Chrysler Repair: Rough Idle for my 2001 Sebring Coupe, oil filler cap, vacuum hoses

Question
Hi Roland,

I've read a lot of your answers and I can tell you really know your stuff! I was hoping you could help me with my problem. Recently my 2001 Sebring coupe with 3.0L engine has been acting up. the check engine light turns on for a few days then goes off. the second problem is while the check engine light is on my car runs and idles really rough. It is most noticeable when parked or when coming to a stop. (It feels as if the car is hesitating or jerking). I was told i need to reflash the computer and possibly replace the spark plugs. But I don't think that will fix it. Any ideas?

Thanks,
James

Answer
Hi James,
Chances are the rough idle is caused by an egr valve that is sticking slightly ajar.
The egr system is in a small pipe that connects the front (side of the engine) exhaust manifold to the intake manifold and it runs by the oil filler cap.  The valve is bolted into that pipe and controls the exhaust gas amounts that return to the intake.  The valve has to open and close firmly and quickly or the engine will not operate well due to a mixture of fuel and air that will not allow the engine to accelerate or idle well, if the valve is not where it is supposed to be. Often it will get sticky and fail to close all the way, for example which it has to do at idle and when stepping on the gas toward full open throttle. It is controlled by a vacuum operated and electrical control solenoid mounted near by, and those vacuum hoses should be examined to make sure there is no cracked, leaking, or disconnected hose fittings. There is a vacuum operated round fitting on the top of the egr valve, and also a vacuum line going to an electrically operated solenoid closer to the engine, nearer the throttle body. Look under the round fitting (which is mounted on a saddle with openings for access to view) on the top of the valve where you will see a rod with a slot in it which is the valve stem. Take a straight blade screwdriver, insert it in the slot, and then use the driver to lever the valve up (against spring pressure) and let it return to see if it is dropping back all the way down due to spring's action and closing positively to a firm closed position. Spray WD-40 or other penetrating lubricant on the valve stem to loosen it up in that in and out motion. Check to make sure the vacuum lines are all attached and not cracked. Then warm up the engine and observe the slot to see if it goes up when you rev the engine to 2500 rpm and then drops back down fully, closing the valve, when you let the engine go back to idle rpm. Make sure that the fully down position is really down because if it is not fully closing when you let go of the accelerator and coast that will cause the engine to stall. It may be that to get it to close you'll have to unbolt it and clean out the gas flow passage past the valve, due to buildup of exhaust fumes in the valve as sticky crud deposit around the internal valve.
You could also check for fault codes stored in the engine controller using the ignition key:"on-off-on-off-on and leave on" doing that in 5 seconds or less elapsed time. Then watch the odometer window to see the mileage reading change to show a 4-digit number preceded by a P. Tell me the number and we'll go from there.
Roland