OK i Have a '00 Galant with an '03 engine. Since i changed the engine i would randomly have these moments where while driving, the car would shake vigorously for at least 3sec and then continue as normal, i thought it was a wheel but then i got them checked out and was told there was nothing wrong. i noticed that sometimes it would idol harder than normal, but anytime i bring it to my friend (a mechanic) to find out whats going on he test drives it, and nothing happens. now if it would happen at a certain speed or when braking i would be able to give some type of reason or test scenario to help find out whats wrong but its random. some days it doesn't do it at all. i even took it to another mechanic to see if he saw anything wrong and still nothing. no check engine light comes on before or after and no stalling. i cannot figure out what it is. I went online to see if i can find any similar situations and nothing.

the only way i can describe the shaking is, well everyone I'm sure has gone to a super market . if you ever got the cart with that one messed up wheel that shakes and makes the whole cart Vibe when you walk and has that annoying thumping noise then multiply that x12 and bring the thought back to a car. but as like i was told my wheels are fine.

so right now im running on Paranoia or straight up delusional. I refuse to believe im either of those lol. so does anyone know what the hell im talking bout or do i have to choose one of those titles to stick with? lmao I NEED HELP...

 

thanks for the reply, greatly appreciated.