2006 Ford Taurus

My 2006 Taurus has always had a idleing problem. When idleing the RPM gauge flutuates up and down and the engine surges. The idle is rough at times and smooth as glass other times. It has done this since new and the dealer cannot find the problem. It does not always do it and there is no common denominator that is causing it.
When AC is on the idle will go way down to the point the engine growls and then will idle back up to normal and then go high and then back to normal. It repeats this over and over. The car only has 18K miles on it now and this problem has been with me since day one. Any suggestions? Car has a 3.0L V6.
September 15, 2007.

I sincerely hope the car is still under warranty. Normally, I would suggest checking for worn hoses first, since they are the cheapest, but a car this new is not expected to have any bad rubber. If this has been happening since day one, then you may have a lemon. I'm not sure what the laws are in your area, but you shouldn't have to pay for this kiind of problem.

Sep 24, 2007.
Maybe you have a dealer like mine. They take your money and do nothing. I have stopped going there. Complained to ford with no results at all.
You should clean the IAC, MAF and the throttle butterfly and throat. There are you tube postings to help you with these procedures. It sounds as simple as that to me.

Dec 14, 2010.