A 2000 Toyota Celica GTS 225k miles engine makes a mild rumbling/grumbling rough sound when accelerating slowly from a stop in drive or reverse only in the 800-1300 RPM band. Does not occur when in Park. Not sure what could be causing this mystery.
Already changed (with OEM Toyota parts) Exhaust gaskets, Plugs, all 4 motor mounts
Sounds almost like something in the engine is loose, pistons, value chatter, I am lost for an answer.
Hopefully someone has a thought, Thanks!
If you've never changed them, the problem might be one or more of the motor mounts. When one is worn out (especially ones which control the torque of the engine - like a dog bone type), it will start making strange noises when in the lower part of the RPM band from a stop. This can hold especially true if you are not really hearing it when up to speed. You can also feel it jerk a bit while taking off from a stop or hear it clunk (or dull thunk) when stopping hard.
