Audi stop/start problem

Pronto63

Just purchased a s/h (2014) Audi A5 - happy days!

It has a stop start facility whereby when stopped in traffic the engine cuts out to save fuel and emissions. The car must be in neutral with the handbrake applied.

When you depress the clutch the engine fires up straight away.

The problem is this - on about 4 occasions in the 3 weeks since I got the car the engine cuts out a couple of seconds after restarting. This has left me coasting through a junction with no power while trying to restart the engine!

Anyone else experience this type of problem?

TIA

punisher5112

Bring it back and get them to sort it. You can disable it till you can get sorted.

Meeeee79

Make sure you keep the clutch depressed for long enough. Ive had same issue with my car but only a couple of times and it has been my own fault, changing gears too quickly I suppose. Only happened me at the beginning when I was getting used to the stop start.

Pronto63

punisher5112 wrote: »

Bring it back and get them to sort it. You can disable it till you can get sorted.

I intend to, just rang and left a message. Also know it can be disabled, there is a switch near gear stick.

Just interested to hear experiences of others.

Idleater

Pronto63 wrote: »

Just interested to hear experiences of others.

Just wondering, (I have s/s on the Alfa) when it cuts out for whatever reason (stall etc.) I release and repress the clutch and it restarts - as in I don't have to use the key to turn it off and on again.

Betty.DJohnson

Meeeee79 wrote: »

Make sure you keep the clutch depressed for long enough. Ive had same issue with my car but only a couple of times and it has been my own fault, changing gears too quickly I suppose. Only happened me at the beginning when I was getting used to the stop start.

Happens to me too...

Mooooo

Does stop start actually improve fuel economy? Is it just another thing to make economy figures look better on paper. Can't be great for the engine particularly diesel ones?

Idleater

Mooooo wrote: »

Does stop start actually improve fuel economy? Is it just another thing to make economy figures look better on paper. Can't be great for the engine particularly diesel ones?

By virtue of the engine not actually running, yes, it specifically must improve fuel economy for the 30 seconds that the engine is off, when otherwise it would be on.

Yes it is just another thing to make the figures look better on paper, because in simulated trials of 100% stop start traffic it is beneficial, but in 100% free flowing traffic it is never used, and real life driving in an inefficient manner probably does more to raise fuel usage than S/S ever will save.

There have been many threads on the topic of S/S, and iirc the systems are smart enough to know when not to stop the engine (eg cold winter night with high electrical usage) and when they do stop, they stop the engine in a place that makes starting "easy". My car is a 2010, and I think manufacturers did enough to beef up the starter systems to take the extra usage. I can't comment on diesel.

MarkN

Idleater wrote: »

By virtue of the engine not actually running, yes, it specifically must improve fuel economy for the 30 seconds that the engine is off, when otherwise it would be on.

Yes it is just another thing to make the figures look better on paper, because in simulated trials of 100% stop start traffic it is beneficial, but in 100% free flowing traffic it is never used, and real life driving in an inefficient manner probably does more to raise fuel usage than S/S ever will save.

There have been many threads on the topic of S/S, and iirc the systems are smart enough to know when not to stop the engine (eg cold winter night with high electrical usage) and when they do stop, they stop the engine in a place that makes starting "easy". My car is a 2010, and I think manufacturers did enough to beef up the starter systems to take the extra usage. I can't comment on diesel.

As far as I know, most of these stop starts have a separate battery so get that checked. I’ve had an issue with a 2017 Qashqai losing electrical power and a Nissan mechanic told me the battery in the stop start can be the cause.

Tuco88

The stop/start tec is usless in diesel cars imo. You want the engine to get warm to br efficient and the exaust hot for the dpf. Great idea if you had a 3L petrol.

Its annonying on the audi you have to turn it off for every journey.

jca

You can turn it off permanently with an Obd eleven. I've done it on my Octavia.

mickdw

It's a shocking feature on diesels. I wouldn't even like it on a petrol unless it's some form of hybrid that can move on electric power.

Tuco88

jca wrote: »

You can turn it off permanently with an Obd eleven. I've done it on my Octavia.

Cool i will have a look.

mickdw

Meeeee79 wrote: »

Make sure you keep the clutch depressed for long enough. Ive had same issue with my car but only a couple of times and it has been my own fault, changing gears too quickly I suppose. Only happened me at the beginning when I was getting used to the stop start.

I don't grasp how this possible with a functioning system. You press clutch. Get a gear and start moving then car cuts out again. It has to be a fault surely.

vectra

Check if the battery is fully charged.
Stop / start plays up when it is down.

jca

Tuco88 wrote: »

Cool i will have a look.

I'll have a look at more specific details later and let you know. It's just a matter of changing the voltage figure in the control unit it's easily reversed if you want it back.

exaisle

I have the S/S disabled (I used VAGCOM). I found it a pain in the t*ts to be honest and I didn't notice any decrease in mpg...I think it's a bit of a gimmick to be honest...

Cee-Jay-Cee

My wife’s 2010 Auris 1.33 petrol car has stop/start. It works quite well. It stopped working last year and about 7/8 months later the battery died and needed replacing so I guess the battery was weak and so the system prevents its use in those circumstances but since the new battery was fitted it has worked perfectly.

Meeeee79

mickdw wrote: »

I don't grasp how this possible with a functioning system. You press clutch. Get a gear and start moving then car cuts out again. It has to be a fault surely.

Just telling them my personal experience, there was nothing wrong with my car and once used to how it worked have had no issues. It can appear to start up but if the clutch is not depressed for long enough it will cut out again.

jca

vectra wrote: »

Check if the battery is fully charged.
Stop / start plays up when it is down.

It just defaults to continuous running if anything's outside the required figures.

jca

exaisle wrote: »

I have the S/S disabled (I used VAGCOM). I found it a pain in the t*ts to be honest and I didn't notice any decrease in mpg...I think it's a bit of a gimmick to be honest...

I had to disable it, at least with a manual box you have good control over it on my dsg it makes the car undriveable.