Fault Code P0012
 

I'm having my first issue with my '03 A8 after almost two years of (mostly) trouble-free driving. Let me start by saying that I'm not a "car guy" and I don't pretend to understand much of the sophisticated technology in my car, but I know enough to appreciate the style of an A8. Got the check engine light yesterday and went to O'rielley Auto to find the code - P0012 Intake camshaft position timing over-retarded. It ran slightly rough for just a few seconds on a cold Colorado morning, but ran as usual after that. If it matters, I've always heard about two seconds of what sounds like a slack chain since I've owned it when starting from cold, but I was told by a self-proclaimed Audi expert that it was normal. I believe he said it was something along the lines of a hydraullic cam chain tightener or something. After you stop laughing at my gullability, I was hoping for a couple of answers:
1. What should I expect for a repair? Is the most likely cause a bad sensor or something simple, or is this going to cost me?
2. Am I potentially damaging my engine by continuing to drive? I'm going to the dealer in the morning for an oil change.
3. (Unrelated) I have about 45k on the timing belt - what is the recommended interval for it?

Thanks in advance for your expertise.

1. It will cost you big if you go to the dealer and/or it really needs changing. The code indicates at least one observed instance of the variable valve timing system (passenger's side cam adjuster) not advancing the timing enough...not a dangerous problem, rather a performance enhancing feature. IF the cam adjuster is bad enough to change (in question at this point), dealer charges about $700 for the part, plus gaskets. The labor involves removing both camshafts on that side...you do the math.

2. Only potential damage if you hear a chain dragging metal sound at idle..fairly loud (NOT the start-up rattle sound). This would indicate a broken chain pad on that adjuster...if so, Park It.
The start up rattle is "normal", but is actually the early stages of adjuster failure...failure to hold enough pressure to smoothly adjust timing. The chain remains tight...the rattle is the adjuster itself "bobbing", struggling to maintain stability (NOT tightness). A badly failed adjuster (pressure loss) will do the same start-up rattle noise during warm idle and low rpms.

3. Many do belts at 80K miles...book says 105K miles. Belts may wear out faster in very dry climate. I live in a rather moist climate most of the time and my belt looked almost new when I changed it at about 100K miles.

Without any new noises, code P0012 once or twice doesn't necessarily mean impending doom. If it remains constant (after erasing the code), someone should check the wiring to the adjuster, before tearing down the motor.

Unsolicited advice: Unless you have money to burn or work at the Audi dealership, I would look for an independent German car garage...esp for simple things like oil changes.

Thanks, silverd2. I have been going to a local shop that I've been very happy with, but I'm shopping for another. Their prices seem to be just under the dealers. With a coupon, I'm getting the oil change cheaper at the dealership. I've been paying about $110 for a full syn oil change. I did get a quote on the timing belt and also brakes. That's what finally did it for me. They told me around $2500 for the belt and around $500 per axle to do the brakes. I know I don't want to go to a Meineke or Just Brakes, but that seems ridiculous.

Anyone know any good shops in the South Denver metro area?