A2 Won't Start - HELP!

tbc

Member
Started up my A2 1.4 petrol yesterday morning and let it run for 10 minutes all fine. Turned it off and went back inside about an hour later I went out to start it and it won't. When I turn the key all that happens is the wiper moves slowly across the windscreen (wiper stalk isn't on an won't move when moved up). Thought it might the battery so I used my jump starter and no luck. Even took the battery out and got it checked, nothing wrong with the battery. Even tried jumpstarting it from another car.

Can hear the fuel pump sound and it stops, OK on the display but when I go to start it nothing. Bizarre that it started on the button less than an hour before. Plenty of fuel in it, battery fine but for some reason it just won't start.

Left it until this morning and went out to start it and nothing same slow wiper movement, I'm stumped, has the starter motor simply failed or is it some other electrical problem.
 

Rusty911

A2OC Donor
Turn the headlights on and watch whilst someone tries to start the car. If they don't change when the ignition is moved to the 'start' (one on from run) position, suspect ignition switch, immobiliser, starter motor solenoid wiring, or possibly engine earth.

Practically speaking, I'd start with the earth: If you have a set of jump leads, you can eliminate or confirm earth by putting one or both jump leads between a metal bit of the engine to a metal bit of the car body: the right hand engine mount is a good place: just bridge between the half that wiggles with the engine to the half that is solid to the body. (This replicates the earth lead basically). Also worth lightly tapping the starter motor body with a hammer whilst someone else turns the key to start. Naturally get them to double check it's in neutral! Finally, give the little wire that goes to the starter a wiggle, again whilst it's being held in start. I'd also try to check to make sure the big leads that go to the starter are nice and tight, but you'll have to remove the cylindrical black plastic tube that covers them (held on with a cable-tie).

After that, it could be ignition switch or immobiliser issues but the diagnostics on these gets a bit harder as a quick and dirty roadside check.

Now, if the lights go very dim: suspect flat or iffy battery, or poor / loose / dirty battery leads or terminals (earth or positive). Check they look clean and they are fitted correctly and tight.

Starter motor could either leave headlights as they are, or dim them, so it's best to run through the above checks first before moving on to the starter itself. It's pretty unlikely a starter would go from working fine to having failed outright: they usually give some sort of warning, often over months or years. The only thing that could simply fail is the solenoid, hence the above tapping test: it's jiggles the contacts around and frees the moving parts, often 'curing' it for a while.
 
Last edited:

tbc

Member
Engine earth would be my starting point
I checked the secondary earth from the engine block to the wiper motor. When I disconnected I the wiper stopped so the secondary earth is working. The main earth down behind the passenger headlight will be my next thing tomorrow

. I have had the battery tested and fully charged, even tried a different battery which didn't solve it.

Thanks for the advice, I think it's either the starter which I will give a whack tomorrow or the main earth which I'll try and access tomorrow and clean and look at replacing for a genuine part from Audi.
 

Howey

Member
On my tdi i fitted an earth from engine mount to aux drive belt tensioner

A well placed jump lead from body to engine my prove its the engine earth at fault
 

dieselfan

Member
Thanks for the advice, I think it's either the starter which I will give a whack tomorrow or the main earth which I'll try and access tomorrow and clean and look at replacing for a genuine part from Audi.
A2 have a very long +cable (from the battery in the trunk to the starter in the front) so it is woundable for any reduction in cable shoe contact (corrosion) and cable breakage.
You are probably not using your A2 so often in low temperatures as I do but still useful to add an earth cable with good contact.

Cheers
dieselfan
 

tbc

Member
A2 have a very long +cable (from the battery in the trunk to the starter in the front) so it is woundable for any reduction in cable shoe contact (corrosion) and cable breakage.
You are probably not using your A2 so often in low temperatures as I do but still useful to add an earth cable with good contact.

Cheers
dieselfan

I went out this morning and it started first time, turned it off again and it started again. That was a whole day of not starting yesterday. I think it's definitely something to do with the earth as I've done the battery checks and had it tested and it was fine.I also checked the lights as previously recommended and they didn't dim when attempting to start the car.

I have an additional earth from the top of the engine block to the wiper motor then there is another wire goes from the engine block to what looks like the second coil pack, I didn't fit the secondary earth unfortunately so don't know if it was fitted because the main one is a bit dicky or just as a back up. To be honest I'd rather change the main one and be done with it if it wasn't a bit job.
 

tbc

Member
Its body to to block you need

Will that override the main earth if it goes wonky. It started perfectly on the button last night then tried it this morning and nothing. It seems to be intermittent. Can't understand why it starts one time and not the other. When it's left running it's fine, no misfire or anything.
 

PlasticMac

Member
Will that override the main earth if it goes wonky. It started perfectly on the button last night then tried it this morning and nothing. It seems to be intermittent. Can't understand why it starts one time and not the other. When it's left running it's fine, no misfire or anything.
It's the high current that starting draws that causes voltage drop across the dodgy earth connection. Once it's running, current draw is low, so the dodgy (high resistance) earth is much less of a problem. It would only get worse, dampness, vibration, and erosion cause by the energy trying to cross the dodgy connection will take it's toll. Your new earth will do all the work now, so you can forget the suspect one,
Mac.
 

tbc

Member
It's the high current that starting draws that causes voltage drop across the dodgy earth connection. Once it's running, current draw is low, so the dodgy (high resistance) earth is much less of a problem. It would only get worse, dampness, vibration, and erosion cause by the energy trying to cross the dodgy connection will take it's toll. Your new earth will do all the work now, so you can forget the suspect one,
Mac.

Thanks, looks like a trip to Halfrauds for an earth cable should do the trick.
 

tbc

Member
Really starting to fall out of love my with my A2. Added a secondary earth and it lasted a month before doing it's non starting party piece. Then it was back to struggling to start and the magic wiper going.

So about a month ago I took it to my local auto spark he took off and cleaned the main earth behind the headlight, it was starting fine until yesterday when it struggled. took me about 20 minutes to get it started without the jump lead making a temporary earth.

Should I just order a completely new earth and change the main earth completely, really starting to annoy me. It'll start and drive perfectly for a month and then become temperamental. This after nearly three years of trouble free motoring and I could really do without cleaning the earth every month.
 

kp 115

Member
Really starting to fall out of love my with my A2. Added a secondary earth and it lasted a month before doing it's non starting party piece. Then it was back to struggling to start and the magic wiper going.

So about a month ago I took it to my local auto spark he took off and cleaned the main earth behind the headlight, it was starting fine until yesterday when it struggled. took me about 20 minutes to get it started without the jump lead making a temporary earth.

Should I just order a completely new earth and change the main earth completely, really starting to annoy me. It'll start and drive perfectly for a month and then become temperamental. This after nearly three years of trouble free motoring and I could really do without cleaning the earth every month.
Hi tbc,
Not sure if it’s been checked but it has been noted that the actual cable can fail internally which is only visible if the terminal end insulation is stripped back, give the terminal a sharp tug with a pair of pliers etc.
Hth
Keith
 

Howey

Member
Is your secondary earth still fitted and which do you use?

I did a thread search starshine if it helps
 

RAB

Technical Specialist 1.2 TDI
Have you cleaned the battery posts and their connectors? Ignition switch and starter relay OK? You can easily check earths by connecting a DVM between the -ve battery post and the engine or body - reading should be low.

RAB
 

gills

A2OC Donor
I would add another earth from the engine block to the O/S engine mount. Cable is only £5 from ebay and easy to fit. This is the one I did on my TDI:

PXL_20201008_191853807-01.jpg
 

Rusty911

A2OC Donor
Have you cleaned the battery posts and their connectors? Ignition switch and starter relay OK? You can easily check earths by connecting a DVM between the -ve battery post and the engine or body - reading should be low.

RAB

^^^ ThIs: it's the only way to see what's really going on.

Get a digital voltage meter (cheap as chips is fine, nothing special). Set it to DC Volts, if it has a range set it to whatever gets you around 12v'ish (2-20, 10-20, something like that). Bonnet off, put one lead on a clean bit of engine, one lead on a clean bit of the body. Get someone to crank the car. If you see, say, much more than one-two volts, you've got an earth problem. If you see less than (say) 0.1 - 0.2, your earths are fine.

I have to say, earths are pretty unlikely to go in and out so to speak. They'll work or not work generally. Think decline rather than intermittent fully working /:completely failed.

The reason for checking the earths is obviously it affects cranking / starting, but also it's something that's very easy (and free) to do. Check, sort, forget, move on. If moving on, see my above post for other things to check.
 
Last edited:

tbc

Member
Think my many years with my A2 might be coming to an end, mines 2002 1.4 SE with 102k miles and despite having nearly 3 years reliable motoring it's become a bit of a nightmare over the last few months in that I can't go any real distance with the confidence I'll be able to get back.

It starts fine at the beginning and drives fine, but after say an hour of driving you can stop and park up to into a shop, come back out and it won't start, the wiper will move slowly across the windscreen.

Had to call the AA last time who put a boost onto the battery and after switching the lights on it fired right up. Started it everyday and it's fired up no problem, the AA guy said he thought it was the starter which I don't think it is. It has had different earths added, one to the block to wiper motor and another from block to brake fluid holder.

Charged the battery up and it starts. It is almost like something is taking power away from the battery. I have a dash cam which I pull out every time a park up and leave the car.

It went to an auto spark who cleaned the earth and it was fine for about three weeks then did it's party piece of failing to start

Just lost as to what to do. I can't sell it as it is although in great condition with 102k and the interior is mint so price it's probably worth not far off £2k. Would like to get the issue fixed once and for all and continue driving but the unreliability over recent months is driving me mad.
 
Top