96 Ford Taurus LX idling/slipping issue

On my 96 Taurus LX 24V, I noticed two issues occurring lately. When I am stopped at a light, the idling will jump quickly from 600-700 RPMs to 1K, back down to 400 RPMs and then go back to the 600-700 RPMs. This happens once, on occasion twice at a light. When I put it in Park, it doesn't do that. It seems to happen only after 10 min of driving and not right after having started the car.
The second issue is that when I'm in first gear, when I accelerate, the engine will rev for a second (the car will have no power) and then drive fine. It only happens, when I'm in first gear, or if I slow down around a curve. Otherwise, the transmission shifts beautifully in all gears, acceleration and deceleration.

My car has been leaking engine oil significantly for the last two months from the upper part of the engine and the mechanic said that it would not be cheap to replace the seals leaking around the chain area. But, would the two things be related? Does it seem like a transmission issue? Any help would be appreciated.
Michel

When the idle speed jumps, by any chance is the A/C or defroster on? If it is, it could be the A/C clutch causing a load on the engine and the computer is trying to compensate through the Idle Air Control valve. You might want to check that A generic picture will be below.

On the transmission problem, have you checked to be sure the fluid is full? It needs to be checked when the engine is at normal temperatures. It needs to be placed in park and on level ground. If it is low, that could be your problem. You might just need a transmission fluid and filter change.

http://i153.photobucket.com/albums/s214/way2old1/idlemotor.jpg

I just checked my automatic transmission fluid. The level is at maybe at the end of the curved dip stick at the bottom of the stick, which below the dot on the dipstick that tells you not to drive the car if it's below that. I really believe this is the issue. I am going to slowly fill it up a 1/4 of a quart, at a time, as the manual says to do.
Regarding the idling issue, it does it without the AC on. It does it once when I stop at the light and it stops. Does it again the next time that I stop. It's more annoying than anything. But the slipping, I have to solve. Thanks.

Michel

You may still want to check into the IAC for the idling problem. It is easily removed and you can get some spray cleaner that will not damage the rubber parts inside the valve and see if it helps any.