ok so I have an 89 RS TBI 305 5 speed. When i drive I hear and feel a knocking sound even if coasting in neutral. I can feel it in the clutch pedal and gas pedal if that makes a diff. The faster the car goes the faster and harder the sound gets, when I come to a stop the sound decreases until i stop then the sound stops. I have talked to some people they say its not the engine because the sound stops when im not moving and the car is still on. does anyone know what may be the cause?

 

broken trans mount maybe?

 

how or where do I check and see if thats the problem?

 

Find out what the frequency of the noise is. Watch the rear tire and see if it is one thump per one tire revolution. If yes, it is in the rear end. If more often, like three thumps per one tire revolution, it is further ahead in the drive line. I had a thump, it was in the rear end. A roller bearing failed and a sliver of steel got on the ring gear. Also, it is only when going forward, or both directions?

 

I will check and see how many revolutions it is. I did notice that it doesnt happen in reverse.