Q: Car running fast after warmup.

Having your car run fast like this sounds like a frustrating experience. Let us get you pointed in the right direction so you can drive your car worry-free. The symptom you are experiencing with your vehicle sounds like something called a high idle. There are several causes as to why this happens. The more common reasons I have seen in my experience include a vacuum leak, a dirty or sticking throttle body, or an idle air control sensor failure. As seen, due to the symptoms you are experiencing possibly being caused by more than one culprit, it is best to enlist the help of a certified mechanic. This mechanic will be able to properly verify why your vehicle is experiencing a high idle and repair the reason behind it quickly and efficiently.