I have a 2001 Mazda tribute that was a great suv, it was my mom's car and I bought it from her and then bought her a new used car. The thing is she never did ANY maintenance to it and well to give you an idea she only bought used tires and whichever was cheapest and just drove it until they needed replacing because the wire was showing. I decided to do all the maintenance items that I thought should be done, started with the coolant, she had poured a bunch of the bars coolant stop leak in it because it had a leak in the radiator (I think) so I did the flush and then changed the oil and the filter. Completely black and smelt burnt. Then drove it around for a while and had no issues maybe 100 miles or so, around town and highway driving. Then I let my fiance drive the car on the freeway and she had no issues until she got off the freeway making me think it had just enough airflow to keep the engine cool. once she got off the car just stopped and she pulled over and it wouldn't turn back over. That was between 6:30-7 in the morning so a little bit cooler. I got there and the gauges weren't working, nothing was so I then disconnected the battery and tried resetting things and hooked a jump pack to it. I then tried myself to start the car and it was just clicking and I thought maybe the alternator was bad and the battery was dead and the starter couldn't start it. However I noticed the gauges kicked back on and that it was all the way at H so we sat there with the hood up after a little while the temps were getting back down and I was able to drive it about .5 miles to my house. I then checked all the fluids, gas, coolant and oil and everything was perfect. Thought it was some weird fluke (stupid idea) I ended up giving her my car and then I tried driving her car somewhere and while I was on the freeway I heard the clunking and immediately thought it was rod knock so I got off and pulled into a parking lot. While I was there the car looked fine but I got it towed back home. It has been sitting ever since then. I want to know is there anything I can do to bring this car back without an engine swap? Is there a way to see if the engine is good or to find out what needs to be done. I don't want to start taking things apart or buying new parts for it because it has hardly any value left in it. Like I said it was a great car before this happened i think the only thing was when coming to a stop at a stop sign early in the morning it would sometimes stall out or fluctuate in rpms while slowing down. Im pretty sure I fixed that issue and don't remember what it was. Any guidance on this at all would be a great help. My fiance and I brought both of our kids home in that car so there is sentimental value in it so I would like to take a drive in it one last time and then part ways if possible. If not its getting sold or junked.