New to this forum. I've had since new a 2003 Santa Fe 2.7 V6/FWD/150k miles. It's a daily driver, mostly 40 miles of mixed traffic highway round trips for community, no towing at all. Done all and more than required maintenance for the car over the years, great running vehicle. Most of the repairs myself, except I had Hyundai do the timing belt at interval. Most everything else I do what I can and leave the heavy stuff to dealer or local shop.
I've always paid particular attention to changing trans fluid regularly - about every 15-20k miles I do the dump and fill with new SPIII fluid from the dealer, and I've had it flushed at dealer at 30k, 60k, 90k, and 120k with the dump/fills in between. I know its overkill for maintenance, but worked for me on other cars and this one up to now. Recently started having problems with transmission shifting erratically in the 3rd-4th gear range, almost like it is upshifting/downshifting with a lot more sensitivity, and only rarely does it feel like it's slipping. I had a friend who owns a repair shop flush/replace the trans fluid with Hyundai SPIII and it seemed to improve the shifting for a while, but the 3-4/OD shift is still floating in and out, but less frequent. The car runs through all gears in the morning when it's cold, only upshifts/downshifts in 3-4/OD when warmed up. It does settle into 4/OD when I get up to 60-65 mph / 2250-2500 rpm, pretty much stays there in gear.
Did some research and found that this family of transmissions (mine is the Mitsubishi F4A41) often has problems with the transmission input and output speed sensors going bad intermittently, sometimes it can also be the throttle position sensor going bad, and sometimes it can be the shift solenoids in the valve body going bad. I replaced the three sensors above and it seemed to improve a little more, probably because of the adaptive learning function built into the transmission control module. But I still feel the 3-4/OD upshift/downshift is unstable, not like it used to be. More research revealed that many of these transmissions had problems with excessive wear in the valve body bores or with the shift solenoid O-rings wearing out and/or the solenoids themselves going bad electrically (losing resistance in the coil over time with the excessive heat.)
So, going down the path of shift solenoids wearing down, I did the test suggested in the manual of taking the resistance readings for the shift solenoids at the exterior connector to the valve body (ie without taking the valve body trans pan cover off and not measuring the solenoids at their direct posts). My readings indicate that all of the five solenoids are around 4.2 ohms, well outside of the 2.7-3.4 ohm range in the manual. Based on this data, is it possible that the shift solenoids have worn down enough to cause erratic shifting? Is this common at 150k miles? Given that this trans has had extensive maintenance, I find it hard to believe that I might be looking at a complete overhaul ($2-3k) as was suggested by one shop. And no, I have not taken it to the dealer yet to get the trans scoped or diagnosed.
I am thinking about replacing all five of the shift solenoids to see if this improves the wandering 3-4 shift, it's job I can do myself. Has anyone had any experience with this type of trans problem? Any recommendations? Thanks in advance for your help!
I've always paid particular attention to changing trans fluid regularly - about every 15-20k miles I do the dump and fill with new SPIII fluid from the dealer, and I've had it flushed at dealer at 30k, 60k, 90k, and 120k with the dump/fills in between. I know its overkill for maintenance, but worked for me on other cars and this one up to now. Recently started having problems with transmission shifting erratically in the 3rd-4th gear range, almost like it is upshifting/downshifting with a lot more sensitivity, and only rarely does it feel like it's slipping. I had a friend who owns a repair shop flush/replace the trans fluid with Hyundai SPIII and it seemed to improve the shifting for a while, but the 3-4/OD shift is still floating in and out, but less frequent. The car runs through all gears in the morning when it's cold, only upshifts/downshifts in 3-4/OD when warmed up. It does settle into 4/OD when I get up to 60-65 mph / 2250-2500 rpm, pretty much stays there in gear.
Did some research and found that this family of transmissions (mine is the Mitsubishi F4A41) often has problems with the transmission input and output speed sensors going bad intermittently, sometimes it can also be the throttle position sensor going bad, and sometimes it can be the shift solenoids in the valve body going bad. I replaced the three sensors above and it seemed to improve a little more, probably because of the adaptive learning function built into the transmission control module. But I still feel the 3-4/OD upshift/downshift is unstable, not like it used to be. More research revealed that many of these transmissions had problems with excessive wear in the valve body bores or with the shift solenoid O-rings wearing out and/or the solenoids themselves going bad electrically (losing resistance in the coil over time with the excessive heat.)
So, going down the path of shift solenoids wearing down, I did the test suggested in the manual of taking the resistance readings for the shift solenoids at the exterior connector to the valve body (ie without taking the valve body trans pan cover off and not measuring the solenoids at their direct posts). My readings indicate that all of the five solenoids are around 4.2 ohms, well outside of the 2.7-3.4 ohm range in the manual. Based on this data, is it possible that the shift solenoids have worn down enough to cause erratic shifting? Is this common at 150k miles? Given that this trans has had extensive maintenance, I find it hard to believe that I might be looking at a complete overhaul ($2-3k) as was suggested by one shop. And no, I have not taken it to the dealer yet to get the trans scoped or diagnosed.
I am thinking about replacing all five of the shift solenoids to see if this improves the wandering 3-4 shift, it's job I can do myself. Has anyone had any experience with this type of trans problem? Any recommendations? Thanks in advance for your help!
