Ford Focus Idle Too High

My wife has a 2003 Ford Focus. It idles very high, and it has become very annoying. When you first crank it up, it sounds like a jet airplane, because it is so loud. It is very embarassing, to say the least. After you drive the car for a while, and shut it on and off a couple of times, it drops down to a more acceptable range for the sound. When it is so noisy, the car will vibrate, especially the dash.

A lady that works with my wife said they had a 2004 Focus that was doing the same thing. They added a couple of STP fuel treatments, and then had the fuel filter changed, and it cleared their rough idle up. We have done the fuel treatment thing, so I guess we may try the fuel filter next and see if that helps.

Any thing else that we could try? Any input would be appreciated. Thanks.

 

try to remove the throttle cable from the throttle lever and start the engine. if the rpm is still high, remove the air hose from the air intake to see if the throttle valve is closing properly. with the cable disconnected, the throttle valve should be completely close, if not check for any obstruction or sticking valve shaft. if the rpm drops to normal with the cable removed, your accelerator cable might be binding and has to be replaced. fuel filter has nothing to do with engine racing.