i had all my motor mounts replaced and 2 trans mounts. but in drive ONLY and ONLY at idle there is a VERY bad vibration what the heck could it be??
My car has an automatic transmission.
Hello. Most of the time if the mounts are new and it still runs like this it is because you either have a vacuum leak or the idle is too low. A dirty throttle body or a failing idle control valve will cause this to occur. I would check these first. It can also be a failing valve seat inside of the engine so the compression may need to be checked also. If you are looking to have this problem looked at, consider YourMechanic, as a certified mechanic can come to you to [diagnose why it idles rough] https://www.yourmechanic.com/services/car-idle-is-rough-inspection