Flex33

my 99 gs 400 was recently hit from the from , radiator support was pushed back, but once everything was pulled back into form i now have a noticeable vibration and rough running engine, the maf assembly is fine,all hoses are attached and fine, i havent looked underneath the car, but i did put it on a comp and it came up with no codes, do u think broken motor mounts would possibly be the cause of this vibration feeling...

FrankT

Yep, broken motor mount...worth checking

ramo99

Because you had a front hit damage, your front is not stable as before.
If your motor mount is good, then you might have to replace the radiator support that you refix

rysbrnr

Also, once you've checked the motor mounts and they check out to be fine, I'd make sure the car is actually running like it's supposed to. Make sure every cylinder is firing and might as well check ignition timing while you're at it. A slight misfire will cause stumbling and hesitation. Misfire at idle can and will cause a vibrating or shaking sensation in the mounts are good.

Check the mounts first as other have said and keep us posted. The collision could be the very reason for this.

Flex33

thanks for the suggestions, i checked the motor mounts and they are fine, i replaced the radiator support, now i will check the cylinders, my father thinks its in the cylinders also, i will keep u posted