Last Updated on May 6, 2021 by Joe Regan
Can you push-start an automatic car? Some drivers say you can push start an automatic car, and some say you can’t. But in theory, can an automatic car be jump-started on a dead or flat battery?
It is not possible to push-start an automatic car because automatic transmission cars have open clutches that stop them from being able to push start, unlike the manual versions that you can close its clutches that in turn, cranks the engine and get it running. One of the best possible ways to crank an automatic transmission engine is to jump-start it.
There are several other options and ways on how to start an automatic transmission car with a dead battery and get it running. But let’s look at an in-depth answer on if it is possible to push-start an automatic car.
Can You Push-Start an Automatic Car?
The best answer regarding whether you can push start an automatic car is “No.” How a typical automatic transmission vehicle is designed does not encourage push-starting. You can push start a manual car instead because manual transmission allows you to engage the gear. Typically, you select the first gear while holding down the clutch pedal, allowing the vehicle to roll as though in neutral.
While the car is running between 10-20 mph, you release the clutch pedal, which engages the motor to transmission connections. If the car is in gear, the transmission spins because the car is rolling; thus, rotating the crankshaft. This action is achieved when the gear turns the flywheel by the starter, resulting in spinning the motor.
However, in an automatic transmission, you can’t engage the gear, then disconnect it from the motor for it to roll like the manual transmission clutch, which is a huge difference between an automatic transmission and manual transmission.
Some drivers put the vehicle in neutral and slam the gear while the car is rolling; do not try this. Others also achieve the feat with a traditional torque converter. Unfortunately, it is not an intelligent thing to do, and you’re discouraged from it.
But, if you are tempted to push-start your automatic car, get another vehicle to push it. It’s unlikely that you can push it to a 30mph rolling speed to trigger the engine. Another vehicle pushing yours may achieve the feat.
Meanwhile, when the tranny fluid pump does not drive, you can’t obtain TC proper fill. Nonetheless, you might have enough fluid residues in the TC, the difference between a decent transmission fluid service and the regular service.
Besides, some years ago, older model vehicle owners would remove the shield, rotate the TC, pull the plug, and drain the converter.
You could push start automatic transmission vehicles through about 1958 to mid-1960s. Some of the 90s motors you could push start include Chevy Powerglide, GM’s Hydramatic, Ford’s Cruise-O-Matic, etc.
Why Can’t You Push-Start an Automatic Car?
A typical auto transmission vehicle is not in gear; thus, pushing it can’t fire the engine. Besides, you can’t push start a manual transmission without engaging the clutch.
Automatic cars feature special fluid clutches that prevent power delivery when the components/parts rotate slowly. It is this feature that allows an auto car to stop while the engine turns over gently. In this regard, pushing an automatic car at walking or running speed prevents the wheels from transmitting enough power for the engine to start.
Your automatic transmission requires hydraulic pressure to engage the clutch. And the input shaft drives a pump that supplies pressure turned by the engine.
In some vehicle transmissions, the output shaft drives the pump, but such vehicles are rare. You should find it in older Volvos, though.
Meanwhile, some automatic transmissions were designed to let you push start a car. A typical off-road vehicle would push start; however, you would have modified it extensively, plus adding pumps or external oil accumulators.
Ways to Start an Automatic Transmission Car without Push-Starting.
Spin the Alternator
Instead of trying to push-start your automatic transmission car, you can start an automatic car by spinning the alternator, but your car battery must have some juice left. First, remove the fan belt. Next, you need an energy source; you can connect a motorcycle rear wheel to rotate the alternator fast and long enough to start charging the battery.
Since you may not roll an automatic transmission car up to 30mph, you can tow it faster. You’d need a tow van or any vehicle that can tow it to spin the transmission up to about 30-35 mph, depending on your vehicle model.
But if you find a small vehicle that can tow 3,000 lbs or the weight of your car, you can get your vehicle running. Or, you can use the available car to jump-start your battery rather than ruin your transmission by tow-starting.
Since you can’t push-start an automatic car, a better option would be to jump-start the car. You can jump-start an automatic vehicle; it works by using the battery from another vehicle to boost-start your car by charging the battery. Jump starting an automatic car with another car is similar to jump-starting a manual transmission using jumper cables.
Make sure to connect the red to the battery terminals and the black to the negative battery terminals. You will then connect the other black to a grounded system like the engine block of the vehicle you’re using for the jump start.
The reason for connecting the black ends to the negative terminals is that batteries give off hydrogen gas, presenting an opportunity for a spark that can ignite, causing battery explosion.
Finally, start the engine of the vehicle that has a good battery and allow it to idle, and charge the battery for a few minutes. Meanwhile, how long it takes your car battery to charge depends on the cable quality and level of the battery before a charge.
If you are not careful when jumpstarting, you may degrade or damage your car computer. A model like the Mercedes Benz could result in severe computer damages, demanding 10,000+ in repair cost.
Coast Downhill in Neutral
You can put an auto transmission car in neutral and coast it downhill to start. While the car is rolling down the hill at about 60 km/h, you would turn the ignition on to restart the engine and put the transmission in D.
Push starting an automatic transmission car feel like what would work, but it will not, especially if you own a modern vehicle. Your best bet is to fix the starter or battery.
Also, if your car won’t start for any reason, excluding a drained or dead battery, a push start won’t work. Inform a technician or have your vehicle towed for service.