10th Jul 2008, 19:57

Hot Running Diamante:

Assume you see temp gauge reading higher than normal, but not to point of getting check engine light. Assume coolant level is where it should be. Do you hear your electric cooling fans coming on when vehicle reaching these high temps? If not, then that is your problem, probably either faulty fan relay, blown fuse, or fan motor itself. If fans are working, check for coolant leaks. If no leaks, then it may that water pump is wearing out and not able to properly circulate coolant. At this point, you'd best take it to a good shop to have them diagnose your problem. Good luck.

11th Jul 2008, 14:33

Thank you for responding to my issues, I took it back to mits. and they diagnosed it to be a head gasket and gave me a price range of 1800 to 3500...

22nd Jul 2008, 12:42

I would like to see this procedure to install the O rings for the heater core without extensive labor, if its possible please post on here...Thanks.

23rd Jul 2008, 18:24

See below for a link to a site with a procedure to change out the heater core o-rings without disassembling the whole instrument panel. It is still labor intensive and should only be attempted if you have basic mechanical skills, tools and patience.

Having already bypassed the heater core for the summer to get rid of the anti freeze smell and window fogging, I intend to tackle this challenge in the fall. My fallback is to remove the instrument panel myself, but I hope to avoid that. Let us all know how it goes with your situation.

If you're having intermittent ABS / TCL light flashing, let me know, as I just solved this issue for under $200 (vs $600+ at dealer). Good luck!


26th Jul 2008, 12:01

I purchased a 2002 Diamante in Feb, 08. I have the same problems, my heater core is bad, my carpet will have to be replaced, the TCL light flashes on from time to time.

I am really in a mess because I can't afford to fix these things. I'm in my last year of nursing school, not having reliable transportation is the last thing I need. If someone can tell me where to go to get these things fixed at a reasonable price and done right, Please let me know.. In Richmond, VA.

29th Jul 2008, 18:26

I just had new rotors and pads put on my wife's 2001 Diamante with 50k, this is the second time they have been replaced. They can't keep the anti-lock light from coming on. It stays on all the time now before it was coming on occasionally. Does anyone have a suggestion how to get the light off.



31st Jul 2008, 19:30

To Richmon VA:

Wish I were closer to be able to assist you with your two VERY common problems on the Diamante. Since money is problem, best thing now is to take care of the antifreeze leak and smell. Have a friend/family member obtain parts to by pass your heater core by removing and then connecting together the heater core coolant lines on the firewall in the engine compartment. This will at least take care of the smell and any more leakage for now (you'll have to clean up the carpets best you can). Later when you have the money and/or you get too cold in the winter since you won't have heat anymore, you can take it into a shop to have the heater core gaskets replaced. Sorry but this expensive about $1000, unless you can befriend a mechanic and talk him into a deal. It takes about 6 hours total.

The ABS/TCL ight flashing is another common problem, and it is almost certainly due to a bad wheel speed sensor. Mine was the right rear sensor. Your brakes will function OK, but your ABS system may not be working. I found a 02 Diamante in junk yard that had rear wheel sensor in good shape. I replace my bad one with it and fixed the problem. Too find out which one you will need to have a shop hook up diagnostic code reader on the ABS system. Dealer or shop will charge you about $600 for this repair, due to sensor retailing for $400. The junk yard one cost me $150. Again if you can befriend a mechanic, you may be able to get this down a bit.

Good luck! Marco in Indy.

7th Aug 2008, 20:33

To Joe/Pittsburg:

Interesting idea about the coolant additive to plug up the leaking heater core seals. It may work in some cases, but not in others. Guess there is little to lose in trying it, but I know the true fix is to replace the heater core gaskets. Just the thought of the time and bloody nuckles required just to get to those little buggars makes me mad. I agree that Mitsubishi should recall the heater core issue, but that won't happen.

Your TCL / ABS light is most likely due to faulty wheel speed sensor - it affects both systems. Question is which one. If you're handy, have basic tools and multimeter, and willing to spend the $25 to subscribe to on-line shop manual service, you can diagnose system and confirm which wheel sensor it is. Retail cost for sensor (if you can find it) is over $400 - unreal! Check around at junk yards for late model Diamante. Not easy car to find, but if you do, see if they'll sell you the wheel hub w/sensor that you need. I paid $150 for mine, and went out in the yard with the guy to make sure he didn't destroy the sensor taking wheel hub off. Got it home, installed it, and it took care of problem.

Regarding, antenna mast, it too can be replaced fairly easily. Kits are available on line for $25. Typically problem is due to corrosion or a bent mast that will no longer extend/retract. If you hear motor running but mast not extending, then motor is fine and problem is faulty mast. Another common problem but easily and cheaply remedied.

Marco in Indy.

16th Aug 2008, 20:57

I have a 2000 Diamante LS. It recently started with the whole anti freeze leaking deal, but we have ordered the o-rings and are ready to replace. We figured that this wouldn't be too hard, since we had to take apart the whole dash to get to the radio serial number when the car died, and then we had no code. It was labor intensive, but worth it.

I have another question though. Sometimes when I go around curves at a decent speed, always to the right, the car sometimes feels like it is swerving. Is this the sensor problem?

Other than these things, the car has been great. I have had it for 4 years, and have put over 100,000 miles on it. Only in the last 6 weeks or so have I had any real trouble at all.

I would suggest that everyone get a subscription at Chilton DIY for self repair. This car was made to be kept up in a shop, and unless you have the manual, you will be at the mechanic's mercy. A lot of these things aren't too bad on your own, and with whatever little stuff has popped up, we've been able to take care of it.

Good luck everyone!