Please Help! My Auto Transmission Is Giving Me Problem

Please can someone help me diagnose this problem? (I have a Hyundai Sonata 1994/95 Model. Bought in Cotonou last year November.By December, on my way to Port Harcourt, the radiator fan stopped and the top cylinder gasket got burnt. Sometimes in January I noticed that oil was gushing out from where the oil gauge stick is, I took it to a mechanic and I was told that as a result of the overheat  that occurred the previous month my piston and rings had melted. The piston,rings and metals where changed. After about two months the car started smoking, and I was advised to change the engine. The car is Using a Mitsubishi Sigma V6 3.0 liter engine. Now the engine is perfect, no more overheat.)

As I said before, I have a problem that has remain unsolved since I bought this car: I noticed barely a month after purchase that sometime if I start the car and put it on drive (D) It will respond as if it wants to move, but will not until I shift the gear to L. It will then move and as I am driving I will push it back to D. At first this use to happened once in a while. Hence my reason of buying the new Engine complete with gear.

But recently this problem have persit that now I can't move the car when it's park with D, except L and during this period the gear will not select, it will be driving with only the same gear I use to move. I had gone to two gear mechanic and I was advised to change my gear in which I did, but still the problem continue with the new gear. The funniest thing now is that each time it happens and I go to the mechanic, on the way it will start selecting. Sometimes when I parked and ask the mechanic to come and check  the vehicle it will move with D and select normal. Since Monday it has been OK and selecting well, and I wanted to travel today, after buying things for my journey, and about to travel, the problem started.

Please who know what might be wrong with the car? I need help please. You can also reach me on my email: imeiquoho@yahoo.com or call: 08037221729 Thanks

In addition to mechanical problems, you night also have electrical issues. The automatics generally are controlled by an ECU (brain-box) If you were here in Lagos I would have suggested some garages where you could have a full diagnostic check done instead of trial and error. But the bottom line is there could be so any things that could be wrong, and without diagnostics, its like you are shooting in the dark. 

Boy, you've got some liver! Why spend so much and go through some much troubles with this car? 1994/95 Sonata? I think you need peace of mind not a juju you will be worshipping everyday.

Sell the car and go buy peace of mind.

All the best.