How does pushing a car that won’t start help start it?
In: 1758
It only works if the thing that is preventing it from starting is a dead starter motor. The rest of the electrics need to be in order. The following is for a manual car.
When you turn the key/ press the start button, an electric motor cranks the engine and initiates the firing sequence of the engine. Once that takes hold, the motor disengages and the engine keeps itself alive via the sequential piston motion. This motion is transferred to the wheels via the transmission, which is linked to the engine via the clutch.
When you push a dead car, and the clutch is engaged, the opposite happens. The wheels can turn the engine. So what is happening is you are in effect doing what the starter motor does to initiate the piston firing. Only a fully engaged clutch at standstill is incredibly resistant to motion thanks to the gearing. This is why when doing a roll start, you would have the gear in neutral (wheels and engine disconnected), push the car without the resistance of the engine, then pop the clutch once you’ve built up enough momentum to connect the engine and wheels, causing the wheels to turn the engine enough to start the firing sequence.
I don’t think it works on automatics, but I may be wrong about that.
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