Car starts every now and then....?

[silverswish]

Ok so my 97 A3 1.6 wont start. A few weeks ago my car would only allow me to start it after three tries with the service light being displayed which may have something to do with this.

Had the RAC out and he said it was a bad battery, changed the battery and it was working up until today. Even changed the key fob battery which did allow the car to start temporarily.

I have no idea what is causing it to not fire up, it cranks but doesn't start. Also, it does usually start when I disconnect and reconnect the negative lead. I know I should use VAG to read any fault codes but surely someone has had this problem before?

Any ideas?

 

[Customboy]

Maybe u have a dodgy earth or starter motor may need replacing mate surprised the rac didn't do more checks but most solutions for them are a new battery, I had a similar problem on my golf once used to be worse in the cold turned out to be the crank sensor I hope this helps but u will get a better reply from other Audi gurus on here lol hope u get it sorted ok

 

[aragorn]

"service light"?

Describe it... these cars dont have a service light.

If its a yellow light with a car icon and a key underneath its the immobiliser light. If thats flashing or staying on the car aint gonna start.

 

[silverswish]

Sorry, I meant immobiliser light. It does go out which makes me believe that it isn't immobiliser related. It's just annoying that it will start one day and not the next.

Will check the starter motor in the morning, anything else I should check tomorrow?

 

[aragorn]

Does it go out even when it wont start though? Sometimes the reader coil can start acting up and it wont detect the key properly, resulting in the light to either stay on or flashing. In this state the car wont start (well often it will start then immediately cutout, but i dont know if the 1.6 acts like this)

If the engine is cranking (ie wub wub wub wub wub) its not the starter motor, nor the battery.

It could be sensor related, or a bad fuel relay or similar. A Vagcom scan of the engine ECU might shed some light.

 

[silverswish]

Ok, so I got in the car today to take it to the garage and it wouldn't start as the immobiliser light started flashing. However on the second attempt it did start. Took it to the garage to have the fault codes read but they either charged a ridiculous amount and said it wasn't necessary.

The guy at the garage did say that it was a bad battery and I told him it was brand new, and even though the engine cranks just fine and at a fast speed he still went on to tell me it was a bad battery.

Bought the battery from Eurocarparts for £36, surely a bad battery is not the cause of this seeing as it's brand new and seems to power the starter motor just fine?

 

[aragorn]

Its CLEARLY not the battery.

The garage you visited is full of morons, never go there again. Where are you located, somoene on the forum might be nearby and able to read the fault codes out for your.

The fact your light was flashing indicates the problem though. Flashing means it cant see the key, so as a result refuses to let the car start.

You'll probably need to get a new reader coil, or at least a good working 2nd hand unit.

In the mean time, instead of cranking the engine over and over, put the key in, turn on the ignition and wait. If the immo light goes off, turn the key to start. If it starts flashing, turn the ignition off, remove the key, put it back in the other way round and repeat the process. Repeat until it starts.

 

[hades-]

sounds like the reader coil iv had it on a few audis
its usaly the wire between the 2 parts
cheap and prety easy fit
would be better to get it on vcds tho clear codes then try to start then rescan

 

[silverswish]

Just tried again to start the car, all lights go out including the immo light and it still doesn't start. This is getting a little strange.

I'm located in Aylesford, Kent.