My engine is shocking and knocking when I start it. It still drives. What is wrong.
My car has 240000 miles.
My car has an automatic transmission.
Rough idle/operation could be due to a bad tank of gasoline, dirty fuel injectors, incorrect idle speed, exhaust restrictions, vacuum leaks, incorrectly installed or damaged spark plugs, a defective or clogged fuel pump or fuel filter, failing electrical components such as the ignition control module, plug wires, coils, and spark plugs, a defective airflow sensor, dirty oxygen sensors and other causes. To get the underlying issue identified, I would recommend that you request a rough operation/rough idle diagnostic and the responding certified mechanic will perform the required diagnostic steps to get this resolved. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.