Hello Scotty my name is Rhonda and im from Houston Texas. I have a question about my 2016 Jeep Patriot Latitude, 2.0.

My engine overheated and I took it to a local mechanic that was highly recommended to me by a friend of mine. The mechanic was supposed to replace the engine with another one from a Junk yard one but he was going to give me a 10,000 mile warranty on it.  The only issue it had was I hit a pothole here in Houston And unbenounced to me I damaged my radiator and it caused it to leak and the next day i noticed it was over heating so I stopped and called a wrecker and towed the vehicle home and then I made a mistake by calling a so called mobile mechanic off Facebook and he came to my house and removed the heads Off my motor and I paid him $1200 to take the heads to a machine shop to have them fixed and he took off with the $ and the heads to my motor!

So a few days later I had it towed to this mechanic and he said he was going to replace the engine with one from a Junk yard ( I know that wasn't the best idea but considering the fact that I still owe over $5,000 to my bank on this vehicle and I just needed it to run long enough for me to pay it off) I couldn't afford to continue to pay on this vehicle and buy a new one. 

Well my issue is he called me about a month ago after having my Jeep for over 4 months and he told me it was finally ready for me to pick up! So I was happy and I went to pick it up and took it for a test drive and noticed the vehicle wouldn't accelerate over 35 mph so I took it back and told the mechanic something wasn't right with it.

He opened the hood and I noticed on top of the engine it said 2.4 And my vehicle is a 2.0! So I told him that I'm not a mechanic but possibly that could be the issue with my vehicle that he put the incorrect size engine in the jeep. He kept on telling me the engines are intrachangable and that couldn't be the issue. But I refused to pay him for the work and I told him to figure it out and fix it and once it was fixed I would be back to pick up the jeep and pay him the remaining amount I owed him ( I had already paid him $1500 to buy the used engine)  he called me a week and a half later and he said he replaced the engine for the correct 2.0 one but that my vehicle was still not accelerating over 35 mph!

He started suggesting that I take it to a transmission shop to have it looked at but my question is....should I do that myself if I know my vehicle didn't have any prior issues with the transmission before I took it to his shop, or should I tell him that it's his responsibility to figure out what he did wrong to my vehicle by installing the incorrect engine in my vehicle? Also can that cause issues with my transmission if he put the incorrect engine in my vehicle without upgrading or programming anything else such as the ECM, OR Tcm on my Jeep allow it to run with a 2.4 engine and since he says he replaced it with a 2.0 like he he should have in the first place should that have fixed the issue of the jeep not accelerating?

I am just upset and confused how he didn't check what size engine my vehicle needed before he installed it. Any advice on what I can do would be greatly appreciated Mr Scotty thank you sir, I really wish ALL MECHANICS WHERE HONEST LIKE YOU ARE.