Flashing Battery Light Under Hard Acceleration

[paulious]

Hi,

So I bought my 54 plate 3.2 Manual a year and a half ago. After 6 months or so it occasionally would stall when coming to stop at a junction, sometimes the TC light would come on minutes before a failure. Managed to get it home everytime by keeping the revs above idle all the time (makes for some rather interesting driving!!). On the 5 or so occasions it would be fine the next day. So, went off to halfords and bought one of their big calcium batteries. All was fine with the world for another 6 months then it happened again. During the whole time of owning the car i've noticed that sometimes under hard acceleration the battery light would flicker and it's never ever turned over quickly, theres always been a slight hesitation which i've ignorantly put down to the fact it's a big block to turn over.

So arrived at work last week in the freezing snow after just a 10 mile drive and noticed the rad fan was at 100% when I got out. That must have stayed on all day and killed the battery so jumped it, took it to Audi and asked them to replace the 2 rad fans because teh sensors are built in to them. £360 and that problems fixed but they told me my battery is weak. Really?? a 6 month old Bosch battery has given up?? Now all I can think is that I only every do my commute to work in this car (12 miles each way) and pretty much always have the heated seats and A/C on, let's face it the MPG is terrible anyway so i might as well be comfortable!! Have Audi designed this car so badly that having that load on the car for regular short journeys will always result in the battery dying in a short period of time?

I've not been lazy and just posted this, i've done a whole raft of research with the following possibilities.

faulty ground wire somewhere
slipping alternator belt
faulty alternator load signal cable(on the front of gearbox)
faulty diode in the regulator sending only 2/3 of the normal voltage to the battery (AA have checked the alt voltage and they said it was all good)

Any help would be much appreciated as this car is bleeding me dry! £3000 in maintenance and repairs in little over a year and a half: should have bought a 1litre Lupo and gone to Barbados instead!!

PS worth mentioning it has had full service with Audi 8 months ago and they replaced all the coilpacks as a recall for free! so check to see if you are eligible.

 

[ex911driver]

I would get it scanned first off. 12 miles isnt much really if you are putting a lot of load on the battery.
What has cost you £3k in maintenance ,if you dont mind me asking?

 

[paulious]

Hi,

Thanks for the quick reply. When it first stalled I called out the AA and they found camshaft sensor was faulty but he said that would have been caused by low battery screwing with sensors. He cleared the codes and told me to give it a quick blast down the dual carriageway and come back. No codes returned. Audi did their health check after replacing the fan which i assume means they checked for codes. They've reported nothing.

Maint costs so far off the top of my head. 4 tyres @ £150 each. Rear Brake calipers and discs @~£700. Full Audi Service @£600. New Radiator as bottom had rusted out @ £370. New Battery @£120. New Radiator fan set @£360. Audi advised last week that the front discs are worn and wanted £470 which i've told them not to do as the discs and pads were replaced just before I bought it.

 

[Ste_Nova]

Hi,

Thanks for the quick reply. When it first stalled I called out the AA and they found camshaft sensor was faulty but he said that would have been caused by low battery screwing with sensors. He cleared the codes and told me to give it a quick blast down the dual carriageway and come back. No codes returned. Audi did their health check after replacing the fan which i assume means they checked for codes. They've reported nothing.

Maint costs so far off the top of my head. 4 tyres @ £150 each. Rear Brake calipers and discs @~£700. Full Audi Service @£600. New Radiator as bottom had rusted out @ £370. New Battery @£120. New Radiator fan set @£360. Audi advised last week that the front discs are worn and wanted £470 which i've told them not to do as the discs and pads were replaced just before I bought it.

ouch, learn how to fix your own car

 

[NHN]

Lets be honest allot of the costs are wear & tear, so it cant be put on the one fault, general usage of a car thats now 9 years ld, is fair imho, not great for you which I understand, but certainly not unwarranted if the parts are worn.

As for the issue at hand, well have you actually had it diagnostically checked with vas or vcds & with a multimeter to check loads when locked, unlocked, in usage etc, alternator voltage/current has this been checked to see if its outputting properly?

 

[paulious]

I'm a software developer with absolutely no mechanical skills whatsoever, the wheels would end up falling off if i touched it!!

 

[paulious]

Lets be honest allot of the costs are wear & tear, so it cant be put on the one fault, general usage of a car thats now 9 years ld, is fair imho, not great for you which I understand, but certainly not unwarranted if the parts are worn.

As for the issue at hand, well have you actually had it diagnostically checked with vas or vcds & with a multimeter to check loads when locked, unlocked, in usage etc, alternator voltage/current has this been checked to see if its outputting properly?

Yeah I expected it to be high running costs, my own fault really. Still think i'm going to Japanese next time with all the reliability issues i've had in the past with Audi's.

The AA man had a code reader that is all i know. It will be going in to Audi again this week where i will ask them to do a full systems diagnostics. While my mechanical skills are terrible my electronics knowledge isn't too bad. I've checked the battery voltage as 12.7 and with engine running and under load from heated seats and A/C compressor I was getting a stable 14.4V.

Really I was just hoping that someone on here had exactly the same combination of symptoms and they had definately found the fault. Most posts talk about all the possibilities with no solution found as the fault is intermittent.