Vibration/rough idle after driving around fifty minutes

Hi,

This could be a number of things. If it past PA inspection then that just means that the check engine light was not currently on. Clearly this sounds like a misfire so we need to go down that path first. If it only does it after some run time, we can assume it is because they are getting hot.

I would suggest starting with monitoring live data when this happens. I am hoping you have the ability to look at this because when it is running rough we need to see what the short term fuel trims are doing.

I am suspecting that we will find one or multiple cylinders starting to misfire. If we do we know where to start. However, the fuel trims will tell us if that is happening and then we can look at each cylinder to determine which one is the issue. If you have a misfire starting, then it could be the coils starting to go back or possibly the MAP sensor if it is moving around to different cylinders. I would not recommend replacing the coils because there are 8 of them and that is pretty costly if we don't know that is the issue.

Let me know what you find and we can go from there.

The car can't have bad coils in a 43,000 mile hemi engine. And the problem goes away as soon as i restart the Aspen. I would think its electrical problem.

I am starting to believe it is an ECM sensor going bad. Which would explain how the problem comes and goes. However, I would think there would be a check engine light if this was the problem. Not sure....

Okay, but a coil absolutely can go bad in 43,000 miles plus if this is original they are over 12 years old so while it would be low mileage for them to fail it would not be surprising.

I agree that a sensor input to the PCM is most likely your issue. We need to monitor the MAP, ECT, O2 sensors, and IAT. These would be the most likely cause of the issue.