Jetta heater water tank leaks, what is the most unfavorable to the engine? But it can start, the car has no strength and the speed is abnormal. Do you have any repair recommendations?

Hello, the worst thing is that the engine temperature is too high, which causes the piston to pull the cylinder and then needs to be overhauled. The dynamic difference is also related to the water temperature. Poor power is generally caused by carbon deposition in spark plugs, which is not conducive to ignition. If the throttle valve is too dirty, just clean it. It is suggested that the gasoline filter should be replaced if it is too dirty, so as not to affect normal driving.