Engine Idle problem

[allizdog]

Hi, I'm hoping that someone here can help identify the problem with my PT. I have a 2002 PT 2.4L auto. The problem is that it is idling high. With the car in drive and the brake on, it idles at 1100 rpm. If I put it in park it jumps up to a little over 2000 rpm. If I pump the pedal once while it's idling at 2000, it'll drop down to 1500 but will pulsate. This started happening a little over a week ago. At first, the check engine light was not on. Then it came on and remained on for a few days. Now it is out again, although the problem is still there (not that I expected it to go away by itself, that would be too easy). Any thoughts on what the problem is, or ideas on how to fix it? I was going to bring it to have the computer read but I don't know if they'll get a code if the check engine light is no longer on. Thanks!

[CREWZIN]

Welcome to the forum.

Your problem could be the IAC (Idle Air Controller) located in back of and attached to the Throttle Body (see picture). It can be taken off and cleaned or replaced pretty easily. It controlls the Idle.

The check engine light stores a code into the computer and can be read even if the light isn't on. Auto stores like Auto Zone can read the code for you at no cost. We have lists here on the forum that will tell you what the code means.

[allizdog]

Thanks! I'll have to run to Autozone sometime today and have it checked. I'll have to check your photo at home, it won't load here at work (they have lots of sites blocked, including photo service sites).

[allizdog]

It turns out to be a leaky vacuum hose. When I removed the cover, the hose that runs from the manifold to the throttle valve (I think) had split at the nozzle. I just cut off the end and reattached. I'll have to get a new one at some point as it seemed as if it was deteriorating, it was real soft and mushy (best I could come up with to describe it). It almost seemed as if where it split, it had melted. Anyway, thanks for your help.

[CREWZIN]

Your welcome. Glad you found the problem and it was that easy to fix. Problems over the internet are sometimes hard to diagnose and we can only take an educated guess as what it might be without actually seeing for ourselves. Take a good look at all the hoses and connections as a precautionary measure while your fixing what you found.

[allizdog]

I will check the others, especially since the one that was bad seemed as if it had melted rather than got old/brittle and broke. Something to keep an eye on.