If I lived in a warm climate, I would bypass the heater core before I kept spending $1,500 on replacements, and would even consider it in a colder climate and install an electric heater.
I have a 99 with 136,000 miles and have had many of the same problems I see here (no heater core), but fix them myself saving a lot of money.
2001 Diamante @ 90,000 miles, heater core issues. I was told that I needed to replace the heater core at the sum of $1200.00. When I picked up my car from dealership and reviewed the bill, I realized that they only changed the O rings and did not replace the heater core. I believed I was ripped off by the Mitsubishi dealership. If Anyone knows of a class action lawsuit, please let me know. I am contacting the Mitsubishi corporate headquarters.
I purchased a used '02 Mitsubishi Diamante VR-X in 2007 with 85,000 miles. It too has the same anti freeze smell / leaking heat core problem so many others have experienced. I encourage you to submit your complaint via the National Highway Traffic Safety Agency website at http://www-odi.nhtsa.dot.gov/ivoq/. Only by a sufficient volume of consumer complaints will the US government open an investigation with Mitsubishi, so speak up!
I fixed the heater core issue for now thru bypassing the heater core entirely with the coolant lines in the engine compartment. That is fine for the warmer months when I don't need the heat. I have purchased the heater core replacement o-rings, and will tackle this permanent fix in the fall.
Now I have a new issue - the ABS & TC lights flash on / off, and the ABS system kicks in intermittently when braking. Had a brake shop inspect all four brakes and said the pads / rotors were all fine. I see some discussion on the rear wheel ABS sensor as possible culprit. Plan to go to Auto Zone to see if they can read ABS codes. Last resort is going to Mitsubishi dealer. Might also sign up for one of the on line repair manuals to download additional detail on troubleshooting ABS, plus get the Mitsubishi technical bulletins issued on this subject.
Anyone out there have more info on this subject???
OH MY GODNESSSS. I just purchased my 02 Mitsbushi Diamante 6 months ago with 69K miles.. and now with 72K miles my passenger side has antifreeze leaking all over it (heater core).
Then I got in my car this morning, and while I was in Drive, it was flashing NEUTRAL and the car was acting like it was in neutral & drive. WEIRD. Huge transmission problem, and now it's in the shop for god knows how long.
As for the heater core problem, they told me it was going to be an OVER $1000 job, and they could not bypass it with my make/model.
If ANYONE has had their heatercore bypassed in the past, PLEASE let me know and email me at firstname.lastname@example.org within the next few days, so I don't waste $$ fixing it, because I'm just going to sell the car anyways.
Worst car EVER.
I recently began experiencing the same intermittant TLC/ABS warning light display as described above. I was trying to prep myself before taking it in for repair to avoid the dealer needing to go on a diagnostic fishing expedition when I came across this site. I now see that I am part of the 'Foggy Windshield' club. My repair for that was over $1200 and I was told by the dealer that the gasket failed between the heater core and the rest of the cooling system. The high cost was due to 'difficult access to re-attach the core and having multiple hours of shop time to clean the inside of the windshield defrost ducts to prevent re-fogging the windshield with coolant still in the duct. If that in not a description of terrible design, I don't know what is. I will continue to watch these postings to see if any effort for a recall starts.
I bought a 2002 Mitsubishi Diamante LS in August 2007. After about 3 weeks my heater core went out and stained my carpet. Smoke came out of my vents and my car overheated in about 3 seconds with no warning.
Then of course after I got that fixed, my transmission was doing the neutral thing in drive, and I took it to a shop; they replaced my transmission, which didn't do the trick, because it did the same thing a week later, I took it back and found out it was my heater core leaking on the relay. I was almost disgusted with the whole thing. It's now June 2008 and it's just all got fixed.
This is followup to my June 6th posting (02 Diamante VR-X) :
I signed up for online repair manual service (eautorepair.net $25 for 1 year). Smart move. It provided considerable detail on ABS system diagnostics and repair. With a multimeter, basic tools, and pair of car jack stands, I was able to confirm that the right rear wheel sensor was faulty (low AC voltage output). After much calling around, I found salvage yard that had a low mileage '02 Diamante in reasonable good condition and sold me the right right wheel hub with sensor for $150. The Mitsubishi dealer quoted over $400 for new sensor (labor not included), and no auto parts stores or on line companies carry it. Fingers crossed that it will fix the ABS flashing light problem when I install it this weekend.
No change on my heater core problem, since I bypassed it earlier this summer. No more anti freeze smell problem or window fogging for now. I purchased the replacement o-ring gaskets ($3.00) to fix the leakage, and have a procedure to install them without having to remove entire instrument panel. The reason for high cost +$1000 repair bill when you go to a repair shop, is that the whole instrument panel must be removed in order to replace the entire heater core unit. The leakage issue is due to faulty o-ring gaskets, not the heater core unit itself.
I own a 2002 Mitsubishi Diamante, and I have problems with this car since the first day I drove it off the lot.
My windows constantly fog up really bad, especially in the winter times, and my service engine light won't go off, along with the TCL light that comes on and goes off, along with my Anti lock brake light that also comes on and goes off all the time while I am driving.
This is the worst car I have ever purchased, and I will never buy another Mitsubishi again. I have had this car for 6 years now and I hate it. I should have purchased a Nissan Maxima. We should all get together and write to Mitsubishi about our cars, because we are all experiencing the same problems with them.
I own a 2002 Mitsubishi Diamante, and it is running hot. I have had the thermostat replaced as well as a sensor replaced, and it is still running hot, especially when I turn the air on.
I also had the brakes replaced, front and rear, less than a month ago, and they are still grinding.
If anyone knows what these issues are, please post a message.