really awful
Crashes / Fires:
0 / 0
Injuries / Deaths:
4 / 0
Average Mileage:
51,206 miles

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« Read the previous 20 complaints

problem #22

Feb 152006

Diamante 6-cyl

  • Automatic transmission
  • 43,310 miles
Strong coolant (anti-freeze) smell in car. Windows fogged up and could not see and puffs of smoke coming from vents. Dealer informed me heater core needed replacing. Also stated that although it was known issue with vehicle Mitsubishi would not take care of cost. Mitsubishi has even issued a tech pub on parts needed to repair this problem because they were experiencing a shortage. It took four days to get a heater core for my vehicle due to a critical shortage of heater cores.

- Pflugerville, TX, USA

problem #21

Feb 212006

Diamante 6-cyl

  • Automatic transmission
  • 82,401 miles
Noticed bad odor in the vehicle followed by the windows fogging up and the heater not working a few days later. Repair shop stated that the heater core needs to be replaced. This is unusual for cars that are only a few years old and have low mileage. Repair would be around $1000. I have the 2002 Diamante and this part was very hard to find. Even the dealership had to order it. Can anything be done to help with this cost. Just a struggling man trying to provide for a family in a honest way. Please help!!

- Eclectic, AL, USA

problem #20

Feb 222006

Diamante 6-cyl

  • Automatic transmission
  • 62,000 miles
Excessive fogging of interior windows and failure to clear up have resulting in very unsafe driving conditions. My wife was driving with our children and just missed getting hit by a tractor trailer the other day. In addition the smell of antifreeze is disgusting! brought the car to the dealer and spent nearly $600 to repair "O rings". does not seem right to have as many complaints on this issue without having the manufacturer properly address the issue. Someone is going to get killed or severely injured sooner or later. I guess we should wait for that to happen before we hear from NHTSA and mitsuibishi.

- Pittsford, NY, USA

problem #19

Nov 302002

Diamante 6-cyl

  • Automatic transmission
  • 1 miles
The first time my 5 year old son drove in this car, he vomitted. Everytime he rides in it he becomes nauseous. The car's windshield fogs up and a sickly sweet smell comes out of the vents. The windshield is covered in a permanent haze. We noticed these symptoms but had not given it a second thought since the car was new and had no reason to suspect major problems. The car was recently in the shop for 1 week, when we picked it up we really noticed the sweet smell and alerted the shop. After inspection the shop diagnozed it as a heater core problem, a leak that is vaporizing and condensating on the windshields. The anti-freeze fumes are noxious, and after some research we have found that Mitsubishi has been aware of the problem and has even issued 2 tsb about the problem. Mitsubishi fails to correct the problem by fixing the car. Because of the noxious nature of the fumes, the number of complaints on record, Mitsubishi should be forced to recall these cars and to fix the problem. If NHTSA refuses to help all of us who have been screwed by another large corporation, why am I paying my taxes, so that you can protect corporate interests like all other federal agencies? the incident is everyday.

- Chatham, IL, USA

problem #18

Dec 032005

Diamante 6-cyl

  • Automatic transmission
  • 35,000 miles
Heater core hoses leaked by 34K miles - seeping anti freeze into passenger side carpet, smelling of syrup, and fogging up windows when they needed to be defogged. Also, tires were noisy from first drive. At 36.5K miles they are very bad, vibrating entire car and making extreme road noise.

- Raleigh, NC, USA

problem #17

Jan 122005

Diamante 6-cyl

  • Automatic transmission
  • 587,520 miles
'02 Mitsubishi Diamante; heater core failure; 2nd owner eff. 2/05; bought from same dealer that leased to 1 person; found many other owners suffering same issue on google to site: www.diamanteowners.com/forum/index.php"S=918C701E5465C87381ccae0aa22C20A3&showtopic=3615 I have been quoted $1200 by 2 dealers and $900 by a mechanic/independent. The dealer that leased the car to '1st owner' and sold it to me at end of lease told me that they are working on two Diamantes per week for heater core replacement! why is there no recall yet??" this leak - per brad/sale and service dealer states that if I fail to fix immediately - 10 hours of labor - radiator coolant will leak into passenger foot well/flood and the leakage goes over my computer that runs the car! 2 repairs a week is unacceptable!!! please help!!! I have a toddler and teenager riding daily with me smelling the radiator fluid that steams inside windshield (cannot use heater). This fogging occurs even when heater not in use (although much milder in condensation). Bought car in mint condition -used- at same dealership that issued lease/all scheduled maintenance performed. I cannot afford this obvious defect that needs full 'recall' status - please help! P.S. personally, I have wanted this car for 6 years - to have this issue, and obviously just before a recall will / "** to be made is so terribly stressful and disappointing. Updated 07/17/2012

- Carlsbad, CA, USA

problem #16

Dec 192005

Diamante 6-cyl

  • Automatic transmission
  • miles
Heater core failure - windshield fogged up severely, and turning on defroster made problem worse as gaseous ethylene glycol was pumped directly onto interior windshield. Very hazardous driving conditions, as well as air quality in car cabin was extremely pungent w/eg fumes.

- Simpsonville, SC, USA

problem #15

Jan 062006

Diamante 6-cyl

  • Automatic transmission
  • 50,070 miles
Could not clear the inside of the windshield. Smell like rotten eggs when I turn on the heater. The check engine light came on. The lights indicator on both the N and D were flashing. The automatic transmission shifting was difficult. Dealer's mechanic found that the automatic transmission relay had been damaged by coolant leaking onto the ECU from the heater core. Coolant was also found to have leaked under the passenger side carpeting. Replaced the heater core and the relay to a tune of $1,500 bill. Car has 50,000 miles.dh.

- San Jose, CA, USA

problem #14

Nov 032005

Diamante 6-cyl

  • Automatic transmission
  • 29,000 miles
The contact stated while driving the windows would constantly be foggy. The vehicle was smoking under the dashboard. Also, coolant leaked inside the vehicle through the dashboard. The contact took the vehicle to a dealership to have the vehicle checked. They discovered the problem to be the heater core, it needed to be replaced. The manufacturer was contacted. No repairs were made.

- Hauppuage, NY, USA

problem #13

Nov 202005

Diamante 6-cyl

  • Automatic transmission
  • 97,572 miles
Heater core leaking and fogging up windows. Inhaling of radiator fluid fumes is noxious. Can not keep window clean, it's greasy, and can't see to drive without wiping off film. Passenger side carpet is wet from radiator fluid and I'm afraid smell will not go away.

- Geneva, IL, USA

problem #12

Nov 112005

Diamante 6-cyl

  • Automatic transmission
  • miles
The contact states there is a leak coming from the heater core. This causes anti-freeze to come inside the vehicle. The anti-freeze is obstructing his vision and he is breathing anti-freeze. The vehicle has not been to a dealership.

- Overland Park, KS, USA

problem #11

Oct 312005

Diamante 6-cyl

  • Automatic transmission
  • 68,000 miles
The vehicle is a 2002 Mitsubishi Diamante ls. The windows in the vehicle have been constantly foggy in a dry environment. When wiping windows down, I noticed that the condensation was oily. I have also noticed a syrup smell in the vehicle. The defroster has not been working properly, so I investigated online to find out if it was a common failure. What I found out was that the syrup smell and oily condensation was most likely due to a leaky heater core. I took the vehicle to a local mechanic who found that the O-ring seals for the heater core were failing. They pressured tested the core to be sure it was not failing also. The old parts are not available. The defroster was not related and only sparked my investigation into the oily condensation.

- Rio Rancho, NM, USA

problem #10

Oct 142005

Diamante 6-cyl

  • Automatic transmission
  • 68,500 miles
Fog and mist on the inside of the windshield. Coolant levels dropped and refills were required, followed by a problem in the automatic transmission shifting and finally a check engine light warning. Mechanic found that the automatic transmission relay had been damaged by coolant leaking onto the ECU from the heater core. Coolant was also found to have leaked under the passenger side carpeting.

- Arlington, TX, USA

problem #9

Aug 012005

Diamante 6-cyl

  • Automatic transmission
  • 71,000 miles
The heater core has developed a leak that allows anti-freeze to enter and collect on the inside floor of the passenger compartment. This moisture inside the vehicle makes it impossible to clear the windshield with the defroster, making for a rather dangerous experience. This is on a 2002 Mitsubishi Diamante with fairly low miles. I've owned a large number of vehicles in my like and this is the first time a heater core has ever failed.

- Eldridge, IA, USA

problem #8

Jul 312005

Diamante 6-cyl

  • Automatic transmission
  • miles
Leaking gasket/heater core allowing toxic fumes to be emitted into the passenger compartment in excess of a year. Caused a film to form on windshield and the smell of anti-freeze in the passenger compartment. Quotes to repair exceed $1000.

- Spencer, IN, USA

problem #7

Apr 252005

Diamante 6-cyl

  • Automatic transmission
  • 35,000 miles
I purchased 2002 mitusbishi Diamante ls with 35000 miles from the Mitsubishi dealer in san bernardino, California. After driving off I noticed a smell of maple syrup. I also noticed that my eyes burned and itched when the heater was on. This was likely due to the white cloud that came from the heater duct. It was also causing cloudy windows that made safe navigation impossible. The carpet I starting to puddle with antifreeze on the passenger side. I took it in for a routine oil change, and had the dealer mechanic check the smell. They informed me that the heater core was leaking, and would need to be replaced. Their quote was $1060 and was not covered by my bumper to bumper warranty. This is a health hazard and the leaky heater core could cause massive damage to the computer that controls the engine. They will not correct the problem even thoug it wa a problem at drive off.

- San Bernardino, CA, USA

problem #6

Nov 212004

Diamante 6-cyl

  • Automatic transmission
  • 46,000 miles
Failure in the heater coil with less than 50000 miles antifreeze leakig into passenger compartment and fogging window.

- Atlantic Highlands, NJ, USA

problem #5

Apr 012005


  • miles
2002 mitshubishi diamonte auto heater core fails and leaks; windows remain fogged for a long period. Vents and ac first failed 5/2004. An authorized deader repaired symtom w/O a root cause. By 4/1/2005, defroster/defogger became progressively worse until visibility was unsafe and the vents emitted an odorous smell. Original dealer discontinued service and an authorized dealer initially refuse to cover the repair. Nothing was done or diagnosed after 6 hours, reporting the vents worked ok. I re-opened a case by contacting the mfg who acknowledged growing safety reports with the heater core. The dealer was given 2-3 working days or review. Meanwhile.

- Ln, CA, USA

problem #4

Feb 162005


  • miles
Windows fogged up and would not clear up. There was a kind of sweet burning smell. Did research on the internet and found that is was the heatercore leaking antifreeze and all the symtoms listed on site matched my car. Checked the passenger side and found puddle of antifreeze soaked in the carpet. Also the antifreeze in the radiator was very low. My wife drives this car and she is 8 months pregnant! she had been unknowingly inhaling the antifreeze vapors since the leakage. Took it to the dealership and it cost me $690 to fix (3/10/05). I had to wait 3 days before the parts came in and 1 day to have it fixed. This car is only a 2002 and has 52,000 miles! what a coincedence that the warranty expired. I am currently driving the car since my wife is pregnant and the car still smells like antifreeze! I have to drive it with the windows down since the smell of antifreeze vapors are still strong. I am very concerned about the affects of breathing the antifreeze vapors.

- Olathe, KS, USA

problem #3

Dec 262004

Diamante 6-cyl

  • Manual transmission
  • 30,000 miles
Heater core has failed. Anti-freeze leaks and, as the result, syrup-like smell is everywhere inside the car! windows fog up. Possible damages are not to be ignored!. if the problem isn't taken care of, it can undoubtedly lead to long term health problems due to anti freeze fumes, as well as electrical damages to the computer.

- Spokane, WA, USA

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