Anyone have any ideas to this problem as its been doing it for a couple of months.

When idling, say at lights, the car gives a judder every now and then. I believe it only happens when the air conditioning is on and when the aircon solenoid kicks in and out. The car runs perfectly other then that and has great fuel consumption and only shows this problem when standing still. Any ideas.

Sounds serious Bob. You'll just have to keep them wheels a turnin somehow mate and not bother stoppin at the lights. Try your luck to see if there's no coppers about to grab you.

Seriuosly haven't heard this one before, has anyone else?

Mine does it and a few other Chryslers Ive driven do it aswel. The revs are up and down in some cases can be severe in an auto. Manual is not as bad but can cause it to stall, even the auto's can stall. Not sure what exactly it is But it usually happens after a service at Chrysler and have found it goes away when revs are slightly increased at the throttle body(Minor adjustment) But I am not a mechanic, But I have found it is always after a service and it used to happen when i serviced my old cars myself. It usually is OK for a day or 2 after the service but then starts to happen and it is more noticable during summer with the aircon on. The Voyager I drive at work all day tends to do it quite often and can give you a scare at lights when it suddenly gives a jolt and revs higher by itself and can stall at lights when stopping quickly. I have been told this is gear box flare??? By the Chrysler tool operators.


But I would like to hear from others aswell who have had this problem or can shead some light.

Although I work at a Chrysler service Centre They tend to overlook workers problems and also there own company cars. Well maybe just where I am. We have new owners whether that will make any difference later on who knows. The Mechanics are still the same but......

Very strange, will try turning up the idle slightly whilst waiting to see if anyone else has any solutions, and yep mine is an auto so can be serve sometimes.

well at least I am in good company .. had it with BOTH pts .... was told it was a figment of my imagination (I was / am pareniod).. so stopped noticing it not sure if there is a pattern any more .. hoping it would go away then when I think it i has it returns in my imagination of course !! I wondered when I had the crusie control glitches a few weeks ago they were related??? .... sometimes Ps&Rs is a chugger when starting too ... stales before I can get the revs up .. again NO witnesses ... sorry I'm not much help .. maybe I should keep a LOG book in the car & write the date and time and conditions . but that would be WORSE than taking pics while driving !!

Only my view (as a retired mechanic but check with Sam at MPOAR MOTORS)- With the automatic transmission flaring make sure you are definately using the correct Trans oil not a compatible one.
With the Idle issue sounds as if the Idle up solonoid is reacting a little slow. You could clean inside the throttle body (with the correct Throttle Body Cleaner) to remove carbon/tar and make sure there are no vacuum leaks anywhere as this causes havoc with the idle speed aswell.

- Ray

Hi Ray, what do you mean the throttle body and what cleaner would you recommend.

Bay Cruiser wrote:
Hi Ray, what do you mean the throttle body and what cleaner would you recommend.

Hey Bob I think he means a mixture of Ethanol with a big dash of Nitro and a spurt down the 1/4 mile track to blow the cobwebs out of it.

Had the idle speed sticking a fair while back, like about 3 yrs ago and the throttle body was cleaned when serviced and haven't had a problem since, although mine's a manual. Sorry, just remembered since then I had to fit a new idle motor in mine as the solenoid started sticking and it wouldn't idle at all and stalled unless you stuck the revs into it.

Pretty sure it isn't related to your problem though. Ones an auto and mine's a manual.

The throttle or idle solenoid get a carbon build up and as Ray said it slow to react, if you changer your own plug when you take the manifold off remove the other cables and remove the manifold from the engine completely and use carby cleaner usually works fine just need to look out for soft plastics that may react with the cleaner in other word go steady. Other faults is a slow idle return or even a feeling like a sticky throttle just some other thoroughts.

Reads like schnaps time Keith...lol ...but we got the gist.

The Throttle Body is attached to the Black (or blinged) plastic Intake Manifold on top of the engine.
If you take off the Air Filter Housing it is attached to the Throttle Body.
Looking in it you'll see a round "Butterfly" which opens and closes when operating the accelerator pedal/cable. If you open it right up look inside and you may see alot of carbon/soot build up. This can be dissolved with Wynns Throttle Body Cleaner (a pressure pack can). They do give a warning that it may harm plastic bushings on the Butterfly Pivots but to be quite honest I dont know if Chrysler have these in the PT without researching.
I've used it for years on all cars and never had an issue.
In simple terms the Idle Up Solonoids function is - the moment it detects something has come on ie: airconditioning, auto transmission gear changing, power steering turning, radiator fans etc by a heap of sensors around the engine. This solonoid opens up slightly and allows the engine to idle slightly faster to keep the engine idling smooth. At the same time when you turn the engine off it makes the idle return back to a "base idle" to prevent the engine from running on (pre ignition). This would be more noticable with the Automatic models.
Geez I hope I said that all ok.
Anyway next time you get the car serviced you can ask your mechanic about cleaning this Throttle Body.
For the exercise, next time when your in the car turn the steering wheel slightly when idling and see if your idle increases.

- Ray

Thanks guys its sounds like the problem. Plugs are due in about 4k so will look at it then.

Sounds good to me Might try it on mine aswell. I never did trust the mechanics who do my car. Proves it now

This certainly beats the old saying "you can't teach an old dog new tricks."

Certainly if you ask a question here there are some new tricks to be learnt all the time.

I hope everyone's contribution helps not only Bob but everyone else who thinks they have the same sort of symptoms. I know I had mine done as stated before above a long time ago.

Occassionally I run a couple of tanks of 98 through the fuel system and that seems to help a lot.

My previous PT (now CCPT - and auto) had a slight judder at one time. You could set your watch by it. At idle it would occur ever 13 seconds. I run virtually exclusively on Shell V-Power. One day it was not available and I had to go with 92. Under load from standing still and in a hurry get out of the way of a big truck it did not shudder but totally coughed and spluttered before getting mobile. Turned out that it was a faulty plug lead and plug. Surprised me that it was virtually unnoticeable on 98 yet most pronounced on 92.

Sound like it is a common problem, I suspected the plugs but way only at idle, I would have thought a plug or lead would play up all the time. For info I only ever run 98 fuel and yes I can also set my watch to it every few seconds.