Gary19966 months ago

Once the engine is running take voltage reading direct from the back of the alternator to the engine earth - should be 14V +

petHead5 months ago

Thanks for your replies.....unfortunately the car is still with the garage and they haven't looked at it yet due to prior commitments? I will advise them of the immobiliser issue because that sounds most likely ( fingers crossed ). I raised several concerns about the 120amp versus the 150amp and I was advised there shouldn't be an issue??

R2_Amazeballs4 months ago

It looks like I need to investigate this further as the info on here definateley contradicts what I have been told by the garage? One for the new year.............

R2_Amazeballs4 months ago

3 - Bad +ve terminals (search for Figure11's posts on this)

Porker4 months ago

Then take a series from alternator to chassis, across battery ect. they should all be with .1V of each other. Any big deviations and you have a poor connection.

Pete_W4 months ago

150-120 = 30 which is 20% less. Whoever told you a 120 gives almost as good as a 150 doesn't know his amps from his ar*se! LOL

MDG Ltd4 months ago

Try jump starting with a known good battery at the front with the earth jump lead clamped to the engine.

FordOwner4 months ago

This car needs a lot of amps from time to time.

MechExp4 months ago

Finally got my car back on Thursday - after much investigation this is what I have been advised.

Red4 months ago

As soon as I know more I will update.............

Bri19874 months ago

We would love to hear your feedback and any suggestions you may have for our new R8talk.com store.

R2_Amazeballs4 months ago

I jumped through a lot of unnecessary hoops before I found my earth fault.

petHead4 months ago

Let us know if there is a color option you would like added or a particular merchandise item you would like to see in the store. Have you had a chance to buy an item from our store? Then we want to hear what you think about the merchandise you bought.

Pete_W4 months ago

Firstly take the volts at the battery across the terminals - should be above 12v if battery is good and fully charged.

Red4 months ago

The A8 was transported to the garage and a 120amp alternator was sourced and fitted but now the car turns over but will not start? Any ideas? Have I damaged something whilst forcing the car to the side of the road??

Matchmaker14 months ago

search forum is your friend;fuel pump repairs here, http://www.tyresmoke.net/forum/audi-a8-s8/120276-fuel-pump.html

Corrie19994 months ago

When the original fault with alternator / battery happened I have damaged one of the pumps in the fuel tank. Due to the tanks horseshoe design ( ? ) the pump that drives the fuel over to the other side has ceased to work ( reasons unknown ) which now means I have to ensure I never drop below the half a tank mark or my engine will cease to receive fuel.

MDG Ltd4 months ago

However alt output has not got not a lot to do with the non starting but the demise of the old one may have upset the computer somewhere.

Red4 months ago

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Gary19964 months ago

Then earth on engine - should be no voltage drop. If there is then check the engine earth strap, clean all the terminal and recheck.

Gary19964 months ago

I think you are being fed a load of bull! :mad:

Fionas_Boy4 months ago

I have left it with the garage over the weekend. Apparently the car is trying to fire up but just keeps turning as if no fuel or no spark?

FordOwner4 months ago

There are 2 accesses to the fuel tank from the boot. All repairs to either side of the fuelsystem can be conducted through these. My Elsawin is not working atm but I'm sure someone can have a look and post the repair process. You don't need a new fuel tank. At worst a new pump assembly, but you may get away with just some components.

Corrie19994 months ago

No voltage at the alternator and the thing is duff.

Fionas_Boy4 months ago

Basically you will upset the balance in the electrical system. At peak the car is expecting around 150, gets only 120 - something has to give!

Corrie19994 months ago

Audi A8 alternator fault

- www.vwaudiforum.co.uk - www.vwaudiforum.co.uk -

Matchmaker14 months ago

So, with a full tank, your car is fine. It starts and runs?

petHead4 months ago

If you would like to provide feedback/suggestions please post in here Forum Threads

Porker4 months ago

had something like this happen to me when i fitted a new alternator to a 2.8 facelift d2 of my friends.

R2_Amazeballs4 months ago

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Fionas_Boy4 months ago

Get it on VagCom and you will probably learn what's up.

Matchmaker14 months ago

I asked for an estimate to fix and to replace the tank ( is the pump part of the tank ? ) and the supply and installation price was over 2000pounds plus vat !?!?!?

R2_Amazeballs4 months ago

Question: Is there an alternative fix to replacing tank and pump? Has anyone had similiar problems and can point me in the right direction?

R2_Amazeballs4 months ago

your fuel pump WILL die SOON! mine did the same about a week prior to giving out completely...

Col Minessota4 months ago

You can get by with a 120 Ah alt but it will struggle on a cold morning with all your heated seats, full beam and so on.

MechExp4 months ago

The 120 amp alternator supplied is supposed to output very near to the original 150amp that was on the car ( Im not a techie ). I will know more Monday.......

MechExp4 months ago

I'd say to be careful with the 120A Alternator. Your car probably has the 150 fitted for a reason. a8parts will probably be able to get you a used replacement that's the same model as yours.

Fireboy4 months ago

In the end you can bowl out a few issues with a volt meter.

Fireboy4 months ago

i just put some more pics here yesterday, Fuel pump assembly knowledge needed... - Page 2 - AudiWorld Forums

MDG Ltd4 months ago

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Watergirl3 months ago
This problem has been solved

- see solution here