Q: Engine is knocking loudly and has a weak acceleration.

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When we left this morning, the car ran normally. We stopped at the gas station and as we were pulling in we started to hear a slight knocking. As we pulled further in, the knocking became louder. We checked the oil level and noticed it was low. We hadn't kept a close check on it recently as we should have. We filled the oil to the correct level. The car engine continued to knock and when I tried driving it home I noticed a huge problem when trying to accelerate. It moved very slowly at first and finally kicked in and gained a little more speed. The car has no problem starting but continues to run with the loud knocking. The car is a 2005 Ford Five Hundred. I've owned the car for about a year and a half and was told it had a new engine put in just before I got it. The knocking sounds like it's coming from the top of the engine. My car has 157000 miles.
My car has an automatic transmission. *Update: We drained the oil and there were no metal shavings in the oil

You may have damaged the engine bearings by running it low on oil. I would suggest not driving it until you have an engine mechanic listen to and diagnose where the noise is coming from. If the noise is up top then you may have jumped timing or the cam is damaged. If the noise is in the lower engine, then the bearings could have failed. If you need help, a technician from YourMechanic can inspect the noise and verify the fault so that correct repairs can be made.

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