire.

Are these complaints verified?

No. They are unverified reports from owners. NHTSA publishes them as filed and investigates only a fraction. The value is in the pattern, not in any single report.

Can I check complaints for one specific car?

Yes — enter its VIN above. We match the first 11 characters, which identify the plant, year, body and engine, so you get complaints on that exact production series rather than the whole model.

Owner complaints from NHTSA, published as filed and unverified. Age at failure computed by ForCar from incident date and model year; production series grouped by the first 11 VIN characters. Last updated Aug 2026. — ForCar Reviewed by , founder of ForCar.