Alternator Bosch or OEM Volkswagen

The part # for the Alternator (Automatic trans) is 6H903016L and it's made by Bosh. [Europaparts](https://parts.audiusa.com/p/Audi_2012_A4-Base-Sedan-20L-AT-Quattro/Alternator/48001649/06H903016L.html) sell's it for $499.95 (OEM).

The alternator was dead (as expected), and was replaced with a used one that I sourced locally from junkyard.

I changed out my original Valeo alternator with a Bosch unit at 100k miles. Never had a problem with either one.

I bought a Bosch reman for my X5 about 3 years ago, no issues whatsoever.

I'm guessing you could be Australian the labour charge would be somewhere between 120 and 150 per hour plus parts which retail close to 550 for a good quality Bosch unit so your not too far off the mark with the quote.

I have only rudimentary experience working on cars, but I got the OEM Bosch for like 300 (less core return deposit after I mailed back the old core). Took me about an hour or so to replace myself.

I tried to correct with a new and proper group size battery - it had an OE 140A Bosch alternator and starter with a 2016 El Cheapo battery that was one group size too small so I replaced the H5 with a new H6 group and all was good for a few days... I also replaced the starter just because I like to spend $ and wanted a clean slate as this a vehicle I intend to keep and drive daily as needed. The new battery/starter work great but I noticed right away that the voltage while at idle was now almost a full 2 volts lower than before changing any of the afore mentioned parts. I have a P3 dash vent gage that reads to 0.1V and I use a VOM plus VCDS so I know the P3 reads OK. Before changing any parts the P3 read 13.5 to 14.4 volts steady depending upon what accessories were on. After the H6 battery the P3 read 11.5 to 12.5 volts under the same driving conditions. I tried to get the OE alternator bench tested but that did not work so I just went with a new reman Bosch unit. No change in voltage with the new alt... So this past weekend the motor fired up just fine and the dash vent P3 gage display was 12.5V but while driving around town running errands the voltage kept dropping all the way down to 9.0V which caused the DSG to lock and basically leave me stranded miles from home. I will try to get the entire electrical system load tested this weekend but for now I just keep a tender on the batter at night as I do not drive much during the week nor do I commute. The tender keeps the battery at 13.0V reliably.

I just bought this car and I was about to replace the alternator belt but realized it’s not aligned. From this prospective the alternator is too far to the right

Ive had a few Bosch reman failures lately at my shop as well, although they were for N52s, all bearing noise after about a year.

Symptoms: Flickering lights, and occasional hiccup start. Now battery light is coming on and staying on. When stationary battery tests around 12.5 volts. When running, that drops to 11.7 volts.