Junius

Hello everyone! I just bought a Black/ Amaretto 2005 Audi A8L with 180,000 miles recently at a very good price (despite the high mileage) and I must say that I'm truly impressed! But the car does have a few problems. As far as the interior goes, everything works except the Bluetooth, the Background Lighting for the front passenger armrest at night as well as the front passenger window switch, and the sunroof. But more importantly, the 4.2 V8 engine (which sounds great and runs very smooth) has a check engine light and has a rattle sound to it. Even though this is a timing belt motor, I do know it has a cam chain and tensioners for the camshafts. I was told that it needed to be replaced as it rattles throughout startup, idle, and while driving. When I received some records of the service history, it showed that the car did through running lean codes when scanned. Any ideas? Thanks

Mister Bally

Valve lifter or loose connecting rod. Loose because of wear at either of the connecting points or loose nuts at the part that wraps around the crankshaft. Heck, it could be one of the chains between camshafts on a head. Best to use standard automotive troubleshooting techniques.

richard-tx

Tensioners are likely needed and they are pricey.. Take care of that rattle before the engine grenades. Get the check engine light issue fixed.

MP4.2+6.0

Welcome.

Net, not enough info as far as your noise type issues, which to me becomes clear even w/ the shotgun of responses so far. And I'll add more: Could be water pump bearings. Could be A/C pulley (ask me how I know...). Could be noisy/worn out power steering hydraulic pump. Could even be alternator bearings, though this one almost never seems to come up on D3's.

Need to scan it with VCDS to know why the CEL is on. If it says lean, can be a variety of things in turn--vacuum leak, secondary air injection, bad O2 sensor, failing MAF, etc. Scan will zoom in on the area. Sticky is a good place to start for an orientation, including VCDS and the variety of other things that will come up at 10 years and those miles.

Bluetooth? Are you sure you have it? Early 2005's don't, late ones do. Look overhead. If you have an OnStar button, you have the early one and no Bluetooth. If you have no OnStar button and thus do have Bluetooth, 95-99% of the posts end up being something in the set up or on the phone side. Also, increasingly posters aren't distinguishing between bluetooth for phone calls, and bluetooth for music; different and the > mid 2005 D3's only had bluetooth phone capability standard.

Junius

Thanks for the responses. Well, as far as the engine side of things, when I first start it up cold, there is a rattling sound, but idles 'smoothly'. But when it gets hot, after driving or idling for a few minutes, the car then begins to idle at 600 RPMs (which I think is quite low), the rattling sound is continuous, and I can feel some of the vibration. From what it sounds like, it sounds like it is coming from the head. I spoke to the previous owner and he claimed that he replaced timing belt, spark plugs, coil packs, fuel filter and MAF sensor (not verified) but the car still gave lean condition codes. I'll try to get updated codes in the near future. He also said that he was told by an outside mechanic that the oil pump could be failing but that was never confirmed by the dealership. Wouldn't an oil pressure light come on if it was failing? As far as the Bluetooth (phone), there is no OnStar button overhead. My iPhone recognizes the car, but it seems like the car does not want to pair to the phone (it doesn't show anything to pair in the Bluetooth section of the MMI). Does anybody no a fix for the non-operating sunroof, and front passenger side window switch/nighttime background lighting? Also, I forgot to mention that the push-to-start button does not work, only the engine stop button. Are all these electrical non-operations connected? These issues are surprising given the fact of the immaculate interior condition.

MP4.2+6.0

Again, scan the car. Everything else is figuratively guys sitting in arm chairs tossing out ideas, with the cast varying some week to week, and mostly turning over every few years now. I can too, but generally waste of time. Especially the (maybe) lean code one; current scan rather than from who knows when will quickly narrow it down. VCDS cable purchase will be cheaper than your first parts guess /throw at it if you need to go on to second guess.

If you search, you will find others who have had some wiring issues involving armrests, also coupled to lights in rear of console. Ignition push to start will show up in a scan probably. Window switch is std. diagnostic technique as already stated. Testing driver console switch and door switch (other than drivers door itself) allows you to isolate it to which switch, and eliminate motor possibilities. Again, scan may tell you more.

Oil pump, almost laughable guessing by somebody to me purportedly a mechanic; you state some of the obvious reasons, plus there is about zero practical history on the board of issues there from 10 years experience here, and a more than a dozen more with my A6 4.2 over on the C5 board back when it was more active and current. I would be looking at things like motor mounts and the torque mount before that (esp. w/ your miles), plus again the water pump, AC pulley and a variety of other things that are higher probability than oil pumps. With CEL on, it could also be as simple as a bad coil pack, worn plugs, etc. ...Scan echoes... Another arm chair guess can be the valley oil anti-drainback/check valves; low probability, but a lot higher than an oil pump I bet. Again search; I walked another board member through that one, which won't show up with codes since it is a purely mechanical part. Also really obscure as far as knowledge/experience set that is (not) out there. In that same thread, another hands on poster reply also noted the secondary air throttle plates can rattle and he had run into that on another Audi with a similar set up. If you search ...and scan...again frankly you will learn more than a survey of the arm chair responses du jour, at least until you get it more focused as far as area with the apparent issue. Well meaning responses to be clear, but there's no free ride or easy lunch to a lot of the diagnostics without some hands on work, scanning, etc.

I'll stick w/ prior phone advice. Next try a known good phone against it. I assume you are doing it per the manual; if you don't have the MMI manual, that's another need to get item. A majority of those tries (where the procedure per the manual is correct) seems to result in a trip to the Apple store. My own bluetooth on my second iPhone factory "refurb" 5S was bad right out of the store, when they replaced my prior one for a bad camera. It took me frustrating month and several cars worth of trying to deduce it had to be the phone--no one could hear me when Bluetooth connected. At the store--the flag ship Palo Alto one--I had to demo to them how phone bluetooth and A2DP are not the same when they went to test it against a std. Bluetooth music player. When they finally came up with some kind of phone related bluetooth speakerphone way past an hour later and only at my insistence, the "Genius" manager finally confirmed it. I suppose look at your MMI software version too. Audi didn't want to say much, but there was some some sense the 4140 MMI update (since superseded and itself flawed in how updating worked) was partially to deal with scads of iPhone and some other smart phone complaints, though that was more back in not ready for primetime iPhone 3 era and when Steve Jobs had an apparent fling with a W12--between his usual Merc S rides. But then I know from the board traffic in general that there a still lots of old/original MMI software versions still running around successfully and presumably connecting phones.

Panelhead

Also, I forgot to mention that the push-to-start button does not work, only the engine stop button. Are all these electrical non-operations connected? These issues are surprising given the fact of the immaculate interior condition.[/QUOTE]

Get a scan done and see what the issues are.
The key may not be "paired" for the push to start to work. Usually a drive with it in the car fixes this. I have an extra used starter button. Replaced the original rectangular one with the newer style round one.
Once you get sorted on the rattle and CEL, let me know if you need a start button.

Junius

Thanks for the replies guys, I truly appreciate it. Other than that, this car rides like a flying carpet! I think I'll own it for the rest of its life (hopefully)!

ltooz_a6_a8_q7

Welcome to the great forum where people buy broken car to fix them like new... Again, nothing is inexpensive to fix, just drive it as is and enjoy the ride. I'm sure if you want to fix everything, the cost will be as much as you would have gotten an 07+ with much lower miles.

Cheers,

Louis

richard-tx

I disagree. There is no reason why your A8 will not last at least 500,000 miles. However for it to last that long you will have to get it fixed. That rattle is a bad thing and will not get better. That rattle is not normal and if left, I beliewve it will turn into a huge problem. If it were mine, I would not drive it or even start it until it is fixed. The risk to the engine is just too great. If the camshaft timing jumps, you could wind up totaling the engine. Do you really want to risk turning that engine into scrap?

My son has a A8L that has about 350,000 miles on it. There are no leaks, no rattles, no misfires, no engine codes....no issues at all. If anything isn't right, he fixes it.

Now if you don't care if the car is junk in a couple of years, then just drive it till it quits. If you want the car to last, then get the engine rattle and faults fixed.

I have a 2006 A8 with about 102,000 miles on it. I have to replace the compressor ring and spark plugs but everything else is fixed. Here is the stuff I replaced of added since I bought it 3 months ago.

trans oil and filter change
trunk motor
soft close for drivers door
passenger door window regulator
add AMI
update MMI firmware
update Navigation
cleaned AC and sunroof drains
replace cup holder
recharge air conditioner
remove and discard K&N filter. Put OEM air filter in.
Change the oil and filter - twice.

I suggest you get the engine issue fixed and do not drive or start it until you do.