I have a Mercury Capri 1991 convertible. The car was owned by someone else briefly before I got it, but who ever had it, probably put motor oil in the place where transmission oil should go. My probelms started with the transmission when I tried to change the transmission fluid, then the transmission started acting radically. The car wouldn't go in reverse, it losted power while driving on the freeway. I caulked this to transmission damge from the change of the types of fluids. Before I changed the transmission fluid, it was viscous, and black , like motor oil.
I add more fluid, mirculously I was able to get the car to go in reverse without having do anything to it, but the transmission wouldn't engage well at low speeds, but started driving ok at high speeds like on the highway. I was stingy putting the new fluid in cause I didn't want to overfill the transmission. Recently, To make a long short short. I had to change one of the belts that go to the alternator, simply cause I drove the car and saw the battery come on, luckily I arrived home to time as radiator fluid started venting from the hood of the car. The next day, I discovered the belt ( alternator ,waterpump, engine) was missing. I seeked to replace the belt. With an original belt as a template, ( but somewhat damaged) I replace the belt with a new one, however it was extremely difficult to install the belt as I guess it was a very tight fit, plus there was no room for adjustment on the alternator. The Alternator was set at its most minumin adjustment. In order to get the belt on the roller, I ended up accidentally rotating one of the rollers located near the engine, oil pan. Turning that roller made al the differance in installing that belt, it helped give me enough torque to place the belt on the roller. Now that belt seems a bit tight ( but the car doesn't make that squealing noise that a car makes when a belt is slipping on a roller, that car used to be real annoying to drive that way).
But now something as changed,with way the tranmission works. The tranmission didn't seem to work 100% on that car, giving poor performance at low speeds ( city driving), but good performance at high speeds as the automatic transmission wouldn't engage very well. Now the car won't run well at high speeds now. I added some transmission fluid as maybe the car was driving like there wasnt enough fluid in it, the car showed some improvement, but still drives on the freeway poorly as it refuses most to engage at high speeds making it so that it runs at high rpms, so that I have to slow down. The engine sounds like its working harder. Why did this happened? Could it be caused somehow by by my repairs, the new tigher alternator belt, or did I somehow upset the timing by having to turn that roller to get that belt on, thusly affecting the transmission performance , or could the car have suffer sever engine damage when it overheated ( because of the missing belt), it didnt seem like it. The car used to drive well on the highway. I could travel out the city 50+ or so ( with a questionable transmission) miles, now I dare now travel outside the city. Can anyone help?