Auto Start/Stop

[BroncMan]

Hi All,
I have a concern with the auto stop/start feature.
It stops as it supposed to do, but then, when releasing the brake pedal, it won't start again.
I have to slightly touch the gas pedal and then it will come on.
At the same time I noticed that my idle, when engine is at operating temp, is just under 1000 rpm.
Meaning, at still stand, engine running, releasing the brake pedal, the car should start slowly move forward ...
but it doesn't ... until I slightly touch the gas.

Is it possible that the idle is too low and prevents auto start from restarting?

Thanks

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[davidg4781]

Do you have the brake hold on, too? Since you can take your foot off the brake when that's on, the BS doesn't know when you're ready to go until you put your foot on the accelerator.

My annoyance with the auto start/stop is when I'm coming home to park, it'll turn off as soon as I park then turns on when I put it in Park. I don't like it turning on/off so quick.

 

[Mark S.]

My annoyance with the auto start/stop is when I'm coming home to park, it'll turn off as soon as I park then turns on when I put it in Park. I don't like it turning on/off so quick.

Instead of putting it in park just turn off the car; it will automatically return the shifter to park for you.

 

[Bucko]

Do you have the brake hold on, too? Since you can take your foot off the brake when that's on, the BS doesn't know when you're ready to go until you put your foot on the accelerator.

My annoyance with the auto start/stop is when I'm coming home to park, it'll turn off as soon as I park then turns on when I put it in Park. I don't like it turning on/off so quick.

I had heard eons ago that you should run an engine equipped with a turbo for 30 seconds before shutting it down, to allow oil to cool (?) the turbine. This auto shutdown would negate this. Is it still true about turbo engines to let them run for a short period of time before shutdown?

 

[Hot Rod Mike]

I had heard eons ago that you should run an engine equipped with a turbo for 30 seconds before shutting it down, to allow oil to cool (?) the turbine. This auto shutdown would negate this. Is it still true about turbo engines to let them run for a short period of time before shutdown?

You only let to need the Turbo cool down for 30 seconds or so if you have run the car hard like on the freeway

 

[Mark S.]

Is it still true about turbo engines to let them run for a short period of time before shutdown?

It depends on the specific car, but generally speaking this isn't an issue for newer turbocharged engines. In the past the only cooling provided for the turbine bearings was engine oil. For those vehicles, the 30-second interval prior to shutting off the engine kept fresh oil circulating over the turbine bearings until they cooled down. If you shut the engine down immediately the oil trapped near the turbine bearings would absorb all the residual heat resulting in coking. Do that enough and the bearings no longer spin.

Modern turbochargers use the engine's coolant and engine oil for cooling (some use both), keeping the bearings cool enough to negate the need for a cool down.

If you're running your car on a race track you might consider idling the engine a bit before shut down to allow the coolant to absorb residual heat, but under normal circumstances the turbine bearings will never get hot enough to require a cool down period prior to engine shut down.

 

[BroncMan]

It depends on the specific car, but generally speaking this isn't an issue for newer turbocharged engines. In the past the only cooling provided for the turbine bearings was engine oil. For those vehicles, the 30-second interval prior to shutting off the engine kept fresh oil circulating over the turbine bearings until they cooled down. If you shut the engine down immediately the oil trapped near the turbine bearings would absorb all the residual heat resulting in coking. Do that enough and the bearings no longer spin.

Modern turbochargers use the engine's coolant and/or engine oil for cooling (some use both), keeping the bearings cool enough to negate the need for a cool down.

If you're running your car on a race track you might consider idling the engine a bit before shut down to allow the coolant to absorb residual heat, but under normal circumstances the turbine bearings will never get hot enough to require a cool down period prior to engine shut down.

Hi Guys,
to all the above ... the question seems to have taken a completely different turn and answers have nothing to do with the question. There was nothing about shutting off, oil pressure, etc.
The question was: why does auto stop/start not re-start after releasing the break pedal?
It seems that posts take a life on their own veering off into completely different directions.

 

[Bucko]

Hi Guys,
to all the above ... the question seems to have taken a completely different turn and answers have nothing to do with the question. There was nothing about shutting off, oil pressure, etc.
The question was: why does auto stop/start not re-start after releasing the break pedal?
It seems that posts take a life on their own veering off into completely different directions.

My reply was for this reason of an auto start/stop feature...

davidg4781 said:
...My annoyance with the auto start/stop is when I'm coming home to park, it'll turn off as soon as I park then turns on when I put it in Park. I don't like it turning on/off so quick.

It made me wonder if the auto stop/start feature took into effect if the turbo needed a brief period of time to cool, which in turn could effect the auto start/stop.

I did not intend to hijack the thread; was merely considering a potential reason for auto start/stop peculiarities.

And responses to your thread keep it at the top of a forum. Think if it as a free bump.

 

[BroncMan]

No offence ... but it is basically hijacked. Totally different topic.
What to do now?
Have to re-post from scratch to avoid going further into your direction

 

[Mark S.]

Hi Guys,
to all the above ... the question seems to have taken a completely different turn and answers have nothing to do with the question.

Side comments are common on threads like this. I think the best answer to your query came from @davidg4781. If you are using auto hold to hold the brakes for you the engine will not restart when you let your foot off the brake; that would defeat the purpose of the feature.

 

[BroncMan]

I'm aware of this and it's not the cause

 

[Bucko]

Was it serviced for anything recently?

 

[Mark S.]

I'm aware of this and it's not the cause

Well, I always say when in doubt, whip it out. The Owner's Manual that is:

Automatic Engine Restart

Any of the following conditions results in an automatic restart of the engine if:

• You remove your foot from the brake pedal.​

​

If yours does not behave this way then there is something wrong with the system. You should take it in and have it diagnosed.

 

[Mark S.]

FYI: I just drove my Badlands and tested the system. With both Auto Hold & Auto-Start-Stop engaged the engine does not automatically restart when I take my foot off the brake. With Auto Hold disengaged the engine starts as soon as I lift my foot off the brake. I would urge you to doublecheck your system to ensure Auto Hold is not engaged. If it's not and your engine doesn't immediately restart when you take your foot off the brake then your system is not functioning properly.

I didn't check my idle speed, but I don't think that has anything to do with your issue. 1000 RPM idle seems high to me, but my car doesn't have the same engine as yours.

 

[Glamdring70]

The auto hold is on. That's exactly how mine works. You have to hit the gas to restart the car. Alternatively you can yank the wheel a bit and the engine will come on to provide power assist.

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