A flywheel on an automobile is used to balance the vibration of the engine and is attached to the crankshaft. The flywheel on a manual transmission vehicle doubles as a balancing device for the engine and the clutch system. A automatic automobile has a flywheel which is attached to the torque converter. Various problems arise when the flywheel is loose.
Excessive Engine Vibration
The engine vibrates from the combustion of the pistons pressing down on the crankshaft. To limit this vibration, a flywheel is attached to the crankshaft, which balances out the vibrating engine. Once the flywheel loosens on the crankshaft, the engine has excessive vibration which can shake the entire vehicle. This vibration can cause damage to the motor mounts, transmission mounts and shake other engine components loose. The vehicle operator will find that steering the automobile becomes difficult. The flywheel needs to be tightened or replaced once it becomes loose.
Manual transmissions have the flywheel as part of the clutch system and the engine system, which is commonly referred to as a dual flywheel. Once the flywheel becomes loose, the clutch will begin to slip when it is engaged. The operator will hear a grinding noise when the gears are shifted because the clutch is not holding the transmission in a neutral position. This loose flywheel can cause the transmission to wear the internal gears and the automobile can loose one or more gears because of damage. The flywheel needs to be inspected to determine whether the bolts need to be tightened or the entire flywheel needs to be replaced.
Car Will Not Start
The automobile will not start if the flywheel is loose. The operator will hear grinding noise or clacking noise once the engine ignition is turned. The ignition engages the starter motor which in turn engages the flywheel and cranks the engine. If the flywheel is loose on the crankshaft, the gears of the starter motor will only grab part of the flywheel gears or not grab the flywheel gears because of misalignment. The automobile will not start and once all other mechanical problems are determined to be in good condition, the operator needs to have the flywheel inspected to determine whether it is loose or missing gear teeth, which causes this starting problem.