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

[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

Oh yes indeedy. The Italians in the 80's connected cables using candle wax or something . Very poor indeed.

[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.

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 !

[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.