possible due to Engine mounting problem or ECU is not responding properly.
Pls. contact to your mechanic ASAP.
Usman Ali
It is idling. This is hard for an engine to do smoothly.
Possibly due to engine mount
My guess would be to look at the motor mounts to see if they are loose or broken.
There are many reasons why your car might vibrate while it is idling. It could be running too hard for example.
When does it make a tapping noise? When your !) braking and turning wheel B) braking c) engine idling D) starting engine E) turning. I mean it just all depends....
It is likely that if it was during an idling condition or low rpms your EGR valve could be sticking open or faulty.
The power steering pump is working hard and the engine is only idling. It could be the harmonic balancer
A bad throttle position sensor, on your 1991 Saturn, will cause the engine to run rough when it is idling. The engine will run normally at higher speeds.
A car that is stopped with the engine running.
first check engine timing this is a major cause of vibration in a stationary vehicle, or non firing cylinder could be electrical or mechanical, then harmonic balancer, then look for broken engine mount.
Vibration at idle, especially with automatic transmission, is usually caused by engine idling to slow. Now, since there is no idle adjustment screw anymore you need to have the vehicle checked at your Toyota Dealer. Some vibration, even to that level is normal. IF IT HAPPENS IN THE PROCESS OF STOPPING, WHILE BRAKING, YOUR BRAKE ROTORS ARE LIKELY OUT OF ROUND.
is it a manual or automatic A. iT IS POSSIBLE YOUR MOTOR MOUNT OR TRANSMISSION MOUNT COULD BE LOOSE OR WORN OUT CHECK TO MAKE SURE. Your engine could just be idling hard.