My serpentine belt and pulleys were replaced. That didn't solve the problem. I have a loud churning light knocking noise coming from under my hood.
My car has 124000 miles.
My car has an automatic transmission.
Hi there. Remove the serpentine belt and start the engine. If the noise is still present then its not the engine accessories. Then the noise could be a lifter tap that is either a lifter that is stuck or clogged from getting oil into it. If you are having an issue with the lifter tapping, then drain out some engine oil and add 1 quart of ATF Type F to the engine and run the engine at 3,000 rpm for 15 minutes. Then drain out the engine oil and change the filter. Fill up the engine with your engine oil that is normally used and start the engine up. See if the tapping noise has disappeared. If the noise is still there, then a lifter may need to be replaced. If you plan on replacing the lifter, I recommend replacing all of the lifters. If you need further assistance with a loud tapping noise when the engine is started, then seek out a professional, such as one from Your Mechanic, to help you.
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