Huge win for car owners! All TSBs to be made public. The Center for Auto Safety just made the NHTSA (US Government) make public the full text of all TSBs from now on. They are the same organization that has petitioned the NHTSA & filed lawsuits to protect car owners over exploding gas tanks & other major safety issues. Whenever you drive in your car, you are safer thanks in part to a lot of work over the years by this small but very effective consumer advocacy group.

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NHTSA — Visibility: Defroster/Defogger System: Windshield: Heater Core Problems

2003 Mitsubishi Diamante (Page 1 of 2)

3.3

definitely annoying
Crashes / Fires:
0 / 0
Injuries / Deaths:
0 / 0
Average Mileage:
40,837 miles

About These NHTSA Complaints:

This data is from the NHTSA — the US gov't agency tasked with vehicle safety. Complaints are spread across multiple & redundant categories, & are not organized by problem.

So how do you find out what problems are occurring? For this NHTSA complaint data, the only way is to read through the comments below. Any duplicates or errors? It's not us.

2003 Mitsubishi Diamante accessories - exterior problems

accessories - exterior problem

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2003 Mitsubishi Diamante Owner Comments (Page 1 of 2)

problem #24

Oct 012008

Diamante

  • 85,000 miles

A D V E R T I S E M E N T S

Heater core leakage causing smoke and antifreeze odor to come out of car vents and underneath dash board (passenger side). There is a risk of accident, personal injury, or death because use of A/C, heater, and defrost is not available when windshields and windows fog up.

- Orlando, FL, USA

problem #23

Mar 292008

Diamante 6-cyl

  • Automatic transmission
  • 84,900 miles
Driving along and windows started to fog up, and started smelling a odd odor. Found out my heater core was bad. Apparently cracked for no reason. Right now by-passed the heater core because Mitsubishi dealer quoted $1,800 to fix it. It appears to be a big problem with the Diamante's.

- Raleigh, NC, USA

problem #22

Mar 202008

Diamante 6-cyl

  • Automatic transmission
  • 20 miles
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.

- Alta Loma, CA, USA

problem #21

Sep 252005

Diamante

  • Automatic transmission
  • miles

A D V E R T I S E M E N T S

I bought an 2003 Mitsubishi Diamante in 2005. My wife and I noticed an occasionally "syrup" smell, but didn't think much of it. This week end (March 08)anti-freeze (coolant) began to come out of the vents in a mist. It even turned the bottom half of my front windshield green created a film on the windows which made it hard to see. I have a new born child that is now sick as well myself and my 2 1/2 year old. They have a doctors appointments tomorrow and I hope they are not sick from the car. Estimated cost to fix was about $1150.

- Chesapeake, VA, USA

problem #20

Nov 272007

Diamante 6-cyl

  • Automatic transmission
  • 67,000 miles
I own a 2003 Mitsubishi Diamante ls with 70,000. I purchased the car from the dealership brand new. In November 2007, there was a strong smell of antifreeze in the car. After some investigation, it was discovered there was a leak in the heating core, which was causing the antifreeze to leak out of the compartment and into the cabin of the car...needless to say, the car is undriveable because of the health risks associated with breathing antifreeze. Estimated repairs are around $1500. This is completely ridiculous!!!! I am outraged to see that so many 2003 Diamante owners are having the same problem. I believe an investigation needs to be conducted, and Mitsubishi motors should be held accountable for this!!!

- Warner Robins, GA, USA

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problem #19

Dec 192007

Diamante 6-cyl

  • 37,813 miles
37813 miles. Heater core leaking. Notice the sweet smell and now overheating occurs.

- Spring Valley, CA, USA

problem #18

Nov 132007

Diamante 6-cyl

  • Automatic transmission
  • 86,000 miles

A D V E R T I S E M E N T S

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.

- Orlando, FL, USA

problem #17

Feb 172007

Diamante

  • miles
Regular use. Failure causes an odor inside the vehicle and a film which inhibits visibility on the windshield.

- Portsmouth, NH, USA

problem #16

Oct 052005

Diamante 6-cyl

  • Automatic transmission
  • 33,000 miles
For the past two years our car has had a very pungent fowl smelling odor when the air conditioner or heater is engaged that has gotten progressively worse. I took the car for repairs prior to the termination of the warranty and was told (by the dealership) that they did not notice a smell, and there was no problem. Six moths ago the car began to run hot and I took the car to our neighborhood mechanic. Under pressure he noticed a small leak in the coolant piping and replaced a section of pipe ($150). I asked if this could be causing the odor (as mentioned earlier and he stated maybe, or it could be the heater core).within the past two weeks the 'check engine soon' light has come on and upon checking the message and inspection of my car I've been told the heater core needs to be replaced. My neighborhood mechanic was at a loss because told me it was very odd for the heater core to fail so early in a car. I've checked the internet and have come across hundreds of people in the same situation (with Mitsubishi's). I am very upset with the fact that the Mitsubishi dealer may have lied to me (when the car was under warranty). I asked for multiple items to be fixed (under warranty) and they refuted every request. The heater core will be replaced within two weeks.

- Voorhees, NJ, USA

problem #15

Apr 062007

Diamante 6-cyl

  • Automatic transmission
  • 63,125 miles
I noticed the smell of maple syrup about two weeks ago. Today, the inside windshield and side windows of the Diamante fogged up with a grease film that would not clear. I went to my local mobile 1 and had the coolant system flushed. When I drove off it was actually worse. It got to the point that I could not see. I have suffered severe headaches for the last two weeks as well as nausea. I immediately drove to my Mitsubishi dealer. After analysis, it was determined that the heater core went out. As well, an oil leak had formed and the timing belt was going bad. They said that coolant was leaking in the right passenger floor, I felt it and never once did it feel damp, and they needed to clean the carpet and replace the flux for $237. The cost to repair the heater core and oil leak, $1300. The timing belt repair is $700. Thank god I bought the extended warranty. All but the timing belt is covered with a $100 deductible. I only have 63,000 miles on this car. This is my fourth Mitsubishi and may possibly be my last, especially if my health is jeopardized.

- Richardson, TX, USA

problem #14

Nov 232005

Diamante 6-cyl

  • Automatic transmission
  • 60,000 miles

A D V E R T I S E M E N T S

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.

- Saratoga, CA, USA

problem #13

Mar 052007

Diamante 6-cyl

  • Automatic transmission
  • 20,000 miles
Car smells like coolant. Windows won't clear up while im driving. Very foggy. It happened when the heaterwas needed. The odor was making me nauseous and sick. Dealer said I needed a new heater core at 20,000 miles.

- Sesttle, WA, USA

problem #12

Oct 102006

Diamante 6-cyl

  • Automatic transmission
  • 62,500 miles
The car only has 63,000 miles. An antifreeze odor was noticed initially and began to intensify with time. When the defroster is running the windshield will fog up and the anti-freeze smell is so intense that it nauseates my wife and kids. I have also noticed that the carpet on the passenger side is damp. It appears that this is a very common problem with the Diamante due to a failure with the heater core and its connections.

- Perry, UT, USA

problem #11

Feb 072007

Diamante

  • miles
I noticed that the windshield was fogged, and the defroster would not clear the fog. Blamed it on the humid Florida weather until one evening I was driving home from work and all of my windows were fogged. Had to keep wiping the windows with my hand in order to see out the window. Took the car to to be checked, and it was the heater core. This car is too new for the heater core to have gone bad.

- New Smyrna Beach, FL, USA

problem #10

Feb 092007

Diamante 6-cyl

  • Automatic transmission
  • 35,800 miles
Heater core issue with Mitsubishi Diamante 2003 summary: Notice consistent and very noticeable foul odor when heater is on.. fogging of front windshield. Have had this problem identified as consistent with heater cores issues by other Diamante owners who have had their car serviced at a Mitsubishi dealer. Have not replaced anything yet because the parts and labor quotes have been anywhere from $600-$1000. Car has 36,000 miles on it.

- Santa Monica, CA, USA

problem #9

Nov 012006

Diamante 6-cyl

  • Automatic transmission
  • 65,000 miles
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.

- Raleigh, NC, USA

problem #8

Aug 222006

Diamante 6-cyl

  • Automatic transmission
  • 55,000 miles
2003 Mitsubishi Diamante ls 58,000 miles. I noticed a 'maple syrup' smell in the cabin when the air conditioner and heater were running. I took it to the dealership when I began having transmission problems as well. No transmission problems were found, but the dealer advised that the heater core needed to be replaced at a cost of over $1,000. They will not know for several days if the leaky heater core has affected the transmission or engine controls. The heater core was leaking potentially toxic coolant into my passenger compartment in the car. Dealer advised me that they expect every Diamante from 1997-2003 will need this due to a manufacturer's defect. Mitsubishi also released a service bulletin to all dealers regarding this problem. Mitsubishi should be forced to recall the vehicles, otherwise at least advise all of the owners of said vehicles that the units should be replaced in the maintenance schedule.

- Champaign, IL, USA

problem #7

Aug 032006

Diamante 6-cyl

  • Automatic transmission
  • 61,145 miles
Make : Mitsubishi model : Diamante ls year: 2003 just purchased car from dealer stating car in excellent mechanical condition. Upon delivery of car from transporter, got in the car knew immediately there was film on window and could smell coolant in the air. Turned car on, strong smell of coolant coming through vents with coolant leaking onto passenger floor. Texas auto group, the seller, refused to accept responsibility despite representing car in excellent mechanical condition. Took to a Mitsubishi repair service and had to have heater core replaced at a cost of $1167.92. This repair service 40 miles away and it took 7 days to complete. Had to have carpet and car detailed to get rid of coolant smell. Researched on internet and found out this is a problem that has been going on since 1998 with these heater cores with Mitsubishi very much aware of it, and obviously nothing has been done to change this problem. This car only has 61145 miles on it and there is no excuse for this irresponsibility or costs to the consumers of these cars, including property damage as well as health risks to the consumers as coolant is toxic to breath. Mitsubishi should be forced to do a recall and reimburse their customers as they have know of this problem and have done nothing about it. Upon researching more, have found that some folks have had to have it repaired more than once. There is now starting to show complaints of the 2003 models. Very unhappy consumer and feel taken advantage of and have now paid more for this car then it is worth. Hope this will help another unsuspecting customer of the Mitsubishi Diamantes.

- Port Townsend, WA, USA

problem #6

Jun 202005

Diamante

  • miles
I own a 2003 Mitsubishi Diamante vrx and have a bad heater core at 43,000 miles. I have read on this website www.diamanteowners.com/forum/index.php"showtopic=3615&St=60 that the heater core is located directly above the car's computer. This is extremely dangerous as leaking fluids onto the computer can cause the car to malfunction and cause an accident. Perhaps this should be a recall"

- Haverstraw, NY, USA

problem #5

May 032006

Diamante 6-cyl

  • Automatic transmission
  • 64,000 miles
Heater core leaking causing fumes in the passenger compartment and fogging of the windshield.

- Ocean Bluff, MA, USA

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