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 electrical specialist and have had no positive results.
The worst 2004 Mitsubishi Diamante problems
Ranked by number of owner complaints. Mileage and cost come from what owners wrote.
- Transmission3
Problems by type
Tap a problem to see which part fails, at what mileage and in which other years.
- Transmission3
Recalls 1
Equipment: other: labels
- What is wrong
- 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.
- Risk
- This does not meet the 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. In addition, all current 2000-2004 nativa owners will also receive replacement air bag alert labels for the sun visors. This recall is expected to begin during march or april 2005. The notification to the nativa owners is expected to begin during april or may 2005. Owners should contact mitsubishi caribbean at 1‑787‑251‑8715.
Recall number 04V428000 · Recall details
Technical service bulletins for the 2004 Mitsubishi Diamante 29
Bulletins tell dealers how to fix known problems. A warranty extension means the manufacturer pays for that repair for longer.
- This is a Dealer Letter sent to dealers informing that Mitsubishi Technical Training has launched the 3rd...
- This Technical Service Bulletin reviews the regulations that require a label showing the reduction in load...
- This Technical Service Bulletin provides instructions and material safety data sheets for removal of...
- This is a Dealer Letter sent to dealers informing that Mitsubishi Technical Training has launched the 2nd...
- This Technical Service Bulletin was sent to dealers to explain the difference between normal dew...
- This is a service newsletter (Tech Talk) that was sent out to dealers.
- This is a Technical Service Bulletin sent to dealers
- This is a message sent to dealers, to inform them that an update for MEDIC will be available.
- This TSB contains troubleshooting steps for diagnosis of various customer complaints relating to the audio...
- This is an index of Tech Talk newsletter articles released in 2012.
2004 Mitsubishi Diamante fuel economy
Official EPA estimates in miles per gallon (MPGe for electric). Ranges cover trims that share the same engine.
| Engine | Drive | City | Highway | Combined |
|---|---|---|---|---|
| 3.5L 6‑cyl | FWD | 15 | 23 | 18 |
What 2004 Mitsubishi Diamante owners say
Most recent owner complaints, unedited.
Cpsc#i11b0131a. 2004 mitsubishi diamante. F4a51 automatic transmission failure. *ln the consumer stated she has concerns with the safety and reliability of mitsubishi and dodge vehicles and their owners that have the mitsubishi f4a51 automatic transmission in certain make/models. The main issues seemed to be a manufacturing defect in the wave/cushion spring located in the transmission designed the wave spring as a fragile two coil piece which has been known to repeatedly break causing catastrophic failure in the transmission. When the wave breaks, actual pieces of the wave spring make it through mitsubishi's also faulty transmission filter and lodge themselves in the pump gear,causing the hear to actually break. After the pump gear has been broken inside the transmission, all forward and reverse gears immediately stop functioning and in most instances the vehicle shuts off. The consumer stated she had the f4a51 automatic transmission in her vehicle, which had to be replaced.
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.
Compare the 2004 Mitsubishi Diamante
Other model years
Questions about the 2004 Mitsubishi Diamante
Is the 2004 Mitsubishi Diamante reliable?
Owners have filed 3 complaints about the 2004 Mitsubishi Diamante, fewer than a typical Diamante model year.
What is the 2004 Mitsubishi Diamante year score?
The 2004 Mitsubishi Diamante scores 95 out of 100 (good). The score compares it with the other model years of the Mitsubishi Diamante: 75 is a typical year, 50 means twice the usual complaints, and serious complaints and recalls lower it.
What is the most common problem with the 2004 Mitsubishi Diamante?
Transmission and drivetrain, with 3 complaints.
How many recalls does the 2004 Mitsubishi Diamante have?
1 recall, covering equipment.
What year does the Mitsubishi Diamante have bad transmission?
The Mitsubishi Diamante model years with the most transmission complaints are 1997 (10 complaints) and 2002 (10 complaints).
What gas mileage does the 2004 Mitsubishi Diamante get?
Official estimates for the 2004 Mitsubishi Diamante range from 18 mpg combined. The most efficient version (3.5L 6-cyl, FWD) gets 15 city and 23 highway.
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