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Q: As my car warms up it starts to make a knocking noise. Then stalls when I stop.

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When it starts while cold it starts fine. As it warms up it has a knocking sound and starts to shake. When I stop at a light or stop sign it will stall and went start I until it's cooled down. I replaced the spark plugs and thermostat do it doesn't over heat.

My car has 181900 miles.
My car has an automatic transmission.

A: Hello. Unfortunately these are typically si...

Hello. Unfortunately these are typically signs of a more serious issue. Your engine may have thrown a rod. Which means the connecting rod that hold the piston in place has broken off. The only repair is to rebuild or replace the engine. You will want to have the vehicle inspected as soon as possible. There are other possible causes for the engine knocking, but they typically don’t cause a violent shaking or a stalling situation. They would include the lifters, injectors, bad or contaminated oil, and even a bad oil filter or valve. When oil is a factor, it lubricates the engine better when cold. The oil heats up and becomes thinner and has less lubricating properties. Only further testing and inspection is going to be able to tell what is causing the noise and how to take appropriate action.

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