High idle, other problems

When I start my car up it idles up very high for a second, a lot higher than it used to, then it goes down. Sometimes it will continue revving up and down slightly for a little while before it settles down. Now recently I've noticed that if I park the car while idling it will climb past 200 degrees. It gets about halfway between the 200 and 260 marks. Then when I drive it will drop down to 200 again. Any ideas at what my problem could be?

When I start my car up it idles up very high for a second, a lot higher than it used to, then it goes down. Sometimes it will continue revving up and down slightly for a little while before it settles down. Now recently I've noticed that if I park the car while idling it will climb past 200 degrees. It gets about halfway between the 200 and 260 marks. Then when I drive it will drop down to 200 again. Any ideas at what my problem could be?

Having that problem myself, without the high temps, that is. Someone suggested a clogged EGR valve. Haven't had a chance to look into it yet, but that may help.

Well zr440 what year and engine do you have ???????

Sounds like a cooling system problem on the temp issue.

On the high idle, check for vacum leaks.
Also check your IAC as this controls idle.

hope that helps.