Co-Authored By:
Just so, can you drive on a misfiring cylinder?
Driving with a misfiring cylinder is not safe under any condition. It can cause severe damage to your car's engine and thus most of the people advise not to drive with this problem.
Subsequently, question is, what happens if spark plug is loose?
Under-torquing a spark plug can be just as fatal as over-torquing a spark plug. Under-torquing is a “don't” because a loose or improperly seated spark plug can overheat which can cause a pre-ignition or a misfire condition. Over-torquing a spark plug is also a “don't” because the insulator can be cracked.
It depends on the cause. For example, if the misfire is caused by a bad on-plug ignition coil, which is quite common on many newer cars, the repair might involve replacing a bad coil and all the spark plugs. This could cost $300-$400 for a 4-cylinder engine or $450-$700 for a V6.