P-Zero

Hey everyone, new guy here. Hopefully you guys can help me with my A6.

So recently I acquired an 02 A6 with around 122k miles. I bought the vehicle from the original owner with the problems that it currently has in hopes I could fix it.

So here's some info about the car and the problem:

It's an '02 A6 3.0 Quattro (4B2 AVK). The people that I bought it from only ran 5w30 non synthetic (syn blend most likely) through it.
The engine has a rattle to it when it's running (oil pressure problem perhaps?).
It fires right up every time and seems to run ok, but not great. I didn't want to rev it past 2k to prevent any further damage to the engine.

Here's the codes it's throwing:
p0300 - random multiple misfire.
p0302 - misfire cyl 2
p0303 - misfire cyl 3
I assume those are because of the camshaft codes; which are:

p0345 (16729) - Cam position sensor 2 malfunction.
p0365 (16749) - Cam position sensor 3 malfunction
p0391 (16775) - Cam position sensor 3 incorrect signal.

I've searched a bit and this seems like a fairly common issue, so I was hoping you Audi guru's could shed some light on the subject and I could get this car up and running.

Any help pointing me in the right direction is GREATLY appreciated.

x19

Hi, Your car has misfiring code and call to Audi dealer about Ignition coil recall for your car. you have to drive to them for another recall? may be. also, Do you know when T/B done?

P-Zero

Supposedly the timing belt was done not too long ago according to what the previous owner told me.

I'll get a hold of the dealer Monday and see if it was done. Although, I believe the misfiring is due to the camshaft's not being where they're supposed to be.

However, the thing that bothers me most is the rattling noise from within the engine.

I forgot to mention in my previous post that when the engine is running, I'm getting a low oil pressure(Red oil can) message on the display.

Airbag

Well that isn't good.. You may have quite a bit of engine damage already if running it with oil pressure light on.

The noise is because there is no oil pressure and your cams are running dry.

There is very little you can do without major tearing down of the motor if it is true low oil pressure condition, and based on the noise I think you do.

All you can do.Is replace the oil filter and hope it was plugged. Maybe check the oil pressure relief valve if the audi even has one.

Other than that the engine sounds like toast

I don't. Want to be disrespectful but telling us you think the rattle is because the cams are mis timed and you have no oil pressure is looking past the obvious

Your hydraulic tensioner aren't pumping up and your chain is rattling and throwing off cams.
Fix your oil pressure.

P-Zero

No disrespect taken.
This engine doesn't have a chain between the cams, the T-belt drives both cams.
Pulled one of the valve covers yesterday and it seems as though there's oil on the head, not very much, but there is some there (the car hasn't been started in about a week).
The Variable cam actuators are electronic, however, they do need oil pressure to work.
The oil was changed VERY recently by the previous owner and the correct weight and spec oil was used (Service Pro 5w40, meets even Mercedes 229.5 spec --the most difficult approval rating of ANY manufacturer out there). As a matter of fact, it's still golden since there's maybe 5 miles on it.

There is a TSB that mentions something about the bolts on the cam pulleys loosening, or falling out. And another that mentions something about the o-rings on the actuators leaking and resulting in insufficient oil pressure to actuate the Variable cam timing.
I'm waiting on the timing kit from amazon that has the crank lock pin and the cam holders before I drop the oil pan.

Also, for what it's worth, I am a certified mechanic, however, almost no experience with Audi's.

jcman

Not trying to thread-jack Airbag, P-Zero you are very correct about the cam timing system on the 3.0 and it's actually quite refreshing to read from a member who researched the engine.

As long if the exhaust cam lobes are intact "your golden" and the big concern is the low oil pressure for sure, sounds like your on the right track so far dropping the pan but after that if the results are normal I'd look into the adjuster seals and make sure crankcase vent system is clear

Good luck!

P-Zero

Hey thanks JC!
I try to find out as much as I can about an engine before I tear into them. The old push-rod/non VVT/VCT engines were fairly straightforward. All of the newer ones with variable valve train can be quite tricky. On some, if you remove the actuators from the heads, you HAVE to replace the head (Nissan/Infiniti).

I was reading in a Technical Service Bulletin (not sure which TSB #) there may be heavy wear on some of the lifters and lobes. I only pulled the valve cover off of the passenger side head (not sure if that's bank 1 or 2), and from what I could see of the lobes, they look perfectly fine. There is a lifter that may be suspect, but I have to pull the cams to verify. Most of them looked very good.
It's kind of strange that a vehicle with this many miles (122k) would have low oil pressure problems.
Do you know the procedure to check the oil pressure? I'm assuming that you pull the oil pressure sending unit and hook up an oil pressure gauge; just wondering if Audi has an official procedure to check it.

Airbag

Someone had an issue recently where they had to get under the car with the pan off and poke stuff up through the holes sounds drastic but what do you have to lose. You don't want to run it with low oil pressure

Pz sorry for misleading you with tensioner. Didn't notice the 3.0 duh.... Both cams run off belt.

jcman

Here is a pdf on that procedure before you drop the pan.

Prospeeder

Your issue sure sounds oil pressure related. Noise, cam codes oil light. Remove the lower oil pan. I have seen 3.0s fill the pan up with sludge. I also have seen the pipes running from the oil pump to the block, the o-rings fail and bleed off oil pressure. Good luck stop running it before it destroys something lol