Long story as short as possible. I had a 98 navigator with a cracked radiator. I used some jb weld silicone as a temp fix but it was cracked beyond where I could reach so I finally got a backyard mechanic to swap it out (new radiator purchased on Amazon). It never overheated, as soon as it would start getting hot, we’d pull over and get some water in it As soon as he was finished swapping the radiator, we drove it around the block and the idle was rough and the car was bogging. Drove it about 15 miles to work and it started misfiring (cylinder 4). Got it home, tried to go to work once more today and it continued to misfire and just in general have a rough ride, but then also began getting hot.
Is it possible something wasn’t done correctly when the radiator was put in? We didn’t replace the thermostat because it hadn’t come in in time. Could that be affecting anything? It’s strange because with the cracked radiator, it was driving completely fine aside from the leak, and right after changing it, we’ve had issue after issue. What could be causing it?