1998 civic trans problem
 

Hey I have a 1998 Honda civic LX with only 82k miles, and I bought it recently within the last month. When I test drove the car I did not notice any problems but starting about a week or 2 ago, the second shift was a little hard and would flare. It tends to happen 10 minutes + into the ride where the car warms up.

So i decided to do a transmission fluid change so I went ahead and drained it and noticed the transmission fluid is a little on darker side but on top of that it was over filled, there was a mass amount of it just coming out.

I replaced it with mobil 1 synthetic automatic transmission fluid. But i went out for a test drive and noticed that it didnt really do anything. On top of that, now i can feel it without the car really warming up as much.

Does anyone know what it could be? the solenoid? maybe a vacuum leak (because i can hear a slight whistling sound when i shift to drive). i could use all the help please. thanks