Eco stop/start.

[rf065]

So if people think that stop/start is causing problems with the chain, the question to ask is what mechanism would cause the chain to wear prematurely under stop/start conditions.

Having to start the car everytime you stop at junction/lights/roundabouts/traffic jams?
Having to start the engine maybe 100 times a day instead of 2 or 3 times?
Ditching duplex chains and fitting a single chain?

 

[markjay]

I think you’re being a bit naive if you think stop start doesn’t damage the engine in anyway ....

I believe that there are two questions here.

The first is if in principle the chain suffers accelerated wear due to frequent transitions from rest to movement.

The second if is such wear is significant.

The fact that taxis don't seem to suffer issues with timing chains might be explained by answering Yes to the first question and No to the second.

 

[Diesel Benz]

I believe the topic started from a question about the OM651 engine on a W205. If I remember right, the OM651 chain and tensioner issues started way before stop/start was introduced. They did not need stop/start to gain that (initial) poor reputation.

 

[400ixl]

I think you’re being a bit naive if you think stop start doesn’t damage the engine in anyway ....

Every mechanical part gets worn under use, no one is saying it doesn't. Is the wear that stop start adds significant enough to be causing premature failures, there is no evidence to support that it does, at least that anyone has been able to point to. You will always get the odd failure, inevitable with mechanical parts, but the mean time to fail is well beyond the expected life of the engine. This has been around long enough now to have been proven in the wild, not just the lab.

 

[400ixl]

I believe that there are two questions here.

The first is if in principle the chain suffers accelerated wear due to frequent transitions from rest to movement.

The second if is such wear is significant.

The fact that taxis don't seem to suffer issues with timing chains might be explained by answering Yes to the first question and No to the second.

Yep, spot on.

 

[wongl]

Was yours an early 190E. They had a single row timing chain which was known to be a problem. It was replaced with a duplex chain somewhere around 1988/89.

My 190E had a single chain.

 

[wongl]

Every mechanical part gets worn under use, no one is saying it doesn't. Is the wear that stop start adds significant enough to be causing premature failures, there is no evidence to support that it does, at least that anyone has been able to point to. You will always get the odd failure, inevitable with mechanical parts, but the mean time to fail is well beyond the expected life of the engine. This has been around long enough now to have been proven in the wild, not just the lab.

Spot on!

One has to balance the wear and tear of an idling engine, complete with drag on the alternator, torque converter and gear box verses the wear and tear from stopping and starting an engine when the car is stationary.

Every driver has a different driving style, route and traffic condition so the benefits and value of start/stop will be different to each driver, journey etc. I generally drive my SLK with the start/stop enabled, but I do find it annoying in creeping traffic when the start/stop disables itself after 3 sequential cycle without getting over 10kmh.

 

[400ixl]

I am the same, leave it on and switch it off if the need arises due to crawling traffic where I can't be bothered to control the brake pedal in such a was as to have it not cut in when I don't want it too. For example when I want to use the hold function.

It only cuts in if YOU let it. You can be stationary and not have it cut in (when activated) just by the pressure you apply on the brake peddle.

 

[markjay]

I am the same, leave it on and switch it off if the need arises due to crawling traffic where I can't be bothered to control the brake pedal in such a was as to have it not cut in when I don't want it too. For example when I want to use the hold function.

It only cuts in if YOU let it. You can be stationary and not have it cut in (when activated) just by the pressure you apply on the brake peddle.

The Stop/Start and HOLD functions are not mutually exclusive (on my W204 anyway).

If I brake and then press hard (with Stop/Start enabled), the engine will switch off and the HOLD will engage.

Lifting my foot from the brake pedal does not cause the engine to start.

When I touch the accelerator, HOLD is released and the engine starts.

 

[wongl]

The Stop/Start and HOLD functions are not mutually exclusive (on my W204 anyway).

If I brake and then press hard (with Stop/Start enabled), the engine will switch off and the HOLD will engage.

Lifting my foot from the brake pedal does not cause the engine to start.

When I touch the accelerator, HOLD is released and the engine starts.

The start/stop function operates the same as yours in my R172, W205 and W246, although the start/stop is much more aggressive (at cutting out the engine) on my W205 since it is the hybrid diesel C300h where the engine will cut out the moment you lift the accelerate while the car is still rolling and also on over run (when the high voltage battery is also being regenerated)..

On the W246 it seems that the gearbox disengages on over run so that the engine returns to idle speed rpm.

 

[400ixl]

The Stop/Start and HOLD functions are not mutually exclusive (on my W204 anyway).

If I brake and then press hard (with Stop/Start enabled), the engine will switch off and the HOLD will engage.

Lifting my foot from the brake pedal does not cause the engine to start.

When I touch the accelerator, HOLD is released and the engine starts.

Not quite what I was meaning.

I can come to a complete halt and stay halted without the stop start kicking in (when active) by applying the right pressure to the peddle. I cannot however engage hold and not have stop start engage. This is when I consider whether to switch off stop start.

Stop start does not need to engage everytime you come to a halt at traffic lights as some people imply.

 

[markjay]

Stop/Start is a relatively basic system.

You'll need to apply a serious amount of both hardware (sensors/cameras) and AI software to the system if you want it to know when to switch-off and when not to, e.g. depending on traffic conditions etc' (or, in short, doing what the human brain would have done).

But given that EVs are the future, I doubt anyone will invest the resources required for developing a smart Stop/Start system for IC-engined cars....

 

[400ixl]

Indeed, until smart cities come along you wouldn't have the information required. The camera already in the car could be used to some degree, but not enough over the driver making simple use of the tools at their disposal and not just using the brake as an on off switch.

E.g. how long is it before the traffic light you are sat at is going to go to green.

 

[Tonygw]

I switch off the start stop for one reason, beacuse it simply annoys me and i have no inclination to learn how it works.
When I am driving I like the engine to be on and when I park I like it to be off
The end .....

 

[ShaunB]

But given that EVs are the future

Debatable.
They may work for some people in their current form, but range is limited, and battery life questionable for the 2nd hand market.

 

[DITTRICH]

I have noticed that if I am very light on the brake, it is possible to keep the engine running even if start/stop is enabled. However, unless you are carefully watching, you might start creeping forwards, at which point further pressure on the brake might well trigger start/stop. That said, the automatic starting regime seems very smooth compared to manually starting that car.

 

[Gazwould]

Pleasingly mine stopped working last year in October as ambient temps lower and the intial reading with the Smart battery charger indicates on the original battery 12.1V.

However it's back working again since the brake servo pressure sensor has been replaced .

I thought it was the sensor at
8 O'Clock on the servo but it hasn't been changed .

 

[400ixl]

I switch off the start stop for one reason, beacuse it simply annoys me and i have no inclination to learn how it works.
When I am driving I like the engine to be on and when I park I like it to be off
The end .....

Perfectly reasonable to me. If it annoys then bin it if possible.

 

[markjay]

Debatable.
They may work for some people in their current form, but range is limited, and battery life questionable for the 2nd hand market.

I agree with everything you say and yet I still think that EV's are the future.... legislation will see to it.

 

[ShaunB]

I agree with everything you say and yet I still think that EV's are the future.... legislation will see to it.

You're probably right, but we are all going to be so disappointed as a result.
Going out in the morning, starting up something that makes absolutely zero noise - FFS
My neighbour has this hybrid Yaris thing, and he loves it, and thinks he's saving the planet too, but boy is it dull, and its definitely not saving anything.