Battery or Altenator?

[Aronis]

Today my battery light came on and the when I looked the volt meter was down to 10.

I turned off the a/c, radio, wipers, and the voltage climbed back to about 11 and the light went out.

Restarting the A/C (hot rainy day) and wipers resulted in the voltage drifting down to 10 and the light coming back on.

I think it's just the battery giving up the ghost, but am certainly concerned about the possiblity of the altenator going south.

What do you think?

Mike

[Aronis]

Oh, when I shut down everything and left the car running the voltage did not climb above about 11, but when I began to restarted the car it was back at the middle of the guage (12) and of course dropped after turning the engine over.

[JSRS6]

Definitely has all the indications of an alternator going out. Good luck Mike.

[Elevens]

Yea I would say the Alternator is going south. Normal Voltage with minimal load should be around 13-14 Volts. So if you are not going above 12V at any time I would call the Alternator...........

[hahnmgh63]

Sounds like the Alternator of Voltage Regulator. When guys have been saying their Alternators have been going bad I wonder if it hasn't just been the voltage regulators which are bolted to the back of the Alternators on Bosch.

[JSRS6]

Either way, its time or money, or both lol.

[DHall1]

Geeee

Have we exhausted the US stock of RS6 alternators yet?

Are owners going to have to pay for shipping from Germany yet?

Mike-hurry and reserve one of few alternators left in the US. There are about 2 left in the NJ parts office.

[Aronis]

Going in Monday for routine service and suspension check (12/12000 runs out in August on DRC)

Was not planning on leaving the car but sounds like I'll barely make it there. 1 hour ride!!

Mike

[Aronis]

Do you have any contact numbers for that supplier or is it the dealer who calls??

[Aronis]

I reviewed the bentley manual, the alternator can be changed from below. Remove an air hose and move an oil line, two bolts, does not sound that bad at all. Definetely a DIY...

[DHall1]

It may not make it 1hr.

Charge the battery this weekend before you take off.

Need to contact the dealer to get the part. I think list was like 500ish


Going in Monday for routine service and suspension check (12/12000 runs out in August on DRC)

Was not planning on leaving the car but sounds like I'll barely make it there. 1 hour ride!!

Mike

[Aronis]

More Info:

Checked battery voltage car off 12 v
Started Car, checked batter voltage 12 v
looked at in car meter down to 11 (after initially being at 13)
Checked battery 12 v
Started A/C, Radio, Head Lights, In car Meter down to 10, battery voltage 12 v

So what do you think now??

I don't quite understand just what the in car volt meter is measuring? If it was measuring alternator output voltage then would that be the same at the battery? If the alternator was not generating 12 volts then the battery would drop??? Or does this battery go from 12 v to zero in a step ?

[vangelis]

That is what EXACTLY happend to me 2 months back, I bought a brand new battery from dealer and didn't fix the issue. I took it to dealer replaced alternator then only came up 100%.

[Aronis]

Vangelis,

Now that's the kind of concrete information I was looking for!

So the alternator is dying but not dead and I should be able to drive to the dealer for service, determine fault, return home, use car until part is in, go back for repair!

How long did your car run like that before it became unreliable????

Mike

[gooseleg]

Alternator, same thing happened to me last week. You do not have long as the fuel pumps will drain a battery under 45 minutes (my personal experience). Why are all these alternators going bad at the same time at least 3 posts on this site alone this week?

[hahnmgh63]

Please don't Jinx me, after 35K on my car (purchased at 25K and now at 60K), I've never had the car to the dealer except the 35K service & the DRC. As for the Alternator & Battery, the Battery fully charged should be about 13.2V (not 12V, a misnomer for a 12V electrical system), the Alternator should be charging at around 14V plus or minus .2~.5V. If you fully charge your battery you should have no problem getting a hour out of the car, caveats, during the day (no lights, no radio, no A/C, Nav Off, don't even use your turn signals unless you really need too (most Americans never bother I've found), don't use the windows, etc...

[vangelis]

Vangelis,

Now that's the kind of concrete information I was looking for!

So the alternator is dying but not dead and I should be able to drive to the dealer for service, determine fault, return home, use car until part is in, go back for repair!

How long did your car run like that before it became unreliable????

Mike

I had only few hours till I took it to the dealer for replacing the alternator. Don't expect it to last long. You better not to use anything can drain the battery (i.e A/C, radio, windows, lights..etc).

[Aronis]

Charged battery to 13.5 or so. Drove 5 minutes to get gas with no electrical items on. Volts in dash
Dropped to 11.8 or so, then generator light came on. It's definitely the alternator! No way I'm driving an hour tomorrow. Taking it to my local nonRS6 dealer.

Oh well. I'm keeping my old battery:).

[Aronis]

last little bit:

From several sources.
voltage measured at the battery with the car running should be close to 14.4, otherwise the alternator is dead or dying! The resting voltage at the battery could be lower, 12.7 or so....

aarrrggguuee

ordering alternator tomorrow, hope I get one of the last two in the country!

(torque convertor code was found tonight! not sure what that means LOL)

[Aronis]

Alternator is being replaced.

Covered by warranty.

According to service rep the car will be put in service position for this repair, although the bentley manual says it can be done from underneath the car!

So "while your there" how much for a timing belt, water pump, thermostat, and rollers etc.....$1765 MORE on top of covered service! I got a quote before for timing belt service for $1300 and that dealer will still do it for $1300 (other items adds $235 for parts - water pump $170, Thermostat $65)

So where's the savings since the car will already be put into service position???

Just having alternator done, then taking it back to RS6 dealer for the the timing belt etc after another 10,000 miles!

Mike

[JSRS6]

That doesn't sound right, Mike. It should be about half that if the car is already in the service position...

[Aronis]

Apparently they charge a higher hourly rate which effects the overall price. The other Dealer (an RS6 certified one) is standing by their prior price from several years ago! So even with the added water pump and thermostat is will be less expensive at that dealership and would be done by a guy who has done the timing belt on an RS6 before.

This is not to disparage the guy doing the alternator here in town, I'm sure he's a fine mechanic, but it comes down to cash flow and price!

Mike

[DHall1]

What a pisser. Rock and a hard place. Did you ask them for a better parts price. Its the perfect time to do the timing belt and its at the wrong dealer.

[JSRS6]

Its all about the Benjamins. LOL

[Aronis]

Alternator replaced - covered by warranty - listed as 4.6 hours of labor, part $550 (rebuilt alternator), total price $997.20
Had the serpentine belt changed, oil and filter, new fuel pump installed.

All seems fine.

But now on to the Fault Code I found when scanning - 17125 Torque Converter Clutch :Stuck off/No Power being transferred P0741 -003 Mechanical Failure...

Some have suggested this may be an erroneous code due to the low voltage.

The dealer did not mention seeing this code??? I did not tell them since I figured THEY should have and would have scanned and found any fault codes, but they did not!?!??!

I reset it and will drive a bit to see if it shows again.

And I still have the original battery in the car LOL.

Mike

[V8weight]

Glad to hear you have the car back. As for the p0741 code, is this the second time you have gotten this DTC then? Did you clear it the las ttime it came up, or is this the same code. The dealer likely wouldn't have done a full scan, they likely would have only entered the engine module to erase the low voltage to terminal 30 code associated with the alternator replacement. So it's not surprising that they didn't stumble upon this on their own. There's really no way around this though, a new torque converter is in your near future. It has to register a non lock-up condition twice before it will trigger a CEL again, so it may take some time, but it will probably come back.

[Aronis]

I did not erase until yesterday. Too bad there is no date stamp which tells you when the code occurred.

[DHall1]

Don't pay for the timing belt service yet.

There may be a tc in your future.

Start planning for it.

Don't erase any codes. The more its driven the more the clutch material floods the trans

[Aronis]

Dhall1,

Could you tell me more about the codes. You mentioned if it happens three times the CEL will come on.

I found on Ross Tech a list of possible causes of that particular error message.
This is a similar list as I canont find the link to the Ross Tech page I found yesterday (Google changes daily!, never the same search twice LOL)

Transmission Sealing faulty
Automatic Transmission Fluid (ATF) dirty
Torque Converter faulty or incorrect Torque Converter installed
Solenoid Valve 7 (N94)/Pressure Regulating Valve 4 (N218) faulty
Torque Converter Pressure Valve faulty
Valve for Torque Converter Clutch faulty
Torque Converter Lock-Up Clutch faulty/worn out

I am going to check for codes daily for a while. I wish I have more faith in a post ealier which stated that the low voltage could have caused this error message to occur eroneously, but some how I doubt it! I have several prior "scan all" logs and this was the first time I had that code and the other.

What can I expect as the TC fails?

Thanks for your help,

Mike

[DHall1]

Mike,

We are on vacation right now. My only internet is this droid. If you need a tc then the engine and trans is coming out. The perfect time to service the tb.

Pat,

Can you answer the questions.

[V8weight]

Mike, the problem with the torque converter lies in poorly designed Input and stator seals. Over time they begin to leak internally, and the torque converter starts to bleed off pressure. So at a reduced pressure, it can no longer lock up, and also starts to lose efficiency. It will start to slip, especially at highway speeds, at higher torque loads in higher gears. The whole time, this slippage is overheating the fluid, and circulating bits of clutch throughout the transmission. It takes very few miles to damage the transmission as well. You will probably notice about a 100-200 rpm increase at highway speeds. In all the threads I've seen all over the internet for various different Audi models, I've never seen this code actually caused by a bad solenoid or dirty fluid. This poorly designed TC is not limited to the RS6, it's a design flaw inherent in all models across the board. The RS6 replacement TC is an updated design. It doesn't handle any more torque, but they have addressed the seal issue. And yes, the ecu has to see 2 (or 3?) non lock up events before it will store the p0741 code and trigger the check engine light, but I wouldn't wait around to long. Your transmission is suffering as a result. Don't feel bad though, I just got my car back from an alternator replacement as well, now I have gotten a code for a faulty bank 2 EGT sensor three times. It was good to have the car back for a week. :)

[Aronis]

Pat,

I am planning on logging group 7 which shows ATF Temp, torque converter lockup status and the SLIP RPMs (should be no more than 20 rpm).

If there are no abnormal readings and the error message does not show again, then it would be very difficult to get a new TC under warranty. I doubt they would pay based on ONE reading of an error code without tripping a CEL.

I have not real idea when the first code was triggered nor do I know how the TCU keeps track of the number of times it is tripped. It may have tripped on one of out 100 degree days! I am not sure.

I have to go to Boston this weekend so I'll be doing a 300 mile trip each way, if the TC goes, it goes, my warranty will cover it!

Mike