Q: Today my car made a loud knocking noise and when I press on the gas pedal, the car doesn't accelerate right away but when it does it makes a knocking noise.

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The knocking noise just started today and is quite loud when car is started up and driven. What should I do to fix this issue?

My car has 356000 miles.
My car has an automatic transmission.

The noise that you are hearing could be one of the rod bearings are knocking in the engine or the flex plate could have a loose bolt making the torque converter bounce around. I recommend seeking out a professional, such as one from Your Mechanic, to help you diagnose your knocking noise.

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