"Shudder" sound like a clutch issue If its been a long time since the clutch has been replaced that may be the problem. A way to check engine mounts is to open the hood, sit in the drivers seat and find an angle to see the engine. Then push in the clutch, put your heel of the other foot the brake, reach over with your toe and give it some gas, slowly release the clutch, if the engine looks like it is trying to jump out of the engine compartment, the mounts are broke. If there is no abnormal movement they should be good. also with a clutch a new remanufactured clutch can tend to cause "shudder" for that reason I always spend the extra and get a new one.