Hey guys I have an 02 Diamante Es and for some time now I notice an anti-freeze smell in the car when I turn on my heating/ac. I don't know about over there but, here in the states Diamantes have a big problem with their heater cores failing. It was never recalled by Mitsubishi but it was and still is a huge problem. What can that smell be? A leak? My car runs perfect never stalled, left me stranded, ANYTHING! This smell is raising a couple concerns though.

This could be your heater core leaking. I had the same problem, it was leaking down onto my carpet, smells terrible. It is located behind the centre dash, fairly big job i belive, as you have to remove the whole dash... aparently, dont tale my word on that one.

+1 for heatercore. You can either bypass it (now sure how on Magnas) or pull the dash and fix it.

Good luck mate.

It's not the heater core itself that fails. Where the pipes bolt to the hear core there are two rubber seals that leak.
The seals cost $5 from Mitsubishi and the job can be done at home if your confident. You have to remove the whole dash assembly to get to it. There is a lot of labour involved and gets expensive if you take it to a workshop.
Here's a guide written by Mal, Heater core removal. (http://www.aussiemagna.com/forums/showpost.php?p=1020809&postcount=14)

Man that sucks. One of the downsides to having a Diamante.

yeah im in nz and managed to get one of the aussie made imports. dont see many, wonder how many aussie made diamantes (magnas/verada) made it to NZ?

pull the carpet up, in the passenger foot well, normally its on our passenger side, (your drivers) so i can only assume that it was also relocated

I did this job last year. Mine failed one night coming home and stunk the car out badly. The quote for Mitsu to do the job was over $1000. I did it myself. I needed two seals and they were under $2 each. If you get a dealer to do it make sure they don't sting you for a damaged heater core. A couple of dealers said that may be the problem but it was merely the seals that deteriorated. I got to admit, not the most exciting job I've done on a car. Every piece that needed to come off required another two pieces to come off first.:tired:

I did mine recently made the mistake of buying a reco heater core only to find it was the rubber seals. Cleaned them up, put a smeer of gasket silicon put it all back together. Lived with smell for a while then had the carpet steam cleaned using on of those hire jobs from the supermarket finally got the smell out, did the rest of the car and seats while I was at it. Looks awesome and best of all smell and leak gone. Job took two days, though I did start on Friday night. Take your time and don't force stuff, Mitsubishi probably put the heater in soon after the body shell was made.

Yep Im voting for heater core/seals it is a common problem in virtually all makes of cars not just Mit's. The last one i did was on a Rodeo same story the seals on the core pipes. While it is a big job it is something you just plod along with & should be achievable by most mechanically minded people. Patients is the key if you dont have patients then dont even attempt it. Taking your time you could do it easily in a weekend. Takes the pro's approx a day.

Oh testing for the heater leak : let the car run till to tempreature for at least 1/2 hour then lift the passengers side carpet up. (you dont have to undo anything). Just pull the carpet away from the firewall & stick your hand down under the carpet, making sure you actually get your hand into the underfelt stuff. (as the carpets are quite often plastic backed so, any water under the carpet isnt allways redialy noticed) you should feel wetness & warmth. The only true way to check is to pressure test the system. I.E. put the pressure tester on the radiator & pressurise it , leave it for an hour os so & it still should have pressure (exactly the same as when you left it).

No need to pressure test the system

Not sure if you ave LHD or RHD given you are an international member however on the LHS of the car, lift the carpet and look down there. You will see a white plastic cover where the engine harness comes in, this will be the first place the coolant will run down after it has run off your ECU

It is a common issue, mits were really stupid with the design, the alloy core is great, why they did not use alloy pipes welded to the core has me dumb founded but then agian I make a living from doing them lol

Get new seals, be careful when you remove the box that you do not break your plastic pipes. To assist remvoe the bolts from your aircon and fan boxes, leave them there but let them move back a bit to assist the heater box coming out

Also, Mits do not have heater taps so turning off the heater will only serve to redirect air around the core thus no heat, it will still leak just the same

mits were really stupid with the design, the alloy core is great, why they did not use alloy pipes welded to the core has me dumb founded but then agian I make a living from doing them lol



I've never attempted this repair (yet) but do you think it would be a good idea to get a heater core made up with the inlet and outlet pipes made from aluminium and tig welded to the core... certainly shouldn't leak ever again me thinks......

I'm thinking of doing this if/when it happens... shouldn't cost a lot to get the pipes/flanges made up....

Steve