Hello I just recently bought my first Mitsubishi. It's a 2003 Mitsubishi Montero sport 3.5L v6 AWD/four-wheel drive with 173,000 miles on it. Im really enjoying it but I'm concerned about an issue it started having about 2 weeks ago. It's a four speed automatic and when im driving and it gets to fourth gear the torque cuts in and out with my foot in the same position on gas pedal. When I give it more gas it does accelerate but not as quickly as it does going from first to third. I've checked the tranny fluid, and ran seafoam fuel injector cleaner through it and still having the issue. I'm really hoping it's not my transmission or transfer case. If anyone can help out me figure out this issue please let me know. I can repair myself just need to know the issue. Thank you

 

It's possible that you are having an issue with torque converter solenoid locking/unlocking. Do you have C/D (Central Differential) yellow light flashing? If so, it will tell you which error code transmission is experiencing. If not, it might be a good idea to take it to the shop where they can pull transmission error codes and run diagnostics.