My 1998 RAV4 lunges after turning it off

What would cause my 1998 4WD RAV4 to lunge forward slightly after I have driven it for any distance, place it in park and then turn off the key. It does it whether my foot is on the brake or not.

Please be a little more descriptive. What exactly does it do? How hard? Dangerously? Does it do it backwards when you park facing uphill?

It normally occurs when you park on a flat, level surface. It gives you the sensation that someone bumped the rear of your car and you moved forward about an inch when it occurs. The dealer attempted to say that I came to a stop and then let off the brake which would make it move forward. I informed the mechanic that even if I stopped easily or suddenly, put it in park, took my foot off the brake and set there for 5 minutes before I shut it off it would still bump forward when I turned off the key. It has been going on for about a year. It now has 126K on it.

Just think of it as trans relaxing after being turned off.

Great site about RAV4 www.rav4world.com

It seems like the engine stops turning abruptly. You might try different heater settings or defrost settings when you shut it off. Maybe the AC compresser is still engaged when you shut it off. The clutch on it could be stuck engaged. A broken engine or transmission mount is another thing I am wondering about, although it sounds too wild to be true. I wonder what happens when it is shut off in neutral while holding the brake. Don’t forget to put it in park afterward. You have a funny one there.

Had a thought on this. I may be way off base but here goes. While stopped on a level surface with the engine running; shift the transmission to neutral; and release the brake. Does the vehicle roll forward or reverse?