Stop / Start - Here's a question for you all??????

[RickT]

As the new A4 will becoming with the stop / start option it got me thinking....

How will the stop / Start feature affect the life of the Turbo??

Turbo's need the oil circulating to carry the tremendous heat away. After a hard or not so hard run your EGT (exhaust gas temps) should be reduced before shutdown. Of course no one specs their apparatus/cars with EGT gauges.


Glad the below text from another forum to save me re-writing something similar.)

The main reason is to allow the turbo to spin down from the very high RPM (100k rpm isn't unusual) that it spins at while it's still being fed oil by the mechanical oil pump in the engine. Shut the engine off before it's had a chance to spin down and you cut the oil feed - that's what ruins the bearings.

It's the same for petrol turbo cars, although they typically have the turbo begin working at higher RPM than a diesel (my Tdi hit's peak boost at around 1,800 RPM whereas my old MR2 turbo it was closer to 4,000 RPM) you can avoid prolonged idling (also bad for the engine btw) by simply driving it nicely for the last few miles of your journey and avoid heavy turbo usage.

Some turbos (no LR ones to my knowledge) are liquid cooled by the engine coolant although the second generation MR2 turbo certainly was and heat soak from the turbo could, potentially, boil the coolant in the turbo if the engine was shut down without allowing the engine to idle and cool the turbo off first. This coupled with the oil stavation could ruin the turbo, or in extreme cases blow the turbo coolant piping which leads to a total coolant loss - if you don't notice before driving it again (I know... but you'd be amazed at what some people don't notice) you could kiss goodbye to the head gasket, the head or even the whole engine.

TD, Tdi and TD5 (sorry, don't know about the TDV6 and 8's) Land Rover engines do not feed coolant to the turbo and spin down will take less than 30 seconds. If you've been using the engine and turbo very hard (long uphill for example) immediately before shutting off, give it the full 30 seconds before you
shut it down


i expect that many TDI or "T" owners dont allow the turbo to cool down after a hard or long drive but with the option of the car stopping and starting when you stop surely this is going to allow the turbo not to displace heat if you let it idle.


I would be interested on peoples thoughts with this.....

Rick

[Hex69]

As the new A4 will becoming with the stop / start option it got me thinking....

How will the stop / Start feature affect the life of the Turbo??

Turbo's need the oil circulating to carry the tremendous heat away. After a hard or not so hard run your EGT (exhaust gas temps) should be reduced before shutdown. Of course no one specs their apparatus/cars with EGT gauges.


Glad the below text from another forum to save me re-writing something similar.)



i expect that many TDI or "T" owners dont allow the turbo to cool down after a hard or long drive but with the option of the car stopping and starting when you stop surely this is going to allow the turbo not to displace heat if you let it idle.


I would be interested on peoples thoughts with this.....

Rick

I've heard, but may be wrong, that as long as you spend the last 30 secs to a minute of your journey 'off boost', you should be ok.

The problem is going to be with people who have no mechanical knowledge/sympathy who will just switch off anyway, in which case there's no difference to before.

[ScottyUK]

My TT used to pump it around to cool the tubro for a couple of mins after turning if off.

Apparently the A4 doesn't need to but I shame the concern.

[paul b]

Like Hex, I totally back of for the last part of the journey, sometimes just coasting if the road is empty.

Other times though, I put the car on the drive, which is low revs for more than 30 secs. I am sure this is the cooling down period criteria met.

[macmillions]

I nag my dad all the time about his megane 1.5 dci. He drives all the way from manchester to dunmow (over 3hrs every friday, then back up on monday nights) and pulls in the drive and switches off straight away. I keep tellng him he'll need a new turbo one of these days.

Still taking no notice though... :banghead:

[MalcQV]

Interesting subject but no-one directly answered Rick's question.

I guess Audi must know the car, Don't these systems usually wait about a minute before switching the engine off? I guess as the guys say providing you have not been using the turbo prior to switch off it is OK. Is one minute enough?

[paul b]

With regards to how it affects the life of the turbo...

The oil is very, very hot in the turbo. Switching off the engine after heavy driving would cut the oil pump out, leaving hot oil in the turbo with nowhere to go. The hot oil in the turbo can cook the bearings. The other extreme is if the oil burns it can choke the oil supply to the turbo.

All explained under "reliability" here (http://en.wikipedia.org/wiki/Turbocharger). ;)

[Black Phantom]

What is this stop/start option that you speak of?:confused:

[STEWY L]

hello lads,
i feel the turbo should be ok because,as i understand it,the stop/start
feature would function whilst in traffic,bumper to bumper,or standing at lights?
the turbo wouldn't be being used in most of that time.
i can't see it just simply switching off after a heavy burst,or long run.
my tuppence worth,
regards,
stewy.

[ScottyUK]

What is this stop/start option that you speak of?:confused:

It's not an option. If you buy a MY2010 2.0 A4 then you'll get it.


Automatic start/stop function for greater fuel and C02 efficiency. Comprising;
– Recuperation for optimal energy utilisation
– Energy saving tips feature in Driver’s Information System;
including gearshift indicator
(Only available on the 2.0 TDI/2.0 TFSI manual engines)

[troc]

My mother's 1980's fiat panda had a start-stop system, way ahead of it's time. It was very clever. It operated when it was raining mostly - we would come to a halt at the lights, the engine would die, I'd have to get out, open the bonnet and spray copious amounts of WD-40 over the HT leads and then we could start up again, drive to the next set of lights and repeat.

That's italian engineering in action :)

[MalcQV]

My mother's 1980's fiat panda had a start-stop system, way ahead of it's time. It was very clever. It operated when it was raining mostly - we would come to a halt at the lights, the engine would die, I'd have to get out, open the bonnet and spray copious amounts of WD-40 over the HT leads and then we could start up again, drive to the next set of lights and repeat.

That's italian engineering in action :)
:D:D:D Oh yes indeedy. The Italians in the 80's connected cables using candle wax or something :p. Very poor indeed. :o

[mc11]

Hi guys. I'm a little confused with all this turbo talk. I thought that once you got somewhere all you needed to do was to switch the car off. How comes you need to cool the turbo? And how and why do you do this?

cheeers

[paul b]

Hi guys. I'm a little confused with all this turbo talk. I thought that once you got somewhere all you needed to do was to switch the car off. How comes you need to cool the turbo? And how and why do you do this?

cheeers
Read.

I've heard, but may be wrong, that as long as you spend the last 30 secs to a minute of your journey 'off boost', you should be ok.

The problem is going to be with people who have no mechanical knowledge/sympathy who will just switch off anyway, in which case there's no difference to before.
The above is how.

With regards to how it affects the life of the turbo...

The oil is very, very hot in the turbo. Switching off the engine after heavy driving would cut the oil pump out, leaving hot oil in the turbo with nowhere to go. The hot oil in the turbo can cook the bearings. The other extreme is if the oil burns it can choke the oil supply to the turbo.

All explained under "reliability" here (http://en.wikipedia.org/wiki/Turbocharger). ;)
And the above here is why.

[Stu8]

Would this also work the opposite way? We all know that short journeys on a cold engine can be damaging. If you live in a busy city, will the car keep turning itself off in stop start traffic even if you have only been driving a few minutes? Will this therefore mean that the engine will be switched off then back on a lot when cold? Could this result in longer warm up periods and less engine efficiency?

[ScottyUK]

I wonder if the engine will go off if you have the AC running? If so how will you be kept cool :(

I've got the feeling it'll be very rare mine cuts the engine out....but at least *** means the tax group is down even if it's never used ! :D

[zollaf]

i can see it now, your in a long tailback on a motorway, you keep moving forwards a bit at a time , then after a few hours of this stopping and starting you get a flat battery and no more starting. what then??? someone kindly gives you a jump start, you move forward and stop.

[ScottyUK]

Two things :

[1] you can turn it off to protect yourself from this

[2] the power management in the B8 A4 is now quite clever. If the power starts getting low it'll turn off A/C, radio etc etc thus protecting you so you have something to start the car. If you carry on with this without turning off stop start then you probably deserve a flat battery ;)

[mallymclane]

surely an expensive well made car like the audi a4 is clever enough to pump the oil away after I have turned the ignition off...?

I'm thinking about my oven, who's fan still goes even after I've turned it off, persumably to get rid of the heat ;-)

[rd1]

[QUOTE]surely an expensive well made car like the audi a4 is clever enough to pump the oil away after I have turned the ignition off...?

This must be the case, pumps in other industries have been using this technology for years (Godiva etc) by using secondary cooling to disperse trapped heat or by using bypass arrangements for the controlled leaking away of the hot product when turned off.

I feel sure that this must have been one of those many new 'space age' patents that Audi advertised and launched the new models on.
An expert Audi view on the technology is needed, it must have progressed since I had this same debate concerning my old 90s Ford Escort 1.8 Turbo.
Well lets hope so anyway:confused:.

[ScottyUK]

If you're owners of a B8 then you've bought either a brand new car of a nearly new car.

This being the case how many of you will be running the car at 100 - 150 k miles?

Not many i'd guess. Therefore who gives a ****! I honestly can't see there being a problem so just chill, crack open a few Belgium beers (can you tell I have? :biglaugh:) and enjoy the car when it arrives. ;)

[Black Phantom]

If you're owners of a B8 then you've bought either a brand new car of a nearly new car.

This being the case how many of you will be running the car at 100 - 150 k miles?

Not many i'd guess. Therefore who gives a ****! I honestly can't see there being a problem so just chill, crack open a few Belgium beers (can you tell I have? :biglaugh:) and enjoy the car when it arrives. ;)

This is a good answer. The best ones usually come after an intake of alcohol. Good for you Scotty!:beerchug:

[RickT]

But taking into account the amount of turbo issues on the B7 with the 2.0 TDI, (140 & 170bhp Version) it will be interesting to see how this pans out.

Rick

[onemanparty]

But taking into account the amount of turbo issues on the B7 with the 2.0 TDI, (140 & 170bhp Version) it will be interesting to see how this pans out.

Rick


Very true but different engines with the switch from PD to Common Rail

[jonathon555]

Turbo should be fine as the new generation of oils are so much better than they use to be.

In cold wethear is where it will bothoer me most as the heater won't get up to temperature very quickly. if the engine keeps turning off.

[viv carey]

HI YALL, Believe you can fit a turbo timer, anyone know if they are any good, or worth the trouble.:(

[streetfighter-r]

Interesting thread and certainly I need to bear in mind when my 2.0T arrives in a few days...

Anyway, back to the original question, I understand this only works when you are neutral and off the clutch, and the engine restarts when you depress the clutch again...

Solution: keep you left foot on the clutch even in heavy traffic! Luckily auto Stop/Start doesn't apply to autos...

[ScottyUK]

I wouldn't bother with a turbo timer. Audi had one on my old TT. It just ran oil for a minute or two after ignition off. If Audi don't feel the need on the A4 then I have to go with them. They know a lot more about the car than me.

[Geordie Amanda]

My previous car (BMW 123D) had stop/start as well as twin turbos and it never missed a beat. I did pretty high mileage for nearly 3 years and the car never needed topping up with oil, or blew smoke out of the exhaust. The stop start worked instantly as long as the temp wasn't too cold outside and the engine was warmish. I believe the BMW system works better than the Audi system, or at least it did, but I now find I really miss it on my current car, especially as I can see the mpg go down while idling at lights now:( I did drive my car fairly enthusiastically too, so it got pretty hot under the bonnet. I love stop/start :)

btw, the BMW system had a switch so you could disable the stop/start if it annoyed you, which it could when you were stuck in motorway traffic.

[johnloaderuk]

Luckily auto Stop/Start doesn't apply to autos...

Unless you have it on a Passat CC with DSG, in which case you do get Stop/Start. I also think the new Passat B7 has this when it comes out later this year with DSG. As long as you keep the foot brake down it stops, then restarts when you take your foot off the brake.

I've have Stop/Start on my 2010 Passat 2.0TDI 140 CR and also like it. Does make me wonder why all cars don't have it as there's really no need for the engine to keep going when you aren't moving, you soon get used to it.

[johnloaderuk]

In cold wethear is where it will bothoer me most as the heater won't get up to temperature very quickly. if the engine keeps turning off.

The system knows if the interior isn't up to the selected temperature so then keeps the engine running - that's how it works on my Passat. It's quite intellegent in that respect.

[black999]

I recently had some work done on my 2008 A4 and the dealership loaned me a "new" A3 for the duration. This car had the start/stop feature but it could be turned off by a button on the dash.

Is this the case with the new A4 or is the function "on" all of the time ?

[certacito]

I recently had some work done on my 2008 A4 and the dealership loaned me a "new" A3 for the duration. This car had the start/stop feature but it could be turned off by a button on the dash.

Is this the case with the new A4 or is the function "on" all of the time ?

Same for B8 A4 - There is a button on the centre console where it can be turned off.

Also noticed that mine hardly activates at all when the weather is cold. There are lots of criteria that have to be met before the engine stops it appears to quite a complex algorithm they use to activate it.

[dave1956]

hi all very interresting thread i dont have an audi yet still driving an 11 year old swedish missile my turbo seal s failed at idle one day because centre of turbo housing was clogged with sludge from old oil coke and i religious in lettin car idle for a lil while after a journey also an example from my proffesion the machines we use at work have to stabalise engine temprature from flight idle to gnd idle for some two minutes before being shut down to prevent engine damage [they are just like big turbos ]i get my a4 avant in june and stop start will be switched off v/bad idea to please greenpeace :D

[ScottyUK]

Hi and welcome.

errm on your keyboard directly to the right of letter M there should be two keys. Do your's work?

p.s. If you're using a smart phone then they may be hidden elsewhere ;)

[dave1956]

lol ,hi scotty. thanks for the welcome ;).i some times forget to use those bad habits i suppose.

[ScottyUK]

aha! I can (nearly) understand that post ! :D

[J_B204]

My first post, so hello all!

Been lurking on the forums for a little while - anyway decided to register as I've just ordered my new A4 Avant 170 PS Quattro Technik In bright red!!! With Tech pack high (HDD Sat Nav) & lighting pack..

Delivery early May...so painful!

Anyway, being sad I downloaded the brochure from this site and read all about the stop start...

Here goes:

Stop Start will not operate until the engine is up to operating temp.
If the system detects extra load on the electrical system (AC etc) it will not activate
If the battery condition isn't tip top it won't activate.
As already said it will selectively deactivate things that are draining the battery if there is a problem (but this isn't linked to the stop start necessarily - this is all about the health of the battery)
You can deactivate but, personally I don't see the need to as it is pretty smart at monitoring the health of the battery/engine etc.
Re turbo - not sure about this once but would be very surprised if there wasn't a fail safe in there to protect the turbo, that combined with advanced oils means it 'should' be ok.

Anyway, my first post, so hope this helps!

[cpridd]

J_B204...hello! I am a newbie too after having been lurking for a while like you!

Having just got my A4, this is the first time I have had a car with start-stop. I have been really impressed with it so far. I guess because the weather has been cold, it hasn't been kicking in too much, and my recentt journeys have been shorter than normal, so this may explain. It starts up as soon as you touch the clutch, which is pretty cool! I wonder what is the optimum time for a stop to occur before you are making a saving, e.g. is a 15 second cut out + a restart better or worse than pressing the button and keeping the engine running in terms or ecomonmy/fuel saving? There must be extra fuel needed for the engine to restart? I am sure there must be a time when it begins to be more efficient? Any ideas?

Btw, I too downloaded the handbook before purchase...sad? No, I always do this before buying anything for two reasons, one, you know how to use it when you get the item, two, helps you get a real understanding of what you are going to buy. Maybe this is sad!?

[J_B204]

cpridd,

I seem to remember that with any stop over 30 secs it is worth turning your engine off (to save fuel - although if it happens a lot you may suffer from excess wear and tear) but that is with standard (older) engines. The modern stop/start system will be much more efficient so I reckon your 15 secs is about right. After all, when you stop at a traffic light odds-on you are going to be there for more than 30 secs.

J_B204

[sharantdi]

its easy to dissable it....I have done that using VCDS and I realy dont miss it.. I was worried for both my turbo and engine starter which is used more often to start the engine . Gain in petrol consumtion is minimal...this is ment as envirement measure to lower co2 from the car... If you dont have vcds cable you still have button to stopp start\stopp function but this way you have to pres this button each time you start the car.



It's not an option. If you buy a MY2010 2.0 A4 then you'll get it.


Automatic start/stop function for greater fuel and C02 efficiency. Comprising;
– Recuperation for optimal energy utilisation
– Energy saving tips feature in Driver’s Information System;
including gearshift indicator
(Only available on the 2.0 TDI/2.0 TFSI manual engines)

[ScottyUK]

its easy to dissable it....I have done that using VCDS and I realy dont miss it.. I was worried for both my turbo and engine starter which is used more often to start the engine . Gain in petrol consumtion is minimal...this is ment as envirement measure to lower co2 from the car... If you dont have vcds cable you still have button to stopp start\stopp function but this way you have to pres this button each time you start the car.

Can you tell us the codes? :beerchug:

Whether it's active on the car or not, by having it the tax level reduced when they introduced it :D

[sharantdi]

My car is Audi 2.0 tdi 2010 modell. Using VCDS version 10.6.3 select engine ( 01) and than coding (07) and than choose long coding helper....

It is Byte 6 bit 0. Bit 0 must be set from 1 to 0 and save this value....

Again ...this is coding that I used on my car and maybe the coding for your car is different...



Can you tell us the codes? :beerchug:

Whether it's active on the car or not, by having it the tax level reduced when they introduced it :D

[Zafi]

Shame they cant design them to turn off the brake lights and apply the handbrake automatically!!
Very frustrating sitting behind a car that is stationary yet the driver has his foot on the brake pedal :zx11:

[ScottyUK]

Zafi - agreed :D

It's actually shame they didn't get Hill Hold Assist working with in. :(


My car is Audi 2.0 tdi 2010 modell. Using VCDS version 10.6.3 select engine ( 01) and than coding (07) and than choose long coding helper....

It is Byte 6 bit 0. Bit 0 must be set from 1 to 0 and save this value....

Again ...this is coding that I used on my car and maybe the coding for your car is different...

Cheers - I'll try it....just for the sake of it. ;)

[Jason.S]

A timer on the brake lights would help.

Shut off after a minute or so.

[Zafi]

A timer on the brake lights would help.

Shut off after a minute or so.

Now thats a good idea :) 30 seconds would do it.


Here's another... why do hazards flash at the same rate as indicators? You cant tell if the van, parked at the side of the road partially obscured by parked cars, is indicating to pull out or parked with his hazards on.

So with electronics there is no reason why hazards cant flash at a differet rate or one long, one short flash......Dragons Den here I come ;)