my car shakes when idling but when accelerating it stops.I recently changed the spark plugs but I have the same issue.Anyone have an idea oof what can be wrong?

  • So does it make a weird clunking noise right as you accelerate? As you give it gas to accelerate I mean? Almost like it's going to stall? If so have you checked your intake system. You may have a vacuum leak. Or since you just changed your spark plugs, did you make 100% sure they are gapped to manufactures specs? Oct 15, 2020 at 5:56
  • Is it an automatic or manual transmission? Does it only do it in neutral, park or drive? Clutch pressed or released? In gear or in neutral?
    – user60481
    Oct 15, 2020 at 6:05
  • Hi Rasahrd, Welcome to the Mechanics Stack Exchange. We need some more information here for answering this question. Could you provide details about the year and model of your car, whether it is automatic, manual, and whether you get any check engine lights. Typically, an issue like a shake at idle occurs if the car is idling too low, or has issues with engine mounting. What RPM does your car stay at when idling?
    – H. Daun
    Oct 19, 2020 at 4:27
  • 1
    Does your engine have balancer shafts? Have you recently done a belt service? If so are you sure you got the balancer shaft timing right? I bet you can guess why I'm asking. Oct 28, 2020 at 23:24

1 Answer 1


Typical problems causing excessive vibrations when idling:

  • worn out engine suspension. The engine is mounted on rubber pads, which wear out and need to be replaced eventually.
  • damaged dual-mass flywheel (applicable to some modern engines)

Typical problems causing uneven running, which can be also be described as "shaking/vibration"

  • damaged or dirty throttle/throttle sensor/idle speed nozzle/anything that's involved in regulating idle rpm
  • damaged component of ignition system: cables, coils, distributor, etc (sparkplugs too, but you've already replaced them)

Bottom line: IMHO you've already done what was possible to do without professional help - replaced plugs. You can visually inspect rubber pads for damage, that is if they're accessible. Fixing any of the above usually requires professional workshop. If the problem is uneven running, you can try checking out the throttle, but in modern engine there is more risk you accidentally knock something out of alignment than to actually fix the problem.


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