My car cannot stop running

have anyone experiance that when you turn off the engine and take out the key, the starter tries to kick in until you put the key in and let the engine start. it is so strange. and i also hear a heavy noise comes from my left side of the car.

“The starter tries to kick in”??
I’m not sure what that means. Is the starter actually spinning the engine?

If the starter is actually running, then it is possible that this car has a malfunctioning remote starter.
If this is a used car, you may not be aware of what was installed by a previous owner.

If the starter is not running, it is possible that you have “dieseling”–also known as run-on–taking place. This happens when a piece of red-hot carbon in the cylinder keeps igniting gas even without any power to the ignition. However, this was much more common on old carbureted engines, and should only take place on a modern fuel-injected car if there is a leaking injector or two.

How about helping us out by revealing some vital information, such as:
Model Year
Odometer Mileage
Type/Size of engine
Date and odometer mileage of last major (spark plugs, air filter, fuel filter, etc.) service

It sounds like the ignition switch is shorted to the START position while it is in the OFF position. The noise you hear may be the starter running. The trouble may also be due to a remote starter system like VDCdriver stated. You shouldn’t drive the car until this problem is resolved.

It is a 1999 Lexus GS300, and it has about 135000 miles. because i could smell alittle bit burning plastic. i was so afraid the engine will break. Do you think that would be a computer problem? because i have never experienced this kind of problem in my 97 Acura before.thank you for helping.

The burning plastic smell could indeed be the result of a short-circuit in the ignition switch or in some of the circuitry. Before you report to us that the car was consumed by fire, I suggest that you get it to a qualified mechanic. Please note that “qualified” does not include Midas, Meineke, Monro, Sears, Discount Tire, Mr. Tune-Up, or any other chain operation.

thank you for your suggestions, i will get it to a qualified mechanic as soon as possible.