car shaking

2003 BUICK LESABRE
187,900 MILES • 6 CYL • FWD • AUTOMATIC
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TINA HARRIS
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  • 3 POSTS
I the changed the plugs, wires, and coil pack. I checked engine light flashing on and off. Reading a PO300 code, Random misfire code?
May 17, 2016 at 9:40 AM
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JOHNNYT73
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okay. Was it doing the misfiring before you changed the parts?
May 17, 2016 at 10:03 AM
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TINA HARRIS
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No, it was running fine. Then one morning it heard a squeaking sound and it started to shake and the check engine light started flashing.
May 17, 2016 at 12:50 PM
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TINA HARRIS
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I am sorry, yes it was misfiring before we changed the parts.
May 17, 2016 at 12:51 PM
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STRAILER
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Hi Tina,

Does it misfire under power if so, then I would check the compression to see if all cylinders are okay it could be an injector,

here are two links that can help you


https://www.2carpros.com/articles/how-to-test-engine-compression

and

https://www.2carpros.com/articles/how-to-test-a-fuel-injector


let me know what you find

Best, Ken

May 21, 2016 at 1:10 PM