# 05 pt cruiser rough idle **URL:** \ **Category:** Maintenance/Repairs\ **Created:** [September 27, 2015, 1:56am UTC](https://community.cartalk.com/t/05-pt-cruiser-rough-idle/91287 "2015-09-27T01:56:32Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![system](https://global.discourse-cdn.com/cartalk/original/3X/1/d/1d47c66a543aa6c5a7873bb2320858f978ff52ed.png) [@system](https://community.cartalk.com/u/system)\ **Post date:** [September 27, 2015, 1:56am UTC](https://community.cartalk.com/t/05-pt-cruiser-rough-idle/91287/1 "2015-09-27T01:56:32Z")
I have an 05 pt cruiser that idles rough sporatically. Sometimes it idles smooth, sometimes it is rough but will calmndown when i shift into gear, and sometimes it is rough when i let off the gas and come to a stop sign. When i first crank the car, the idle is rough and will act like it wants to cut out when i first back out of the drive way, but it clears up and drives better after getting gas. I have changed the plugs and wires, which did help, but there is something else still causing some problems. When at cruising speed, you cant detect any stutters or other problems. I looke at the vacuum lines and have a bottle of injector cleaner on 3 tanks of gas back to back with no apparent change. What am i missing? I did put a PCM on it a few years back, is it possible it has gone bad? The gas milage also has seem to be suffering. I also checked the air filter as a possible problem, but it is very clean. ---
**Author:** ![db4690](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/db4690/32/2583_2.png) [@db4690](https://community.cartalk.com/u/db4690)\ **Post date:** [September 27, 2015, 5:47am UTC](https://community.cartalk.com/t/05-pt-cruiser-rough-idle/91287/2 "2015-09-27T05:47:36Z")
@redneckredz Is/was the check engine light on . . . ?! If so, what fault codes do/did you have? After telling us what codes you have, I would thoroughly clean the throttle body and the idle air control valve By the way, why did you replace the PCM . . . ? ---
**Author:** ![system](https://global.discourse-cdn.com/cartalk/original/3X/1/d/1d47c66a543aa6c5a7873bb2320858f978ff52ed.png) [@system](https://community.cartalk.com/u/system)\ **Post date:** [September 27, 2015, 9:42pm UTC](https://community.cartalk.com/t/05-pt-cruiser-rough-idle/91287/3 "2015-09-27T21:42:53Z")
No engine codes at all. I changed it a few years back because it had over 150000 miles and figured it was due. ---
**Author:** ![knfenimore](https://avatars.discourse-cdn.com/v4/letter/k/9fc348/32.png) [@knfenimore](https://community.cartalk.com/u/knfenimore)\ **Post date:** [September 28, 2015, 6:19pm UTC](https://community.cartalk.com/t/05-pt-cruiser-rough-idle/91287/4 "2015-09-28T18:19:54Z")
If the maf is dirty it will cause rough idle. Also, dirty iac and intake will cause it. ---
**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\ **Post date:** [September 30, 2015, 7:53am UTC](https://community.cartalk.com/t/05-pt-cruiser-rough-idle/91287/5 "2015-09-30T07:53:03Z")
If it idles poorly but runs ok at higher speeds, a vacuum leak can cause that. You get a too-lean mixture at low speeds, but at higher speeds, going uphill, etc, the vacuum leak is such a small percent of the total amount of air being drawn into the engine, the symptom disappears. Suggest a complete vacuum system check-up. This includes looking for loose or broken fittings, and checking all the vacuum operated components for internal diaphragm leaks. ---
**Author:** ![system](https://global.discourse-cdn.com/cartalk/original/3X/1/d/1d47c66a543aa6c5a7873bb2320858f978ff52ed.png) [@system](https://community.cartalk.com/u/system)\ **Post date:** [October 14, 2015, 5:46am UTC](https://community.cartalk.com/t/05-pt-cruiser-rough-idle/91287/6 "2015-10-14T05:46:59Z")
Well, after getting the car out of the body shop after hitting a deer, the idle problem has strangely enough left as mysteriously as it started. ---
**Author:** ![oldtimer-11](https://avatars.discourse-cdn.com/v4/letter/o/e79b87/32.png) [@oldtimer-11](https://community.cartalk.com/u/oldtimer-11)\ **Post date:** [October 14, 2015, 7:34am UTC](https://community.cartalk.com/t/05-pt-cruiser-rough-idle/91287/7 "2015-10-14T07:34:30Z")
No engine codes at all. I changed it a few years back because it had over 150000 miles and figured it was due. …That is the strangest thing I ever heard.