I have a 2005 Malibu Maxx that the transmission seems to "free wheel" when you let off the throttle. When you depress the throttle again to resume speed rpm's increase then you feel trans engage

 

the maxx should have a trans dipstick. Check the fluid level, could be low fluid. If the fluids is low better check for leaks.

While your at it check the condition of the fluid. It should not be brown and burnt; an indication that something is slipping in the trans.

fluid and filter change interval is 60 000miles. Do it when its due.

 

The 05 Maxx has a sealed trans; there is no dip stick.

The vehicle trans should be checked by qualified personnel.

 

whoops your right...thought the 3.5 maxx engine was coupled to something larger than a 4t45.

you can still check the trans fluid level at the oil level control plug but you do have to know what your doing.