Hi all. So I have an 07 Accent with 84k miles on it that heavily vibrates/shakes at idle. More so after the car has been driven. I’m talking like I can see things in my car vibrating and feel it under my butt. It also seems like the car has mediocre mid range power (I’m talking like 40-50 mph). Engine does seem a bit loud when accelerating also sounds a bit squeaky from the engine bay. So far I’ve;

changed to good quality spark plugs
added fuel injector cleaner (sea foam)
new coil packs
oil change with OEM filter and added some Lucas stabilizer
cleaned the PVC valve
lightly cleaned the throttle body (could probably go more in depth with it)


Im not sure where else I should look. I have no codes, no stalling, car runs well besides the shaking and noises. Im a wannabe DIY mechanic so I’d like to try to fix it myself if possible. I don’t think it’s motor mounts because I’ve put it in neutral and the vibration is pretty much the same.

 

What you might have done was to look carefully at each spark you removed and if one or more were black with carbon or wet with fuel or oil that could have tipped you off to which cyl(s) might be misfiring. Here again we are , assuming, it is a misfire condition which most folks describe as a vibration.
Is the check engine light coming on?
If neither applies here , you would have to isolate which cyls are causing the problem.

 

Rather than think it is not the motor mounts, how about actually looking at them??

 

If you have the hood open to see the engine , observing from the side of the vehicle, someone in the driver's seat , engine running, foot brake applied and place the trans in drive and apply a little throttle. If the engine moves a lot the mount(s) need to be replaced. Mounts usually last a fairly long time , except , jack rabbit starts and heavy feet on the accelerator pedal can destroy motor mounts pretty quickly. if that is the problem.