Hi,
Regarding your fluid, Mitsubishis transmissions are the pickiest of transmissions I have dealt with regarding transmission fluid condition.
Old, dirty fluid as well as generic replacement fluid both can lead to mild to moderate drivability problems, typically shudders in overdrive and the occassional shift flare (light rev between shifts)
The first step with most situations as they enter the shop is to insure that the fluid is correct and in acceptable condition. If your fluid is dark and brown colored, start with a flush with Mitsubishi fluid and see if you conditions improve over a weeks time. Inside the transmission are a series of many brake discs that are saturated in transmission fluid; it will take a few days/several miles for the fresh fluid to absorb into the brake discs, and often people will report an improvement after 2-3 days, but nothing immediately after a flush.
Regarding known issus with these transmissions, just about every (Mitsubishi) front wheel drive transmission from this era had some significant shift flare issues from 2nd to 3rd gear. The problem was clearance issues between the case and reverse/overdrive drum. This is a repair that can be done on-car without removing the transmission, but still with parts is in the $500 range if this repair is needed.
Another known issue is a shudder between 40-50mph caused by non Mitsubishi fluid use or severely degraded fluid conditions due to lack of maintenance.
The approved repair steps are a full flush of the system and re-evaluate at a late date. If the problem does not resolve after a flush, torque converter replacement is recommended. This is a pricey repair, in the neighborhood of $1900 parts and labor.
For what it's worth, 2002-2005 is the most common years I run into with transmission behaviour complaints, and 9 out of 10 times a fluid flush resolves the complaint.
There have never been any recalls issued on your model for transmission complaints.
ASE Certified Technician
16 years automotive and OTR repair including specialized training from Toyota and Mitsubishi
Doug - Thanks for the quick reply I will take the car in and am guessing only Mitsubishi carries Mitsubishi Transmission Fluid?
Not to ask a double question but is the heater issue I (and it seems everyone else on this site identified) expensive as well?
You're welcome :)
Yes, you will need to get the fluid from a dealer if you have someone other than the dealer do the flush. The part number for your vehicles' fluid is ACH1ZC1X05, and a case of 12 quarts will be sufficient (you will need about 10 quarts to fully change the fluid, but most flush machines take 12 to operate)
Can you describe your heater complaint? I'm not sure what issue you are referring to.
Thanks