Engine Cooling System Problems of Mitsubishi Diamante - part 1

I have a 2003 Mitsubishi Diamante LS with 71677 miles on it all of the sudden my husband (the primary driver) tells me that every time he gets out of the car he feels light headed and nauseous. Days later the front windshield started fogging up while driving and after turning the car off (whether it is warm or cold outside) I googled why would this happen and have spoken with a few mechanics and they are telling me that it is the heater core going out, and that the reason why my husband is getting light headed and nauseous is because there is anti-freeze coming into the interior of the car which is very detrimental to your health. I have read a ton of complaints on different websites and they all say the same thing. I contacted Mitsubishi corporate today and spoke with a kim in customer service and explained to her what was going on and asked why Mitsubishi has not done anything about this. First because of the health implications, secondly because of the safety issue of the windshield fogging up while you're driving to where you can't see and thirdly that from reading the complaints, the heater core is right above the computer in the car so if the heater core is leaking antifreeze, it could fry the computer and cause a possible crash if the car were to stop suddenly. She said that "seeing that I hadn't had the car into a dealership in the last year that there is nothing they can do about it". I told her that it just started and what was I suppose to do, look into my crystal ball and know a year ahead of time that the heater core was going to go out. This is ludicrous! ! ! Mitsubishi knows that this is a serious issue and are not doing one thing to fix it (by issuing a recall) where do we Diamante owners go to get some help? do we need to file a class action lawsuit as that seems like the only way a fire is going to get lit under them (corporations tend to act if it means losing tons of money) the car can't be driven and I'm still paying on it. Help!.

See all problems of the 2003 Mitsubishi Diamante 🔎.

Mitsubishi Diamante 2002 has faulty o-rings and is widely publicized to cause major heater core problems and anti-freeze leakage.

See all problems of the 2002 Mitsubishi Diamante 🔎.

I own a mistubishi Diamante, 1999. I noticed fumes covering the passenger side windshield. In the winter time the problem is worse and it covers both passenger side and driver's side creating very dangerous driving conditions.

See all problems of the 1999 Mitsubishi Diamante 🔎.

Anti-freeze leak on carpet passenger side near firewall fogged up windows check engine light comes on and off due to the leak the ecu started working awful.

It happened out of no where. No signs or warnings to help prevent this problem. The heater core leaks uncontrollably. It's a long labor job and happens pretty early in the cars life spans. The parts are cheap to replace but the consequences are drastic.

I bought a 2002 Mitsubishi Diamante LS 10/3/07. He had 53,000 miles on it. It now has about 75,000 miles. My problem is the same as hundreds of owner of this car. Heater core issues. I recently had the heater core gaskets replaced as I was told that the heater core was ok, still had to pay for labor. It is now leaking again. This is a very common problem and seems that mitsubushi is unwilling to do anything about this. The heater core is right above the computer that runs the car. When the heater core goes bad, its leaks on the computer. What kind of sense does that make? my engine light is constantly on and I have seen the tcl light come on as well. I have searched the internet and all 3 of these problems are very common. I want to know if there is anything that can be done about this or if mitsubushi has addressed the problem and I am not aware of. I cannot afford to fix the car or get a new. Please help!.

At approx 60k (I am the original owner) the car began to emit mist from the vents. The first incident was a near overheating event which caused me to check the coolant. After topping off the level the car operated normally for a few months and then repeated the behavior. The tcl went off, the check engine light came on, the mist got heavier, and the car is a danger to both myself as an operator and others on the highway because the fog from the antifreeze damages visibility. The floor mat on the passenger side has also gathered moisture from the apparent leak. This scenario is well documented by others and demands a recall.

I own a 2003 Mitsubishi Diamante, around 60k miles I started noticing a sweet smell from the vents and a constant fog when the heat or air was turned on in the car. After taking my car to the mechanic I was told that my heater core was busted. My car also sdriving in "safe mode" meaning I can only run in second gear which is burning a tank of gas every three day, I love 10 miles from work. My car flashed in neutral will in drive. After researching my problems I've notice well over 1000 posted via internet from other Mitsubishi Diamante owners having the same issue. Its hard to believe this vehicle has not be recalled. There are great risks of inhaling anti freeze which is seeping into the car through the floor boards and vents. I have an asthmatic child who has been driving in the car until the problem was brought to my attention. This leak may also make the computer system in the vehicle go out. Something needs to be done before an accident is caused or a life is taken.

My transmission relay went out due to a leak heater core. The core has been leaking for some time and has fogged my windows so bad I could not see at times, having to pull over and wipe off the film. This is a serious problem with these cars.

I have 2003 Mitsubishi Diamante. My "check engine" light came on, so I took it in for service, and my heater core was leaking on my computer. . . Now it's going to cost me around 3,500 dollars. . . . This is a very flawed design. There should be a recall on this item.

I found postings of the same heater core issue. Windshield fog and the awful syrup smell of anitfreeze. There needs to be a recall as you can clearly see the history of complaints dating back to 1995 or earlier. Please look into this urgent matter.

Heater core leaking into passenger side of car, releasing coolant vapor into car cabin.

I own a 2003 Diamante Mitsubishi. The problem started with a check engine light coming on, fogging the window with a fowl toxic smell then the car would not hardly move out gear. I was told that the car's heater core leaked onto the computer which caused the transmission relay to short out do to the computer failing. The computer was still under warranty at 78,000 miles but I still had to pay for the new computer system because I was told that it was the heater core that caused the computer to fail. This is such a poor design! the computer should have been protected in such a case. . . Funny thing it is now that I have had to replace a heater core, a computer and a transmission relay at a cut wrenching cost of $3,675. 58. I wrote a letter to the president of north America Mitsubishi that the heater core should be a recall but to no avail. I have all maintenance records on the Diamante so that was not what caused this heater failure. I do have the computer that was replaced. It is now April and the check engine light has come back on. . . Now what? aj.

Heater core failure caused failure of power control module. Total repair bill > $2,500. Mitsubishi is fully aware of the problem and neglects to even inform customers that there are steps that can be taken to remedy the problem before a costly breakdown. Defective pcm causes severe drivable problems.

This is a Mitsubishi Diamante 2003 ES. I'm experiencing a sweet smell of anti-freeze inside the car as soon as I turn on heating. Anti-freeze contains ethylene glycon and the fumes are highly toxic. Fixing the heater core will cost $1300. I am filing this complaint to ascertain that this is a very very common problem in Mitsubishi Diamante and Mitsubishi motors should be aware of three main risk associated with this: (1) the defect exposes customers to unusual level of toxic ethylene glycol which should not exceed 10-25 ppm levels (consult msds for ethylene glycol) (2) the leak can affect the car's microprocessor and poses a severe hazard for drivers. (3) faulty heater core makes the visibility difficult due to fogging of windshield thus putting the driver at greater risk. I will eventually fix the problem by spending $1300 if Mitsubishi refuses to issue a recall. Right now I am trying some radiator anti-leak to delay the costly repair. But I want NHTSA to be aware of the hazards that has been ignored by the manufacturer.

Maple syrup smell from air vents then car started to overheat heatercore failure, antifreeze in floorboards on windshield and coming through air vents. A new heatercore installed very costly had to do work myself because warranty expired. Had to shampoo carpets and buy new floormats because the anitfreeze ruined them. After reading many complaints you would think that a recall would be made. Just because no deaths the consumer should suffer. What about the money that it took to make the repair. That was money taken from my family that we use to feed us and have shelter. Come on you have to authority to do something so why don't you.

Leakage of antifreeze ( engine coolant) into the passenger compartment of vehicle. The coolant smell was apparent within the car.

Heater leakage from faulty seals, complained of headache for 3 weeks as soon as leak was discovered and fixed headaches have been gone.

At about 70,000 miles I started to see a very fine mist-like smoke coming from the dash while driving. There were no warning lamps illuminated on the dash. So after the temp gauge started to go up and I could also smell anti-freeze. I checked the radiator area and could find no leak but when I checked the coolant it was low. I topped off the coolant and a couple of months later it did the same thing. I then added stop-leak and the coolant level seems to be staying but I can still smell the anti-freeze and the windows fog up. I understand there is an issue with gaskets on the heater core. I am worried the coolant leaked into my vehicle in the area of the ecm. To me, this is a serious safety issue and Mitsubishi should be correcting this problem because it is very common from what I have read on-line.

2003 Mitsubishi Diamante with 65000 miles. Noticed fog coming out of vents around the radio. It smelled like anti-freeze and created a fog on my windows that was bad enough to render the car undriveable. I was also getting an error message of p-1751. This refers to a problem with the transmission relay control. I took the car to a transmission shop and after diagnosing for two days, the mechanic told me that he had discovered a leaking heater coil that may or may not have damaged the pcm. Worst case scenario, $1600. It will at least cost $500, best case scenario. I uncovered numerous complaints from Diamante owners with models from a wide range of years who were experiencing the same problems. This is criminal negligence and I personally request an investigation to research how mistubishi has been getting away with this, for so long. The same exact problems are occurring on a frequent basis.

My wife and I noticed antifreeze odor coming in through vents. When our windows would fog, our defroster wouldn't work. Then our passenger side floor was soaked with antifreeze. We took the car to the dealer, our heater core was leaking. Cost was $1300 to repair. Mitsubishi should be held responsible!! too many complaints.

See all problems of the 2000 Mitsubishi Diamante 🔎.

This is the second time I am complaining about the same problem. The end of June 2006 I drove to work and reached down to pick some stuff up off the passenger side floor mat. It ended up being soaked. At first I thought some water had come in because the past few days our area had torrential rains. When I got home the next day I took up the floor mat to dry it out and notice all the liquid under it was greenish yellow. In my mind I went crazy because the same thing had happened to me a year and 2 weeks earlier. Once again the heater core became faulty and poured the engine coolant into the passenger spaces. Wonderful, since my wife was 8 months pregnant, great for her to be breathing those chemicals. I have to say I was fortunate that it didn't leak on any of the computer components, like has happened to others, especially while I was driving. Would have definitely caused a safety issue. It just blows my mind that I have had to pay for the same service twice in about a year, on a car that has less than 80,000 miles on it. I really hope the NHTSA looks into making this a recall issue, because it is just happening to too many consumers. Just imagine all those people who don't even know they can file a complaint. Yes, I know there were no deaths or injuries in my case, but when the coolant leaks on the computer brain of the car, it could become a real issue if driving on the highway or navigating crowded streets in town. The power stearing or antilock brakes would shut down if the computer crashed from getting wet.

Heater core leaks into car steams up windows and leaks on the computer and changes the transmission shifting.

Recently the windows keep fogging up in my 2002 Mitsubishi Diamante. I have found through complaints with you and other internet sites that this is a common complaint and very expensive to remedy. Is there nothing being done by nhsta to make the manufacture fix this dangerous problem? every day it gets worse. So far I have not noticed a coolant leak, but from what I have read, it is forthcoming is a very dangerous problem that needs to be solved!!.

Heater core defective and leaked coolant underdash on to transmission ecm and neutral safety switch. Because of this very common manufacture defect I had to have my heater core, transmission ecm, neutral safety switch replace. And my transmission rebuild, none of which were warranted by the manufacture and were not cheap.

I purchased a used 2003 Mitsubishi Diamante from bankston Dodge in 2007. It was clean and ran well. There was an unusual odor inside, but smelled as if it could have been what the dealership used to clean the inside. It turned out to be anti-freeze. The vehicle had a heater core leak prior to our purchase. Recently the gas gauge has stopped working.

2003 Mitsubishi Diamante coolant leak inside the car. Steam fogging the windows and strong chemical odor leaving residue on windows. Quoted $1000 to repair, they say it needs a new heater core. It may not be the heater core, but just seals. I have bypassed the heater hoses and fortunately live in a warm area.

My car is making me sick!! I noticed a smell of anti-freeze coming out of the climate control vents. 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. Where is manufacturer's recall.

See all problems of the 2001 Mitsubishi Diamante 🔎.

Our 2002 Mitsubishis Diamante vr-x has been misting from the heater core for a few years. The problem is bad gaskets (o-rings) that join the heater core with the lines for the heater hoses. The heater core is installed right over the pcm unit. If it leaks badly enough, the pcm and transmission relay will be destroyed. It (heater core) failed shortly after the warranty expired and when we went to Mitsubishi dealer, they refused to fix it. They quoted us $1400. 00 for repairs. On the internet, there are hundreds of complaints for the same problem, but no one has gotten any satisfaction from Mitsubishi. I put some radiator stop-leak in and this seemed to help somewhat, but it is starting to mist again with anti-freeze in the passenger compartment. This is a toxin and is dangerous to inhale and will jeopardize my family's health.

Noticed a smell of antifreeze comming out of the climate control vents. Upon further investigation, I noticed antifreeze/engine coolant leaking from the heater core down onto floor matts, 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. Where is manufacturer's recall.

The fumes of antifreeze fogged up the windows severely, reducing visibility of the driver. It was raining one night and my windows all of a sudden got foggy. I turned on the defroster, which made my windows even foggier. The poor visibility caused me to run off the road into the grassy median. I was out of town when this occurred. In doing research on this problem I found that it was common all Diamantes (92 -2001). In many cases, the driver is not aware that this is a severe problem. The antifreeze will started leaking on the passenger?s side area. Causing more strong smell of toxic antifreeze. I believe this to be a safety issue.

I started to notice an odd smell in the vehicle and noticed a lack of coolant in the reservoir tank. After a few weeks I realized there was coolant accumulating on the passenger side floorwell. My vehicle is at 53,500 miles and was diagnosed by the dealer as having a "heater core failure. " the estimate they gave is $1,300 to repair. I cannot afford it so it looks like my vehicle will be garaged until a recall is issued.

My car is making me sick. I purchased my car in Aug. 2001 and began to notice a smell in the car and fume closely resembling that of radiator coolant. The car was assesed by a Mitsubishi district manager and service personnel from my dealer and deemed to be sound. In the mean time I have suffered with runny eyes and intermittent paralysis in the right side of my face dependent on the amount of time spent in the car. I have contacted Mitsubishi numerous times about this and received no assistance. In November 2004 I noticed an increase in this smell and fogging problems of the interior windows. I took the car to the dealer telling them that I believed the problem was with the heater core. I ascertained this information through internet research dealing with Mitsubishi Diamante defects and problems. The car was returned to me with this problem more severe than when I took it in for repair. Any help or ideas that you can offer would be greatlly appreciated.

My heater core went on my automobile. The car is a 2001 Mitsubishi Diamante which has 50,000 miles on it. The problem started when the car had 45,000 miles on it, but I didn't know it was the heater core until later on. The dealer had the car for 2-l/2 days for a job that was 6. 9 hours. I was told that the box that the core was in was either broken or couldn't be shut, but then they were able to close it, fix it I hope. I was told by another mechanic that it could have been the o-ring and that they had a car the same year with the same problem, possible recall. The dealer did a shabby job in replacing my dash board, I have 3 screws that I found on the floor, my glove compartment has a screw missing, none of which I have in my possession fits the missing screw hole. When I picked up the car, the steering column came apart in my hands and so they took it back in to fix. Do they not check things after they complete a job, like are all the screws back in place. I will never buy another Mitsubishi and never advise anyone to buy one either. I was told that a heater core shouldn't break at only 50,000 miles and the car is only 3 years old.

Car smells like coolant. Windows won't clear up while im driving. Very foggy. Dealer said I need a new heater core at 43,000 miles.