Explain why cars with manual transmission able to start when you push the car while automatic transmission can

Question

Explain why cars with manual transmission able to start when you push the car while automatic transmission cannot start even when you push the car?

Answer 1

the starter of a car turns the engine at a rate of speed that enables combustion to the cylinders to fire in sequence, allowing the engine to start.
when you push a car with a stick shift and "pop" the clutch, you transfer the motion of the tires to the engine, duplicating the torque of a starter.

Answer 2

You can push start a car with a manual trans because when you have the vehicle in gear and let off of the clutch you in turn ,turn the engine over via the transmission because the trans in now engaged to the engine via the clutch and the wheels are turning which is hooked the the drive shaft or CV axles which are hooked to the transmission. By the Way you have to have the key on.
The reason you can not do it with an automatic transmission is because there is no rear fluid pump in automatic transmissions anymore. With no rear fluid pump, you do not have sufficient fluid flow thru the transmission to cause the torque convertor to lock the engine to the transmission to turn the engine over and help it start up. Make sense.

Answer 3

With a manual (stick shift) you are directally engaging the engine and transmission to each other through the clutch. So if the wheels are turning and you have the vehicle in gear, the engine will also turn. If the engine turns, the the alternator and all other systems will turn and work also. Generally you need to be going about 8 mph or faster for a "bump start" to work.

With a automatic transmition, you have a torque converter.

When the engine is running, a fan like blade is turning in the converter. This in turn moves transmition fluid. As the transmition fluid moves past another set of fan like blades connected to the transmition, the transmition then turns.

An automatic transmition vehicle can be "bump started", but you need to be going about 30 mph to do it. Pulling another car at those speeds is very dangerous.

Hope this helps.

Answer 4

A manual transmission has gears that are phusically engaged with each other than connect the rear wheels to the motor. (simplified)
When you push the car the wheels turns the gears which turns the motor and YOU become the starter and it starts.

A automatic transsmission uses liquid pumped by a pump to turn the gears, there is no physical connection unless the ENGINE IS ALREADY RUNNING. so you can push all you want but the engine is not being turned so it won't start.

Many years ago Oldsmobile made a transmission that had a "reverse pump" It was the only car I know of that COULD be push started.

Answer 5

Automatic transmission can only engage when there is a oil pressure, because it's operated by hydraulic pressure. The oil pump that makes that pressure is operated by the engine, meaning when the engine is off, there is no hydraulic pressure to engage the automatic transmission.
In manual it's just straight set of gears and a clutch.

Answer 6

when you push a car w/ a manual tranny and then pop the clutch you're actually doing the work of the starter. i.e., you're turning the engine over to get it running. it's like old cars that you had to hand crank to get started.
you can't do that with an automatic tranny because you cannot control the clutch. the clutch is automatic as well. it's controlled by the gear shift and the rpm of the engine. so you can't pop the clutch like in a manual tranny.

Answer 7

well actually you can start an automatic by bump start you need to get it to around 35 mph and it will start i have done this many times before any good mechanic will tell you this also