What if a stick car just dies on the highway?

[Erin]

I am still new to manual cars…

Seeing how in a manual, the wheels are basically “locked” to the engine, I wonder something –
If you have it in gear and the engine just loses power like say the ignition or fuel system fails, how abruptly does the car stop or would the wheels keep engine turning or…?

I got to wondering that cause the other day I tried to “park” the car in 4th or 5th gear (didn’t use E-brake), I didn’t think it mattered until it started to slowly roll since it was on a slight incline. Come to find out, in high gears the wheels can drive the engine, so to speak… Note to self – FIRST gear serves as park, along with E brake…

So what of it? I mean would this be a serious catastrophe if losing engine power on the highway? I mean yeah you could put it in neutral real quick but for that second when the engine died but car rolling, what would that mean for the engine, the car itself, and one’s safety?

Topic

[Cameron]

Whether in a manual or auto it is dangerous if your engine expires and your car begins to decelerate in traffic . Which is why we need to maintain our engines well and not temporarily ignore check engine lights and other warnings as they appear or go for band aid solutions.

It is not a big deal just because you have a manual gearbox because the momentum of your heavy car will keep everything turning over as you decelerate. Bear in mind that a dead engine can be rotated by hand so there is not going to be a massive resistance from the dead engine. Whatever additional resistance there is from a dead engine can be neutralised by depressing the clutch which you can do in under two seconds.

The big issue when your engine expires is the loss of power steering assistance making it very hard to steer the car and a loss of brake booster pressure so after one brake application you will have little if any booster assistance on a second application.

You should know by now that, when parking a manual car, drop it into first gear or reverse gear as appropriate when you are parked. So if parked forward facing down on a steep incline pop it in reverse and angle the wheels to a kerb if there is one. The car will not roll forward down a hill when reverse gear is selected when parked. If parked facing forward on an upwards incline park it in first gear and the car will not roll backwards down the hill. If the hand brake system fails the car will not roll on its own if the manual gear box is set in either of those gears.

[Nicholas Clark]

It’s a 6 of 1 half dozen of the other type of thing. The only real problem you could have is when you engine just seizes from lack of oil or coolant. Most modern cars would be flashing about 100 warning lights at you by that time. In an auto, a seized engine on the highway would put tremendous strain on the torque converter and lock the wheels, but you can throw it in neutral. In a stick. you can hit the clutch. Easier said than done for both situations. I think in a stick it would be easier to notice. Additionally, I think the stick car would have a harder time seizing because the momentum of the car would force the crank to rotate. You would really have a molten mass of metal when you were done, though.

[Mike]

The advice about parking in reverse/first gear, depending upon slope, is a persistent myth. If the car is going to roll due to gravity, it’s going to roll, regardless of the selected gear. Engine compression is what keeps the car from rolling, not the gear. Gears are happy to turn in either direction.

Use first gear when parking, regardless of slope. It saves having the reverse lighting switch needlessly depressed for extended periods when reverse is selected.

[Joseph C]

One of the good things about just about every manual trans I have ever seen is that you CAN “pop-start” from a dead battery. I left the lights on by accident for three hours. Yes.. Battery died . Pop-started (roll car, doesn’t have to be going too fast but kind of fast, pop clutch and turn key at same time, when you realize it starts rev it a little, stop car, clutch down, take off.) And that was just before a long highway drive so I think I was ok.

And I got really lucky because if that was an auto trans, as most care are … I’d have been stuck. At the worst possible time.

+1 on engine sieze being worst possible. Some people say you can let MMO or trans fluid sit in cylinders and let it work its way free (heat applied and ATF+Acetone is way more aggressive if going that route, along with prayer and trying turning by hand every day or so, praying your cylinder walls didn’t get all chewed up) but I’m not sure…

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[Joseph C]

[quote=”Summer_Night” post=161404]I am still new to manual cars…

Seeing how in a manual, the wheels are basically “locked” to the engine, I wonder something –
If you have it in gear and the engine just loses power like say the ignition or fuel system fails, how abruptly does the car stop or would the wheels keep engine turning or…?

I got to wondering that cause the other day I tried to “park” the car in 4th or 5th gear (didn’t use E-brake), I didn’t think it mattered until it started to slowly roll since it was on a slight incline. Come to find out, in high gears the wheels can drive the engine, so to speak… Note to self – FIRST gear serves as park, along with E brake…

So what of it? I mean would this be a serious catastrophe if losing engine power on the highway? I mean yeah you could put it in neutral real quick but for that second when the engine died but car rolling, what would that mean for the engine, the car itself, and one’s safety?[/quote]
About being “locked to the engine,” when the engine is turning at a 1:1 ratio (high gear) then MAYBE. The clutch is the intermediary.

The least amount of time you have the clutch engaged in any situation, the better.

Though, I have my own question.. I have a 99 Nissan Maxima stick shift. Where do I change the manual transmission fluid? And is it engine oil? Its been a very long time for me with stick shift cars.. I forget all details.

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[Mike]

[quote=”Summer_Night” post=161404]..but for that second when the engine died but car rolling, what would that mean for the engine, the car itself, and one’s safety?[/quote]

Nothing at all.

Every time you are coasting in gear and your foot is off the gas pedal completely, you are simulating this condition. Next time you’re alone on a road doing 50mph, let off and start coasting, then turn the ignition key off completely (don’t remove it or your steering will lock). During that time, the engine is still pressurized and supported normally by oil. The car’s momentum is spinning the engine instead of the combustion process, but the engine doesn’t care. It only cares to be lubricated. You can then just switch the ignition back on and start driving again, no starter or conventional starting. You could switch it off, and push the clutch in, and your engine would stop completely. Then you could let the clutch back out, pulling the engine back up to a few thousand RPM, and switch the key back on and drive normally.

When flat towing a stick shift car that’s dead but the engine is mechanically normal, I have it in gear with the engine being spun by road speed. Since the towed car needs to create drag to keep tension on the tow strap, this is far better than having to ride the brakes the whole time. This is especially true if towing a long distance. Extended flat towing can get brakes as hot enough to fade if you’re careless about it.

I remember having a lot of questions like this when I was learning stick shift. Did you know that you can put the transmission in and out of gear seamlessly without using the clutch? If you manually adjust the RPM to what it would be after you engaged the gear normally, the shifter will go into that gear without ever using the clutch. If you are in gear and give the right amount of gas to that you’re not accelerating or coasting, not loading the gear in either direction, you can pull the shifter into neutral quickly and easily without touching the clutch.

[Author]

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