car shaking

2003 BUICK LESABRE
187,900 MILES • 6 CYL • FWD • AUTOMATIC
Avatar
TINA HARRIS
  • MEMBER
  • 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
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.
Advertisement
Avatar
JOHNNYT73
  • AUTOMOTIVE REPAIR CONTRIBUTOR
  • 924 POSTS
okay. Was it doing the misfiring before you changed the parts?
May 17, 2016 at 10:03 AM
Advertisement
Avatar
TINA HARRIS
  • MEMBER
  • 3 POSTS
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
Avatar
TINA HARRIS
  • MEMBER
  • 3 POSTS
I am sorry, yes it was misfiring before we changed the parts.
May 17, 2016 at 12:51 PM
Avatar
STRAILER
  • AUTOMOTIVE REPAIR CONTRIBUTOR
  • 54,178 POSTS
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