Mitsubishi Diamante owners have reported 4 unknown or other related problems since 1996. Table 1 shows the 1 most common unknown or other problems. The number one most common problem is related to the vehicle's unknown or other (4 problems). For details of each of the problem category, use the links in the table.
| Problem Category | Number of Problems |
|---|---|
| Unknown Or Other problems |
The main issue seems to be a manufacturing defect in the wave/cushion spring located in the transmission. Mitsubishi has designed the wave spring as a fragile two coil piece which has been known to repeatedly break causing catastrophic failure in the transmission. This in turn poses a threat on the driver and passengers. When this wave spring breaks, actual pieces of the wave spring make it through Mitsubishis also faulty transmission filter and lodge themselves in the pump gear, causing the gear to actually break. After the pump gear has been broken inside the transmission, all forward and reverse gears immediately stop function and in most instances the vehicle shuts off. This could result in potential harm or even death of the driver and/or passenger as the vehicle loses all moving power which can cause an accident with other vehicles on the road. Mitsubishi has recently created an updated version of the wave spring without issuing a recall, which now is a one piece instead of the coil setup and has a less chance of breaking. This update was discovered after they I had my vehicle in a transmission shop with a hefty bill to pay ($3,700) even though it was Mitsubishis fault for engineering a faulty part in their transmission. All one person would need to find out about this issue is search the internet with the transmission code (f4a51) and this issue is well documented, even researched by transmission digest (a specialty magazine). Not only is this a large inconvenience, it is also a hazard to ones life. Mitsubishi should recall all vehicles which contain the f4a51 automatic transmission to perform the wave spring and filter update or reimburse those, like myself, who have already had it done at my cost.
We have a five-year-old Mitsubishi Diamante. For the last week, my husband, scott has smelled a sweet smell in his car and had a problem with the windows fogging. Tuesday morning he started losing forward power when driving to work on i480. He noticed that his dashboard transmission lights were acting funny so he called our Mitsubishi dealer. The service people asked if he had noticed that the windows were fogging or if he smelled any anti-freeze coming from the heater. Scott was astonished that the sweet smell was antifreeze. The service advisor said that most likely it's because that Diamante has experienced heater cores leaking into the passenger compartment and dripping onto the transmission computer. This is why he was losing power while driving on i480. One of my concerns is what health problems can come from driving in an enclosed environment while the heating system is mixing antifreeze fluid in the air that my husband is breathing while commuting to work. Later on that same Tuesday, the service advisor called him and said that their service manager spoke directly with the regional Mitsubishi service representative and he said that the heater core was too far out of warranty to be covered based on 36,000 mile warranty. The transmission computer, while covered up to 84,000 miles, would also not be covered because the failure was due to antifreeze dripping on the computer causing it to fail.
I own a preowned 1998 mistubishi Diamante LS. When the climate control, particularly the heater is engaged, the smell of anti-freeze becomes quite apparent. Dealer claimed 2 years ago when I bought it that it was the smell of the chemicals used to clean the car during "make-ready. " ethylen glycol fumes are toxic and this is a reoccuring defect in this model car from posts I have seen on various websites. I was later told that to fix this problem will cost close to $1000 since the car is out of warranty. Mitsubish issued a TSB addressing this problem, obviously they are aware of it. In addition, the windshield is covered with a film that cannot be washed off from this leak. A recall should be issued for this problem, I am not the first person to file this complaint on your website. Thank you.
After being stopped a couple of minutes because of a passing train, when proceeding, the car would not move more than, probably, 5 mph. Noticed a smell coming in, like oil burning. Didn't see no smoke coming out of hood. Check engine light came on. Parked car and got out to see black smoke coming from behind the car. Turned off engine and tried to turn on to move car, it wouldn't turn on again. Had car towed to dealer. It happened right before entering freeway, thank god.