AI Damage2001 Mitsubishi Diamante: common problems
Owners of the 2001 Mitsubishi Diamante filed 78 complaints with NHTSA, most often about visibility and engine and cooling. Details by component below, with sources.
Key figures
- Owner complaints
- 78
What fails most often
- 1 Visibility 72% of all complaints
- 2 Engine and cooling 18% of all complaints
- 3 Powertrain 5% of all complaints
- 4 Service brakes 5% of all complaints
- 5 Suspension 4% of all complaints
- 6 Tires 4% of all complaints
- 7 Equipment 1% of all complaints
- 8 Seat belts 1% of all complaints
- Visibility: 56 complaints (72% of all).
- Engine and cooling: 14 complaints (18% of all).
- Powertrain: 4 complaints (5% of all).
- Service brakes: 4 complaints (5% of all).
- Suspension: 3 complaints (4% of all).
Engines and transmissions
US-market versions per EPA. On the right: how many NHTSA complaints name this engine or transmission type.
- 3.5 L · petrol · 6 cyl
- automatic, 4-speed
Drive: FWD
Symptoms owners describe
How many of the 78 NHTSA complaints mention each symptom (automatic count from complaint text; one complaint can mention several).
Components owners complain about
| Component | Owner complaints | involving a crash | Technical service bulletins (TSB) |
|---|---|---|---|
| Visibility | 56 | 0 | 0 |
| Engine and cooling | 14 | 0 | 0 |
| Powertrain | 4 | 0 | 0 |
| Service brakes | 4 | 0 | 0 |
| Suspension | 3 | 0 | 0 |
| Tires | 3 | 0 | 0 |
| Equipment | 1 | 0 | 0 |
| Seat belts | 1 | 0 | 0 |
| Structure | 1 | 0 | 0 |
| Vehicle speed control | 1 | 0 | 0 |
| Wheels | 1 | 0 | 0 |
| Other | 1 | 0 | 0 |
What owners report
Short excerpts of NHTSA complaints in the original wording. These are owner statements not verified by NHTSA; personal data removed.
My heater core went out at about 100k miles; my abs light stays on (due to a speed sensor fail), which renders the whole anti-lock system useless; and now my antenna mast is broken. All of these problems are pricey to fix, and most diamante users I have found experience at least a few of these conflicts.
Windows are fogging up do t a faulty heater core. I really don't mind repairing the car seeing that it has 120k on it.. I purchased the car brand new and this will be the 3rd heater core!!! What's going on!
Mitsubishi diamante infamous heater core problem antifreeze leaks into interior of car. Horrible sickening anti freeze smell, happens on an abundance of mitsubishi cars.
Heater core is causing the windows to fog up, the car to smell like antifreeze and may be damaging the ecu. There are hundreds of posts online about people having this problem over and over with this car. It is clearly a manufacturers defect and customers are left paying thousands of dollars fo the repair.
2001 mitsubishi diamante. We have had it about six months. I have had it in to a very reputable service station and have come up empty on the following problem. The car has new tires, this occurred before and after they were installed.
Upon further investigation, I noticed anti-freeze/engine coolant leaking from the heater core down onto floor mats, climate control intake, electrical wiring inside dashboard, and more importantly automatic transmission computer. This is a significant safety and health issue and needs to be addressed immediately.
I am feeling a constant vibration on the front end of car, and I just replaced the front tires. I checked to see if the weights are still on the rim and they are. All of a sudden I started to hear a very loud noise and when I pushed the gas pedal the vibration would get worse.
But in feb, the burning odor became stronger especially when I turn on the heater. Now, the front interior windows become fogs up right away whenever I turn on the heater or just driving. The odor is getting me sick, and the windshield is so fogged that I need to constantly wipe it just to see out.
When owners complained
NHTSA complaints by filing year. The peak shows at what age the problems show up most.
Comparison
By complaint count this model year ranks 4,151 of 36,656 model years in the NHTSA data (top 11% most complained about).
On average one model year of the Diamante has 42 complaints (12 years in the data). This year has 78, above average.
What to check before buying
- Visibility. Wipers, mirrors, defrosters, cracked glass.
- Engine and cooling. Radiator and fan after a frontal hit, coolant level and condition, overheating.
- Powertrain. Shift quality under load, harsh shifts, transmission codes, CV joints.
- Service brakes. Pedal feel, ABS operation, leaks, discs and hoses.
Other years of this model
Questions and answers
What are the most common problems with the 2001 Mitsubishi Diamante?
Owner complaints to NHTSA most often mention: visibility, engine and cooling, powertrain. Total complaints: 78. The most frequent symptoms in complaint texts: A/C or heater (72%), windows, sunroof (46%), smoke, burning smell, fire (12%).
How many service bulletins (TSB) were issued for the 2001 Mitsubishi Diamante?
NHTSA lists 0 manufacturer service bulletins for this year. A bulletin tells dealers how to diagnose or fix a known issue; it is not a recall.
Should I buy a 2001 Mitsubishi Diamante from a US auction?
Owner complaints describe defects, not crash damage. Before bidding, check the components listed above and review the lot photos: VinWind builds a report of visible and hidden damage by VIN.
Other 2001 models
Read also
Sources: public NHTSA data (USA): service bulletins and owner complaints; YouTube: links to videos credited to their authors. Complaints are owner statements not verified by NHTSA, and describe defects rather than crash damage. Data updated 2026-11-05.