Greetings. First post, and it's not of the "yay" variety...

I purchased this car used, in May of this year (2016). It had 130K on it, and I've put about 5K on it since then.
Supposedly, the timing belt was brand new (<1K miles) when I bought it.

OK, so basic details:

• Year: 2000
• Make/Model: Audi A6
• Size: 4.2
• Cyl: 8

Car has been running quite well, until yesterday. I was 2 blocks from home, and it started running extremely rough. When I pulled up to a stop sign, it tried to die. I limped it home. When it started running rough, there was no check engine light. As I pulled into my drive-way, the check engine light began to flash...which I know means bad news bears. The car is in my garage, and hasn't been started since.

I have an ODBII code reader, so I pulled the codes. Here are the codes, in order:

1. P0441 - Evap Emissions Purge Flow Faut
2. P0300 - Multiple Misfire
3. P0305 - Cylinder 5 Misfire
4. P0308 - Cylinder 8 Misfire
5. P0306 - Cylinder 6 Misfire
6. P0307 - Cylinder 7 Misfire
7. P1522 - Camshaft Adjustment; Bank 2: Malfunction
8. P0346 - Camshaft Pos Sensor A Circuit Range/Performance (Bank 2)
9. P0302 - Cylinder 2 Misfire

I've worked on Japanese and domestic cars before (and even rebuilt a few), but this is my first Audi. I would prefer to diag & fix this myself, but at the moment, I'm worried that I may be out of my element.


So, I have 2 questions:
1. What is going on with my car? Is the timing off, or is it something else?
2. How much is this going to cost me? If I DIY, and also if I tow it to a dealer?

 

Flashing Check Engine light isn't THAT bad. It's the misfires causing it. It could be the cam shaft sensor on that side (drivers side in the US). However, since you said the car was running fine and all of a sudden starts to run crappy leads me to believe it is simply the cam sensor. They are about $50-60 (Bosch units) and take about 30 minutes (if that long) to replace. The one on bank 2 is located at the back of the valve cover on the drivers side. You'll need a T30 Torx socket to undo the 3 or 4 bolts. Simply unplug it, unbolt it, and bolt in the new one. Reconnect and you're done. If you replace it, clear the codes on the ECU and fire it up. If the misfires go away, that was your issue. If not, then it's possible that the thing could be off a degree or two on the timing. That's not such and easy thing to fix.

Having just changed the cam chain tensioners on my 4.2 A8L, I can tell you it's not job for a beginner. I've been working on cars for 30 years and this thing really tested my ability at times. But I was able to get it right after a few setbacks that required me to disassemble things to be sure they were right. 40 valves is a lot to bend. LOL Anyway, you really need to get the Audi (Bentley) Service Manual for those cars. You'll also need to pick up the crank lock pin and cam lock bar at minimum to insure the timing is correct. The cam belt gears are not keyed like most engines, they sit on tapered surfaces on the cams and must be popped loose and allowed to spin freely when setting the timing. This allows for extremely minute adjustments when tensioning the belt.

There are a couple or three Youtube videos showing how to do it but they do not show everything in the process, just the highlights. You must follow the tensioning sequence to the letter or risk trashing the engine.

The first time I had the timing belt changed on mine, I took NOT to the stealer.....er....dealer. Instead I called a known reputable shop about an hour away. I drove it down and dropped it off. Picked it up 2 days later and it cost me about $1200. Since I did the cam chain tensioners, I'm comfortable doing my own now. I did not replace the belt tensioner and all associated rollers or the waterpump and thermostat this time but next time I will. I estimate it will cost me about $400 in parts. Should you take it to the stealer....er....dealer, it will easily run over $3000 easy.

Since you do have mechanical experience, this car should not scare you. It is a little more complex but nothing a competent and careful mechanic cannot work on in his own garage.

Anyway, swap out that cam sensor and see how it goes.

Here's the one for mine. Yours will be identical.

02 2002 Audi A8 Quattro Camshaft Position Sensor - Engine Mechanical - Beck Arnley, Bosch, Spectra Premium, Standard Motor Products, Walker - PartsGeek

 

First, I want to thank you for post. It got me going in the right direction.

So, I replaced the camshaft sensor. It was pretty easy to do. Once I replaced it, I cleared the codes, and started the car--immediately, it was back to misfiring.

I pulled the codes, and now I am only getting 6:
5 are misfires, same as above.
The other one is P1391. My code reader doesn't have any details on that code, but according to my GoogleFu, that means Camshaft Position Sensor Bank 2 Short To Ground.

Does this still mean my timing is off, or can I assume that this wire is messed up somewhere? I checked the connector plug, and I didn't see anything out of the ordinary, but I'm not completely sure where to look, other than that one plug.




ETA: Not sure if it matters, but I just noticed my battery is pretty low. Apparently I left the trunk open all day yesterday, and the dome light drained the battery. I'm charging the battery right now. I don't know if this is part of the problem, but since I don't know what is/isn't diagnostically relevant yet, I figured I would add it.

 

OK. So, I looked up the pins for the camshaft sensor plug. There are 3 pins, and according to this post, here is what they are:

• Pin 1 - Power from ECU
• Pin 2 - Signal Return from Sensor, to ECU
• Pin 3 - Ground

I pulled out my handy digital multimeter, and checked the following:

• Pin 1 to Pin 3 - 5.0 volts
• Pin 2 to Pin 3 - 11.5 volts

I went ahead and pulled the plug from the other camshaft sensor, and received the exact same values.


At this point, I'm thinking I may have received a bad part...well, let me say I'm hoping I received a bad part. Of course, this might all be completely irrelevant. As always, any help is appreciated.

 

It very well could be a bad part. Try another and see what happens.