Pontiac Problems? Ask a Mechanic for Answers ASAP
Hello and welcome.
OK. Several things here.
!. if you had to add antifreeze, then it was low so it is leaking or burning. A pressure test of the system would be needed. Some common areas are the water pump or intake manifold. You may still not have heat because the system has air pockets in it. it may take a while of running to get the air out, then fill it up again and re-assess the no heat problem.
2. Passenger window could be a bad motor or switch. If you can hear anything moving but wont go up or down, then the motor regulator is broke. If you do not hear anything, look at the interior light to dim a little when hitting the switch. If it does then motor is probably bad. A switch would cost approx. $75. A motor / regulator is around $250-$350.
3.The engine died out could many, many things.
You are going to need to get these things diagnosed by a mechanic. Expect to pay 2 hours shop labor to diagnose these problems.