Please Help A3 Turns off while idling :'(

[londonguy123]

HI! guys im new to the forum so im not sure if i am posting in the right place

i have a audi a3 X reg Auto

the car drives fine no problems while driving

but when i am at a traffic light and idling the car turns off it self and doesnt start again

the only way to start again is by jump starting

can someone please advise me on what the problem could be??

the battery is quite new changed it in 2011

[zollaf]

when you say the car turns itself off i presume you mean it stalls and the dash lights (charge, oil pressure ) come on. then it wont start, does it crank over or not, does anything happen ?
welcome aboard as well.

[londonguy123]

yeah it stalls
the lights come on and go off as if the battery is fully dead but its not
it doesnt crank over
the only way of getting it to start is by jump starting

[zollaf]

ok, so from home before a journey, does it start normally without a jump ?

[londonguy123]

nope il have to jump start it

only starts normally without a start if the car is off for longer than 5min

im not a rich guy or anything i cant really afford to go garages and get ripped off etc..

[A4 Lad]

Get yourself a good garage and you wont get "ripped off"
As far as your car problems are though, check your battery with a tester, check your alternator charging rate with a multi meter, check your earth wires and check your wiring to and from the alternator. If you are unsure how to do this, your local garage will probably do it for very little expense and give you a quote

[londonguy123]

thanks A4 LAD il try that

hope others can rub some light on this too

[NickPicks]

From your posts, I'm not sure what your problem is. You started with "It stalls", then "It'll only start with a jump start", then "It'll only start without a jump if it's off for longer than 5 mins".

So, From "It stalls", I'd have suggested cleaning the throttle body, or the idle stabilising valve (If it's got one - you need to tell us what type of engine it is (there's a 3 digit code on a sticker in the spare wheel well, it'll be somethign like AGN). A fault code read would be a good idea to see if the engine management can tell us anything helpful (This'll cost around £30 from a decent independant garage)

It also sounds like you have starting problems. If it doesn't then crank over, it's either that the battery is flat, or there's a problem with getting electric to the starter motor, so as A4Lad said, check the wiring. Halfords will test the battery for you for free with no obligation to buy a new one from them.

Does it start OK when jumping from another vehicle - this would make me think that the battery is flat (so it's then either a duff battery or the alternator is not charging). Use a voltmeter to see the battery voltage when the engine is off (ahould be about 12 volts) and when it's running (should be around 14 volts).

[londonguy123]

@NickPicks the car will turn off e.g. stall while idling... the car at this stay will only turn on from a jump start... at this stage if i turn the key there is no crank.
if the car if parked up and off for longer then 5/10min it will only start from a jump start and the only way i can enter the car if by unlocking the car manually
the car starts fine when starting from another car or from a jump pack
i did a fault code checker on the car and no codes where found.
i will take the car today to halfords to get the battery tested.
i will let you know soon what type of engine i have

thanks

[NickPicks]

Well, if it starts from a jump, but won't crank on it's own battery, I'd say that the battery is flat and not taking a charge so it's either:
- the battery is dead,
- the alternator is not charging (although then I'd expect the red battery charge light to be on)
- or possibly both of the above