Does the auto start stop system put more wear on motor

[Mess262]

We have the ASS system in my wife’s MB and I rather like it. It is super smooth, very seamless and I have never been able to feel a difference in acceleration at startup from a stop. I really liked it.
in my diesel wrangler JLU it seems much more violent. Now I know Diesel engines are a bit more “violent” but it seems to me that it would pose possible long term issues. Can anyone more versed or experienced with the internals of these motors weigh in on if the ASS could be a long term liability in these. Outside of the battery and starter wear. I’m talking just the engine internals.

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[Some Random Guy]

My understanding is that a start/stop system includes sensors to stop the crank at the optimal position for a quick start. That conveniently also reduces wear/tear and is used during normal start/stop operations as well.

 

[Arterius2]

We have the ASS system in my wife’s MB and I rather like it. It is super smooth, very seamless and I have never been able to feel a difference in acceleration at startup from a stop. I really liked it.
in my diesel wrangler JLU it seems much more violent. Now I know Diesel engines are a bit more “violent” but it seems to me that it would pose possible long term issues. Can anyone more versed or experienced with the internals of these motors weigh in on if the ASS could be a long term liability in these. Outside of the battery and starter wear. I’m talking just the engine internals.

Many people also don’t realize that idling the engine for too long probably causes more wear.

 

[Mess262]

Many people also don’t realize that idling the engine for too long probably causes more wear.

Thankfully I have found this forum for a number of reasons. I learned quite a bit about diesel jeep ownership in just the past 3 days. This forum is active with new model Jeep owners where the other legacy forums just seem dead anymore. This site also doesn’t refresh the screen every time you scroll a page. I have to give my praise for this forum. It really seems to be a wonderfully useful place.

 

[Mess262]

My understanding is that a start/stop system includes sensors to stop the crank at the optimal position for a quick start. That conveniently also reduces wear/tear and is used during normal start/stop operations as well.

Ah very interesting. I knew the MB does some pretty cool stuff with the engine for the ASS as far as compression and the internals but wasn’t sure how these operated. My diesel experience was limited to tractors and old diesel technology.

 

[Capricorn]

My only concern with the stop/start is that even when the turbo is very hot, it still activates and stops the motor. I encounter this everyday as soon as I take an exit from a 25 mile drive at highway speeds and have to stop at a left turn stop signal. Hence whenever I am hitting the ighway, I press the button to turn ESS off.
Yes, a minute and a half stop is not going to cook/coke the synthetic oil but still...I am paranoid about it - and I guess it may just be an irrational fear. Otherwise, I have no other concerns about it. I wished they had programmed ESS to not activate when the EGT1 is at a certain temperature or above it.

 

[Wrangler man]

My only concern with the stop/start is that even when the turbo is very hot, it still activates and stops the motor. I encounter this everyday as soon as I take an exit from a 25 mile drive at highway speeds and have to stop at a left turn stop signal. Hence whenever I am hitting the ighway, I press the button to turn ESS off.
Yes, a minute and a half stop is not going to cook/coke the synthetic oil but still...I am paranoid about it - and I guess it may just be an irrational fear. Otherwise, I have no other concerns about it. I wished they had programmed ESS to not activate when the EGT1 is at a certain temperature or above it.

It's been proven at best the start-stop only improves maybe 1 MPG my concern is not only the turbo being hot but why run a car when the AC is on off the battery start-stop doesn't make any sense it's only on there to appease Big Brother

 

[WXman]

The flywheel and starter motor are engineered for ESS operation. It's not supposed to put additional wear, i.e. shorter lifespan on any components.

For a diesel, idling is particularly bad. This is where the most soot accumulates. And this is where fuel wash-down will occur if it occurs. I find ESS to be a better idea for a diesel. I really like it. They didn't use it on the Ram with the identical powertrain, but they do use it on Wrangler and Gladiator.

 

[Archeonomy]

My BMW ASS is far more violent / noticeable than my Jeep with the 2.0. As a result, I generally deactivate it in the BMW, but I can live with it in the Wrangler.

 

[Capricorn]

It's been proven at best the start-stop only improves maybe 1 MPG my concern is not only the turbo being hot but why run a car when the AC is on off the battery start-stop doesn't make any sense it's only on there to appease Big Brother

The flywheel and starter motor are engineered for ESS operation. It's not supposed to put additional wear, i.e. shorter lifespan on any components.

For a diesel, idling is particularly bad. This is where the most soot accumulates. And this is where fuel wash-down will occur if it occurs. I find ESS to be a better idea for a diesel. I really like it. They didn't use it on the Ram with the identical powertrain, but they do use it on Wrangler and Gladiator.

You are not concerned with a possible negative effect of ESS on the turbo in the long run?

 

[Wrangler man]

We have the ASS system in my wife’s MB and I rather like it. It is super smooth, very seamless and I have never been able to feel a difference in acceleration at startup from a stop. I really liked it.
in my diesel wrangler JLU it seems much more violent. Now I know Diesel engines are a bit more “violent” but it seems to me that it would pose possible long term issues. Can anyone more versed or experienced with the internals of these motors weigh in on if the ASS could be a long term liability in these. Outside of the battery and starter wear. I’m talking just the engine internals.

The flywheel and starter motor are engineered for ESS operation. It's not supposed to put additional wear, i.e. shorter lifespan on any components.

For a diesel, idling is particularly bad. This is where the most soot accumulates. And this is where fuel wash-down will occur if it occurs. I find ESS to be a better idea for a diesel. I really like it. They didn't use it on the Ram with the identical powertrain, but they do use it on Wrangler and Gladiator.

So I paid particular close attention today the current temperature is 80 degrees I have my air conditioner set to 67 degrees inside left the start stop ESS on today it only shuts off momentarily 10 seconds 15 seconds while sitting at red lights,at best, then turns back on. I know this is because I am running the AC. I've operated earlier model Chevy pickup trucks that had this feature and the AC with continue to blow but the engine would not come back on and the AC would end up blowing warm air just a misery to drive so I do appreciate the fact the system allows the engine to come back on quickly rather than sit with hot air being blown in your face. That being said I'm in 100% agreement with you with these new stricter emission diesel engines idling, idling for long periods of time causes more build up and harm where earlier diesels could idle for long periods of time and not have the issues that were faced with today it's a catch-22 all in all in the colder climates the system (ESS) would be ideal in the warmer climates and AC is used on a regular basis it just doesn't work.

 

[Wrangler man]

It's been proven at best the start-stop only improves maybe 1 MPG my concern is not only the turbo being hot but why run a car when the AC is on off the battery start-stop doesn't make any sense it's only on there to appease Big Brother

 

[five9dak]

Yes, every time a hydrodynamic bearing stops spinning it touches down on the bearing shell. If it matters enough in the lifespan of the engine- who knows. But it definitely creating more wear on the bearings (more touch downs), starter (more cycles), alternator(higher load to recharge) and battery (more high current cycles).

This crap is purely for government mandates and fleet fuel economy /emissions reasons. If it wasn't required it wouldn't be there, like the last 100 years of motoring.

 

[WXman]

You are not concerned with a possible negative effect of ESS on the turbo in the long run?

No, not at all. The turbo isn't going to mysteriously bake in the 14 seconds the engine is shut down. These turbos are water and oil cooled. They aren't like the turbos of yesterday.

As far as A/C use goes, that's also a total non-issue. The cabin temperature doesn't increase 30 degrees in the time you spend sitting at a red light. And the BCM also monitors interior temp and turns the engine back on if it does begin to climb.

 

[calemasters]

I don't think ESS on the JLU 3.0 L diesel does any harm, as the vehicle was designed for ESS. But I do find it very annoying when I pull into my garage, then stop the vehicle, then the engine stops, then I put the shifter into Park, then the engine restarts, then I turn off the engine. What a waist.

I like to control the operation of my engine. Not some computer that has no idea that I am home and parking in my garage.

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