1993 Nissan 240SX - Transmission failure?

[Invictus]

Why can't this kind of stuff come at a convenient time?

I'm having issues with my '93 240 SX (Automatic, ~140K miles) which I think are related to the transmission. I left home to pick up a friend less than a mile away, and was in Park outside the building while waiting. My friend got in the car, I shifted into reverse to back out, and then shifted into Drive and found that I was still drifting backwards -- I was on a hill, but not a very steep one, enough that I should have been able to idle over it. I gave it some gas and was able to move forward, but shortly afterwards when I would step on the pedal, the engine would rev, but I would get no acceleration. I pulled to the side again, turned off the car, and turned it back on. It seemed like it was running fine again, until I got about 30 feet further and it happened again. I ended up having to repeat the process over and over until I found a parking lot I could leave the car in. At first I thought I was crazy and had just put it in neutral, because that's exactly what it felt like -- but sure enough, I was in drive. I have also tried reverse, only to produce the same results. It seems like it's working for just brief periods of time after being off -- but I have not tried moving it since I originally parked. Didn't want to risk causing any more damage than may have already been done.

I came back later this evening after searching on the symptoms and checked the transmission fluid, which was fine. When I had my oil change about 1000 miles ago, I had all of the fluids checked then as well. One thing I did notice when I came back to the car and started it up was a very loud whining sound from under the engine, that tapered off after about 5 minutes of letting the car run there in Park. During this time, it would idle at around 900-1000 rpm (not sure if this is helpful at all).

I have noticed recently that the transmission seemed to slip a little at low speeds, but I figured it was due to the age of the car. This was the first time I've noticed anything close to this kind of symptom. I checked under the car for leaks, and found nothing. Nothing out of the ordinary has happened recently -- I just made a 200 mile trip to SC and back without incident.

I'm parked in a zoned lot, so I will have to get the car towed to a shop first thing in the morning, but since I'm not too mechanically inclined, I thought I'd check here with you all to see if you had any ideas of what could be wrong -- maybe I can avoid getting too ripped off by the mechanic .

If any more information would be helpful in diagnosing this, please let me know.

Thanks!

[180fan]

have you checked the fluid level and the color?

[Invictus]

I checked the level, and it was fine. The color, I could not check - it was at night and all I had was the poorly lit streetlamp nearby to see with. It's already been towed to the mechanic, so I'm waiting for a diagnosis from them before proceeding with any work on it.