Engine "kick" at idle
 

I bought my 2000 2.4L at just shy of 148,000, and wound up putting a used Grand Am engine in it (with 80k miles?) because, 100 miles later, a valve lifter chipped and started making a horrible racket. The engine had various other issues from poor maintenance that made it not worth rebuilding. :glare:

Anyway, I've been driving on the "new" engine for the past couple of months, and I've noticed that sometimes while idling at a light or something, the car will "kick;" I can feel the slight bump in my seat and see the hood of the car shake up a bit more than normal, and it'll do this without a particular pattern every few seconds until I take off again.

Is this anything I should be worried about/is there anything I can inspect to reassure myself I'm not about to buy yet another engine (or car)?

just sounds like a spark issue to me. possible need new plugs or coil pack thing

vacuum leak i had the same problem when i first put the 2.3 manifold on