Possibly due to engine mount
Because its a diesel!
take it to the shop!
Remove the belt from your diesel pump. Remove the diesel pump fuel lines. Remove the diesel pump retaining bolts. Reverse the process to install your new diesel pump.
Four forward, one reverse.
Diesel fuel and TiCl4 should not be mixed because TiCl4 is a highly reactive and corrosive compound that can react violently with organic materials such as diesel fuel, posing a serious safety risk. It is important to handle TiCl4 with caution and keep it separated from all organic materials.
sounds like the auto transmission has a fault
Before there can be an answer, need to know transmission type; 6 speed manual or 6 speed automatic? If its the manual, its the clutch takeup cable. The shifter should have a button or detent to push in order to move it into Reverse. Its most likely loose. If its the automatic, its most likely the brake sensor that must be engaged prior to shifting from Park. Driver must fully engage the foot brake prior to shifting from Park to Reverse and from Drive to Reverse. Most likely replacement of part will fix issue.
All engines will vibrate due to the rapidly moving parts. An engine should be securely mounted on fixtures that dampen vibration. Rubber mounts are an ideal example.
because the cars fuel type is diesel so it has a rattling due to the gigh fuel consumption
Most likely cause would be a failed U-joint.
some marine engines are reverse rotation, Also marine engines are made from anti corrosive materials, they are heavy duty and can tolarate vibrations of your ship.
You start by removing the fuel pump, installation is the reverse of removal.