Push Start a CVT?
 

On the way home tonight I saw a man struggling to push his old Honda Accord "down the road." Not really thinking that I was in the "country" part of Florida, I dutifully parked my Maxi on the side of a farm road and asked..."how far we going" as I started putting my back into helping him push his Accord down the road (Starter Failed and it was an automatic.) He said "just a bit down yonder" and I (you have to realize that I am originally from the Ozark Mountains of Missouri so I should know that yonder can mean miles....just lived in the city too long to realize what yonder meant anymore) began an arduous 1.3 mile exercise regimen!

It did get me thinking though...should I, for some unknown and unforeseen reason, be in a similar situation where AAA couldn't get to me (I do drive a LOT) I wonder how fast you would have to go to start the car with speed. As some of you may recall, back when my 09 was but a few months old, my service manager showed me how you could kill the ignition by pressing and holding the Start Button and that pressing it back to the "run" position would allow the car to "start." (Recall the Toyota run-away issues of old) At that time, we were going 55 on a rarely traveled road so I know it will start at 55...just wondering what the "minimum" speed would be for such a dire emergency?

Granted, such an exercise (pardon the pun) is more hypothetical at this point and not something I can see happening, but anyone know what the "minimum" speed would be?

you can't push start an automatic, this includes a cvt.. but what i think your saying is can you start and stop the engine while driving. the answer is yes, and you can do it an any speed. just like i can turn my key to off, coast, and turn it back on. in an automatic the transmission is completely disengaged from the road. it is not possible for the road speed to match an automatic transmission.

think about a bike. you can petal but as soon as you stop peddling, the bike will coast and the pedals will remain in the same position. you can start and stop peddling at whatever speed you want.<--- (turn your car on and off)

in a manual, the clutch is only disengages when your foot is depressed, because of this, you can push start it while in gear. the clutch is always disengaged when your are doing anything other than accelerating in an auto. just like a multi-speed bike.

Used to be you actually could push-start an automatic. Some of them, anyway (mid-60's and earlier Torqueflites that I know of for certain, and at least one other make). But when tranny rear oil pumps went the way of the dinosaur, so did the ability to push-start automatics.

Without fully recognizing it at the time, drivers gave up a useful capability, trading a measure of self-reliance for greater dependence on others.

An automatic needs fluid pressure in order to apply any of the friction elements that put the thing into any gear, choose in a CVT whether things would spin in the forward or reverse direction, or as I suspect to generate sufficient CVT "belt" friction to actually turn the engine over. So as long as the only tranny pump is on the engine side of where neutral lives - as it must be for normal operation - you can't develop any tranny oil pressure to run the things in it by turning the axle side no matter what the speed.


Norm

So if I understand correctly the turn off at 55 and turn on (ignition only) procedure I used was only a result of sufficient fluid pressure remaining in the CVT (that had yet to fully spin down or drain down) that allowed the transfer of power from the wheels to the engine and that the only source of that "pressure" is from the engine proper? That makes some degree of sense but I guess to understand that "hydraulic pump" and where it "lives!"

I've got to educate myself more on that design.

I will try a bit of a test in the driveway in the interim. If, in the morning, I put the car in gear without the engine on, brake off, the car should easily roll down the drive as if it where in neutral (I would assume it should be completely "drained" in 5 hours time. Sounds like a plan. If it doesn't, then I would think there is more going on than engine only pressure and dig deeper. Thanks Norm!

no you have it all wrong. all norm did was go a little more into detail on the mechanics of the cvt/auto transmission. but this is all irrelevant on your start stop question.

the turn on and turn off works completely independent of your speed. you can do it at 0mph 7mph 26mph 52mph 89mph 120mph 390 mph 4,867mph. your ignition is NOT connected to ANYTHING but your starter, your ignition cylinder, and battery. wherever you heard that speed has anything to do with turning your car on or off, was wrong.

if you want ill take a video of my doing it at any speed you specify to show you. or you can try it yourself. It would be incredibly dangerous to only allow you to turn your ignition on or off under emergencies ONLY at a specific speed.

if you do it yourself, remember you will lose power steering, and you can only apply your brakes once before it gets harder to press. to do it safely, or if you are in a run-a-way car.

you simply take your foot off the gas and brakes, it does not matter how fast you are going.

put your car into neutral.

turn your key off, or if you have push button, you press and hold the button until the engine turns off.

press on the brakes firmly and come to a complete stop without pumping them.

if you are doing it for fun or curiosity, put your car into neutral (it does not matter what speed you are traveling), turn the key off or push and hold the push button,

once the engine is off, you will be coasting with no power, just simply turn the key as if you were starting your car in a parking lot, or push the push button ignition.

your car will start just like normal, and don't forget to put your car back in drive.

this will not harm your car in any way no matter how many times you do it. your car was built specifically to do this.

I practiced something like this soon after I bought my 7th gen over two years ago.

I always have a fear of the engine dying while I am sailing along in the sixth lane of a ten lane packed Atlanta expressway.

I have a very long driveway, so headed down the drive at around 30MPH.

Then I pushed the stop switch, simulating the engine suddenly cutting off as I was driving.

I moved the tranny lever to 'neutral', pressed very lightly on the brakes (so as not to cause a pileup on the freeway), and pushed the START button.

The engine started, and I eased the tranny back into 'D' and continued down the driveway.

Perhaps I didn't explain it correctly....I've turned the ignition off...engine dies...no rpms..no anything but running at 55mph....with the car still in gear...Sans Brake..touch the start button again (to run) and voila' the car refires.....No Neutral Involved, No brakes involved...no "Starter Motor" involved. As far as I know...you can press the start/run button all day long but if it is in gear and/or your foot isn't on the brake...the starter...she ain't gonna engage! I must admit that I didn't know you could start the car in Neutral without touching the brakes. I'll try that as well. Thanks!

you dont really have to worry about the starter breaking on push button because you cant accidentally try to turn it on while the car is on.

I had some very light traffic today on the way to work and while I can't find many hills here in Florida to go down from engine off and cold perspective...but here is what I noted while car was running.

Speed 35 MPH..turn off ignition by holding down the button...car still in gear....press button back to "on" not accessory and car will refire. If in neutral, you must press brake to start.

Speed 25 MPH...repeat above process....car will NOT refire in gear..must either go to neutral and press brake to start or stop completely and put in park with brake depressed.

If I get a day off (a rarity for us IT types) I may just find a hill and see what happens from an engine off perspective and see if I can get it over 35 before putting in gear and hitting ignition.

I've always been told I'm too darn'd curious!

I been doing some thinking in this push button start/stop. I know if you want to turn it off moving or not moving push the button, to restart it push the button, if your battery is dead on the key fob, insert it in the adapter by your left knee, BUT if your push start/stop button dies, either the button or the computer driving the button dies there is no way to start it, just call the flat bed i assume.

Side track comment-

I am from St. Louis area and love going to the Ozarks, I make it a point to float and camp on the Jack's Fork river twice a year( I have been going there since I was a kid- 20+ years). It is so gorgeous on the stretches above Eminence, I love swimming and snorkeling and the Smallie fishing is always great. I'll be there in a month doing an over night float & camp from Buck Hollow to Alley- CAN'T WAIT!!!!

Little further south and west and you would have me pegged! I just remember all the leaches and ticks and chiggers growing up!!! That and growing rocks. I swear, every time I'd plow that field I would end up harvesting another foot for the brick walls. Sure was glad when we got the tractor!!