engine idle speed adjustment on 1992 Mercury Sable

my engine idles around 1000 rpm and when I go from park to drive or drive to park the transmission makes a loud engaging noise. Is the rpm set to high and if it is how do you make adjustments

Asked by for the 1992 Mercury Sable
sound to me like either an engine or trans mount
2 more answers
Sounds like this vehicle might be new to you, if so you need to know that these vehicles do not have idle adjustment recommendations. They are preset at the factory and should be fine through the life of the vehicle if all other things are normal. When other problems occur, they can cause the high idle. It should be checked by someone with a Ford compatible scan tool, they should check the duty cycle of the idle air control valve and they should be able to figure out if the idle is improperly adjusted or if another condition exists. You could have sensors that are sending the wrong values to the engine control module and this can cause you symptoms, that is why I recommend finding a good shop. An experienced technician should be able to figure it out for you.
When you start up a cold engine, it will initially run about at 1000 rpm. This is a natural thing on this car model.

You just need to wait for about 1.5 minutes, and automatically the idle speed will descrease to about 600 rpm.

When the engine warms up a little bit, and the idle speed descreases, you can shift from parking to drive without making that alarming noise.