l have a Chrysler PT Cruiser with very high miledge. My vehicle is starting to sound a little rough when idleing, l have carried it in for a tune up and it still sounds the same. Does anyone else have this problem out of their Cruisers???

Have you tried redlining it a couple of times? Sometimes carbon deposits build up on the spark plug and such. Revving the engine every once in a while will clean that off. A lot of people baby their car and never rev it to redline. Do it when the car is warm btw. It might help.

My '96 Neon was idling rough a while back.turned out to be the EGR valve. The replacement part was $120.00, so l just took it off & cleaned it out. The problem has been completely cleared up.

The other guy is correct.getting on the highway & opening up the engine (by that l mean redlining it) may clean out a lot of things, including the EGR valve. It is not guaranteed to work, but it may. When u do that just make sure to rev the engine until it redlines then let it shift ( l am sure u knew that already, but just in case).

Try cleaning the Idle Air Control motor IAC this controls the amount of air entering at idle. It mounts in the throttle body with two screws probably, it should be round, remove clean with scotch-brite and carb cleaner , be sure to spray down in shaft to brake up carbon there. also clean mating surface inside throttlebody

also pullyour spark plug wires and inspect the valve cover gaskets leak sometimes coating the wires with oil causing misfires