M20 engine vibration at 1200 rpm

I am trying to figure out why I have an engine vibration that is exacerbated when under load at around 1200 rpm, but is there, although less pronounced, even when the motor is not under load. I have an M20 engine that just had its timing belt and water pump changed. I thought maybe it was worn out motor and transmission mounts so I changed them too but the vibration still exists. We tore the front of the engine down and removed belts and pulleys to try and isolate the vibration, but it still persists. We are at a loss as to what is causing this. The harmonic balancer is fine. Anyone have an idea what this could be? i

Originally Posted by alamers

I am trying to figure out why I have an engine vibration that is exacerbated when under load at around 1200 rpm, but is there, although less pronounced, even when the motor is not under load. I have an M20 engine that just had its timing belt and water pump changed. I thought maybe it was worn out motor and transmission mounts so I changed them too but the vibration still exists. We tore the front of the engine down and removed belts and pulleys to try and isolate the vibration, but it still persists. We are at a loss as to what is causing this. The harmonic balancer is fine. Anyone have an idea what this could be? i

Flex disc, CSB, or a bad driveshaft, possibly?

I will take a look at that perhaps. It started when my mechanic changed the timing belt and water pump.

Nope its not the drive train because it vibrates while still in Park. It is an automatic. Perhaps it is the torque converter? Has anyone had experience with this?

Originally Posted by alamers

Nope its not the drive train because it vibrates while still in Park. It is an automatic. Perhaps it is the torque converter? Has anyone had experience with this?

Are all of the exhaust mounts and hangers in tact and secure?

Originally Posted by alamers

Nope its not the drive train because it vibrates while still in Park. It is an automatic. Perhaps it is the torque converter? Has anyone had experience with this?

Cam to crank timing didn't get off a tooth?

Potential damage to wires like CPS or the CPS itself?


Do you have the time to go back to your mechanic and explain that this was noticed after the work? Hopefully they are nice and can check it out without cost.

Originally Posted by syntrix

Cam to crank timing didn't get off a tooth?

Potential damage to wires like CPS or the CPS itself?


Do you have the time to go back to your mechanic and explain that this was noticed after the work? Hopefully they are nice and can check it out without cost.

+1 if they messed something up they should fix it free of cost considering you paid them to do a job and messed up something up

mine has the same issue, what was the resolve?? This one is driving me crazy

Is it just vibration? Are you having a low idle? Like syntrix said CPS or possibly other sensors not being plugged in. But if you cant figure it out +1 on taking it back to the shop you had do the work.

I believe it is my idle too low