QuestionQUESTION: The past two months I have had problems with an intermittent stall during idle. It will sometimes run for a week with no problems. I've cleaned the throttle body, exchanged the IAC, replaced the plugs and wires, done a thorough check for vacuum leaks, tested/verified the EGR is functioning and closing off correctly, cleaned the camshaft position sensor and still I have this problem. It doesn't seem to matter if it's hot or cold, (motor and ambient temp)dry or wet, it will stall randomly. A couple times it would start and die immediately, but most times its when it is decelerating like to a stop sign, or idling in the driveway. It acts like the IAC can't keep up with load changes for the motor. (AC coming on/off, shifting into gear, radiator fans cycling) Lately it has started "hunting" for the correct RPM at idle and seems to rev up and slow down, many times overcompensating until it will stall out with too little RPM. There are NO CODES, and the "Check Engine" light has never come on. (Except when doing the fault code check through the ignition switch) I had the local Advance Auto put their OBDII on it and double check, but no codes stored. Please HELP!! Any suggestions will be appreciated.
ANSWER: Hi Paul,
My favorite candidate is the EGR valve, but you seem to have covered that one, though it might be fruitful to check while the instability/stall is occuring to view the position of the stem's slot. That is about the only component that isn't well under the view of the pcm. I can't suggest anything other than to keep checking for codes with the key. And be sure to let me know how it gets resolved so I can share it with others.
Roland
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QUESTION: Roland,
I went to a Chrysler "pay for an answer" site and I was told, "Most commonly this is due to a faulty camshaft crankshaft position sensor, if the timing belt gets too loose the sensors will go out of sync cause the same problem." I have read a lot of posts on a lot of sites for stalling problems and this was the first time that anything like this came up. If it were either of the sensors, I would think they should show up in the fault codes, but a too loose (very warn) timing belt? What is your opinion?
ANSWER: I have heard of that when the cam sensor is mounted on the timing cover (2.0/2.4L 4 cyl engines) and views a cam shaft sprocket, but not for the distributor-located sensor of the 2.5L V-6. In the former situation people have noticed that the engine will run if the cam sensor is disconnected, but stall when not! But I would question it for your engine.
There is no easy way to disconnect the cam sensor as its wires are bound up with the spark coil driver in the 6-wire plug so we can't test the theory. Have you inspected the belt and how far has it gone? To check the timing would involve a good bit of work unfortunately unless you found tdc by probing the #1 piston through the spark plug hole and even then that would have some error associated with the measurement.
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QUESTION: Roland,
Maybe something got missed earlier. I do have the 4 cyl 2.4 liter engine. In my first question, I mentioned I cleaned the cam sensor. It's located above the throttle body on what I guess could be described as the timing cover. So I can disconnect it and in theory the engine will run without the stalling? I should get a fault code for the cam sensor, but for testing purposes can it be run that way for a day or two?
AnswerHi Paul,
No, I assumed it was the 2.5L. Well, give it a try and see whether it will run or not. It may be less efficient fuel-wise/power-wise if it works at all. I now picture your cam sensor on the rear of the engine.
Maybe a better idea would be to check that the two cams are at least well aligned by removing the top timing cover (two screws) and flexing it enough to check to see if, when you rotate it by hand around to tdc of the #1 cylinder, the lines on the two cam sprocket are directly oppositie to oneanother. That might, if good, suggest that the timing belt stretch theory is plausible.
Roland
