Most common 1999 Mitsubishi Diamante problems
Share of the 23 complaints; one complaint can involve more than one system. "~" is the median mileage when the problem started.
Mitsubishi Diamante complaints by model year
Best Diamante years: 1995, 1999, 1998. Years to avoid: 2002, 2001, 2003, 2000. Compare all years →
1999 Mitsubishi Diamante recalls (2)
Equipment › Other › Labels
Certain passenger vehicles fail to conform to the requirements of federal motor vehicle safety standard no. 208, 'occupant crash protection.' the bilingual english/spanish removable air bag warning labels affixed to the dash and to the sunvisor do not meet the size requirements of the standard.
Remedy: Mitsubishi caribbean will mail a customer notification letter containing a written description and a graphic of the bi-lingual dashboard air bag warning label.
Parking brake › Driveline › Hydraulic
Vehicle description: passenger vehicles. The head of the screw that holds the retaining clip for the parking brake shoe can become brittle and break off.
Remedy: Dealers will replace the retaining clip screw and in the process inspect the rear brake system of any possible related damage. Any related damage that May be found will also be repaired.
What 1999 Mitsubishi Diamante owners say
A/C & heater
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 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.
Suspension
"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.
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.
Brakes
"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.
Rotors warped at 14444 miles, dealer turned them under warranty. They got warped again at 18700 mile, but dealer refused to address the issue, citing driver's driving habits.
1999 Mitsubishi Diamante engines & fuel economy
| Engine | Transmission | Drive | MPG city / hwy / combined |
|---|---|---|---|
| 3.5L 6-cyl | 4-speed automatic | FWD | 16 / 22 / 18 |
EPA ratings. Class: Midsize car.
Frequently asked questions
Is the 1999 Mitsubishi Diamante a good car?
Based on 23 owner complaints filed with NHTSA, the 1999 Diamante rates better than average: 61% fewer complaints than a typical year of the Diamante at the same age. It is one of the best Diamante years by this measure. Complaint counts don't account for sales volume or individual maintenance, so have any used car inspected before buying.
What is the most common problem with the 1999 Mitsubishi Diamante?
The a/c & heater — 9 complaints, 39% of all complaints for this model year, most often about defroster/defogger/hvac system › heater core. Next are the suspension (3) and brakes (3).
How many recalls does the 1999 Mitsubishi Diamante have?
There are 2 recalls for the 1999 Mitsubishi Diamante, the most recent from September 1, 2004 (labels). Recall repairs are free at any authorized dealer — check whether yours has been done with the VIN recall check.
What are the best and worst years of the Mitsubishi Diamante?
The best years by complaints, compared at the same age, are 1995, 1999 and 1998. Years to avoid or approach with caution: 2002, 2001, 2003 and 2000. See the full Mitsubishi Diamante years comparison.
At what mileage do 1999 Mitsubishi Diamante problems happen?
The median mileage reported in complaints is about 87,000 miles; 0% of problems with a recorded mileage started before 50,000 miles.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.