2005 Audi A6 4.2 rough idle at low rpm / sputter near rear top of engine.
 

Hi guys/ and gals,
Against most people's better judgment, not mine due to love for these machines, I picked up a 2005 A6 4.2 with some mechanical issues. Right now I am focusing on the rough idle at low rpm issues. I have opened the hood and have listened for any type of sounds, so far I only hear what I would describe as a sputtering sound coming from the rear of the engine, sounds like it may be coming from near the top, but it is hard to narrow down. Wanted to get some ideas on here of what to check for, troubleshooting tips, and resources to help with the fix. I appreciate any helpful responses. Also, anyone know what the wheels came from? Thanks!

[IMG]https://i.postimg.cc/hQbh54th/My-A6.jpg[/IMG]

Welcome to the forum. BTW, I'm in Seattle as well.

As for the issues you mentioned, are you certain the air intake is clear and do you have everything sealed up correctly? Have you done any maintenance on the vehicle: plugs, coil packs, filter changes (air, fuel, oil, cabin)? Lastly, a VCDS log with the issues would be ideal to really help troubleshoot.

Hey, thanks for the response!!!!! I just got the car Friday from someone that was very vague/had little information on the car, appears it was purchased at auction due to mechanical information. At this point I have done very little to the car. Trying to get someone over to do a VCDS log, fingers crossed mechanic friend gets over tonight. What I can tell is the car is VERY clean inside and out, appears it probably came from a dealership which did not want to invest in it (just a guess). I will keep you posted on what I find out and the log once I get my hands on it. Thank you!!!

Another quick question. Would timing chain guides be a culprit, I know the b6 s4 had ridiculous issues with this, do these as well (I am assuming its basically the same engine?)? I am ready to rip the car apart to revamp the engine but would prefer not to. Currently, have 130K on it, but it is an immaculate car, just some mechanical issues.

Mechanic buddy was over last night, he is pretty confident it is bent valves and possibly timing chains and or the guides. It was showing misfires on bank 1-5, he seemed pretty certain it was definitely valves. Going to buy the manual and start removing this engine from the car, looks like I am in for a little project :/.

If you've actually got bent valves and need to do a full timing chain and guides fix, that'll cost you more than you paid for the car.
https://www.europaparts.com/timing-c...d-4-2l-v8.html

Then I would have a rebuilt engine with quality parts. This is the plan at the moment. I hate to part it, it's too nice and fully loaded. You think this is bad idea?

I'm the wrong guy to ask about "if it's a bad idea"....have you seen what all I've done on my C6 4.2? I've dropped a sizeable amount of money on the vehicle, so wouldn't be the best sage of wisdom. I personally really like the 4.2 motor and the C6 offers a GREAT driving experience, especially once you refresh the struts w/coil overs and put in proper sway bars.

The readings from last night, looks like 5 cylinders are misfiring.
https://cimg2.ibsrv.net/gimg/www.aud...f5916db1b3.jpg