2004 Audi A4 1.9tdi won't start

EndaHonesty

I'm hoping someone can help.

I have a 2004 Audi A4 1.9Tdi that has been sitting around for about 3 months and won't start.

The battery is fully dead so I connected it up to my other car with jump leads and left it for a good 20 minutes before trying to start.

It turns over, but only very weakly and the battery drains completely again after trying.

Is the battery knackered or is there something else I can do to start it?

It's parked on the flat so a push start won't be easy, if that's an option.

Thanks in advance for any help.

CINCLANTFLT

EndaHonesty wrote: »

I'm hoping someone can help.

I have a 2004 Audi A4 1.9Tdi that has been sitting around for about 3 months and won't start.

The battery is fully dead so I connected it up to my other car with jump leads and left it for a good 20 minutes before trying to start.

It turns over, but only very weakly and the battery drains completely again after trying.

Is the battery knackered or is there something else I can do to start it?

It's parked on the flat so a push start won't be easy.

Thanks in advance for any help.

Are you leaving the other car running and attached via the jumper leads when you are trying to start the A4?

EndaHonesty

CINCLANTFLT wrote: »

Are you leaving the other car running and attached via the jumper leads when you are trying to start the A4?

Yes, I left the other car running and connected with the leads while trying to start the A4.

The other car has an earthing point behind the battery so I'm connecting the black leads to that point and the negative terminal on the A4 battery.

Is that correct or is there a better way?

CINCLANTFLT

EndaHonesty wrote: »

Yes, I left the other car running and connected with the leads while trying to start the A4.

The other car has an earthing point behind the battery so I'm connecting the black leads to that point and the negative terminal on the A4.

Is that correct or is there a better way?

Hmmmm.... I always connect the poles on each battery, but that may not be the right way to do it... you can always check the connection by leaving the leads connected on one car and glancing the free ends of the cables off each other and see if they spark.

Also I have sometimes had to rev the engine on the running car to provide more power... but that was on an old car about 10 years ago... that may not matter now...

Btw I am not a mechanic!

biko

There are different ways to do this. Maybe the "best" is to simply swap out the old battery for the fresh one from the other car. This way you know nothing else is the matter.

This is how you can connect the batteries if you want to jump more

EndaHonesty

biko wrote: »

There are different ways to do this. Maybe the "best" is to simply swap out the old battery for the fresh one from the other car. This way you know nothing else is the matter.

This is how you can connect the batteries if you want to jump more

I tried to find a good grounding point on the A4 but couldn't, do you know if there is an "engine ground" on the B6 A4?

I've tried searching online but am having no luck.

biko

Any free metal should be good.

You can even go black to black, but know the reason not to go black to black is that there could be a short with a spark when you connect that could ignite battery gas.

Wheelnut

CINCLANTFLT wrote: »

Hmmmm.... I always connect the poles on each battery, but that may not be the right way to do it...

There is a danger of hydrogen gas being discharged from the dead battery which could explore, so it is safer to connect the negative lead to another part of the body work.

CINCLANTFLT wrote: »

you can always check the connection by leaving the leads connected on one car and glancing the free ends of the cables off each other and see if they spark.

Don't do that with modern cars, you could blow the sh!t out of the ECU or other expensive components.[/QUOTE]

CINCLANTFLT wrote: »

Btw I am not a mechanic!

Neither am I

jca

CINCLANTFLT wrote: »

Hmmmm.... I always connect the poles on each battery, but that may not be the right way to do it... you can always check the connection by leaving the leads connected on one car and glancing the free ends of the cables off each other and see if they spark.

Also I have sometimes had to rev the engine on the running car to provide more power... but that was on an old car about 10 years ago... that may not matter now...

Btw I am not a mechanic!

Touch the leads off each other!! Are you mad?? Guaranteed to fry either one of the many ECU's or the alternator. With all the plastic around engines​ it's impossible to earth directly to the engine block, connect directly from battery to battery leaving the last connection to be made to the dead battery.

dooroy

If the car has been lying idle for 3 months and the battery has not been charged in that time then it may not be possible to get it to work again.
I have often found that a 'dead' battery will drag down a good battery - which seems to be whats happening in your case.
If the battery in your other car is good the best plan would be to fit that battery into the Audi and see how it goes (assuming poles etc are suitable).
The battery in the Audi may have been there for quite a while and the long layup has killed it. If you have a charger you could try charging it off the car.
How good are the jump leads you are using - a 1.9 Tdi takes a lot of power to turn it .