Chrysler Repair: Dieseling after shut off: 90, combustion chambers, mixture problem

Question
1990 chrysler motor continuously runs after turning off the ignition for a few seconds.  In addition, there is a loud noise under the hood after hitting a bump. If it is the fly wheel, how can it be repaired.  

Answer
Hi Rushan,
I doubt it has anything to do with the flywheel. But you didn't tell me the model, engine, or type of transmission so it is a little more difficult to suggest specifically what to do. When the engine runs on it usually is due to what is called "dieseling" which means you get combustion even though there is no spark. It is usually due to a build-up of carbon in the combustion chambers which is heated so hot as to cause the residual gasoline injected to fire spontaneously. You might have a mixture problem too. So what I would suggest is the most prudent approach now would be to check for fault codes stored in the engine controller memory. Use your ignition key to get these codes. Give it a try:
"On-off-on-off-on and leave on" doing that in 5 seconds or less elapsed time. Then watch for the check engine light which remains illuminated to begin to flash, pause, flash, etc.  Count the number of flashes before each pause, then repeat that to verify that you have the numbers accurately. Then group them in pairs in the order they readout to form 2-digit numbers that are the fault codes. Tell me those numbers. The last number is always 55 because that code means "end of readout" You can get a code list at www.allpar.com/fix/codes.html or write back and we can give you some ideas of what might be wrong to cause it to diesel.
You can also buy some combustion chamber "cleaner" that is added to the gas tank and see if that helps out after using one container.
The loud noise from a bump is more likely something to do with the suspension, such as a loose sway bar or other bolt. I would recommend going to a front end alignment shop to have them look for anything on the front that is loose. It might also be engine mounting block that is worn out. Those sorts of things can be noticed pretty easily at such a shop. I doubt it is related to the mechanical aspects of the engine.