I know this has been posted on here a million times, and I know it is covered under warranty up to 120,000 miles.

My questions is, how do I know if that is my problem, and that it will be covered without having to pay the insane hourly rate at a dealership?

Here are the symptoms,

• Sporadic misfires, on multiple cylinders (but at different times)
• it studders/falls on it's face on acceleration between 2k-3k rpms
• decreased gas mileage

I have seen posts where they state they have 3 different codes, usually something to do with fuel pressure. I haven't had those, just the misfire codes.

I forgot to mention, I've replaced individual coils the 2 previous misfire codes and the misfire still comes back

 

Sounds more like coil packs to me, but you said some of those were already replaced. There are multiple fuel system codes that usually happen with the cam follower failure.

You really only have two options to KNOW for sure. Pull the HPFP and the cam follower and inspect it or pay the $150 (or more) diagnostic charge at the dealership (which they will eat only if it's the covered issue). If not, they will tell you what's wrong and it's your option at that point to let them fix it and get bent over or take it somewhere else and tell them what the dealership said (last time, I gave my indie mechanic the dealership's diagnostic report).

There is also a low pressure fuel system recall/customer service action out there that involves the fuel pressure sensor, intake manifold runners, and the PCV. Doesn't sound like that problem, though. I got P0089 and they did all that, but it came back and ended up being the LPFP (in the tank). I paid them to diagnose it, but refused to pay them $1100 to fix it and took it elsewhere for about half that.

 

You really need to get some diagnostics done. Diagnostics are frustrating to pay for, but are actually a really good deal if done properly. You're usually getting the more experienced techs (at the same rate as the oil change guy) and they are putting to use fairly expensive equipment and training. I feel your pain though. The dealer here usually does an hour charge and then if it's not clear it's a big chunk more for the next "level" (3+ hours).

For my cam follower the dealer initially agreed (on phone) to check in 1 hour. I had intermittent P0089 codes and didn't bother doing further testing. In person to drop it off they insisted that it would be more, but said they'd have to do the one hour either way. Basically "we need to check the code first and then see". I was mad, which I think they took under consideration. Soon after they told me it was the follower without me authorizing any further work (I guess they did it in the hour after all?). Ironically, they didn't fix what caused the code - thrust sensor - which I replaced myself for the little money rather than dealing with them again when it popped up again a couple weeks later.

Moral of the story is that they often need some codes to dig into the cam follower. All warranty policies require an actual malfunction to be present before any warranty work is done. Dealers are actually audited and can be charged back for claims that do not follow Audi policy. Audi won't pay the dealer to go fishing for problems. But you're paying, you say? If something is under warranty, you won't pay the dealer for labor, but Audi does. You must have symptoms for the tech to act on. The dealer has to submit paper work, including the original "complaint". It can't say "fishing for warranty work"! Specific conditions must be met to approve the warranty work, and the dealer is usually on your side to make sure those boxes are checked and t's crossed in your favor (even if the 'right' codes didn't pop up, as in my case). You want them on your side for warranty stuff. Trust me.

With all that said, it seems like a great time to ask them to look into both things. Bring it in for the driveability issues but push/explain that you're very worried about the cam follower. Maybe you'll get lucky and have the warranty work done (covering the initial diagnostic) but still get to find out what the problem is, if any. You won't have much luck trying to "tell" them what's wrong, even if you actually knew the cam follower was toast.

Still hate the dealer? You still needs diagnostics...

For the price of more advanced diagnostics you could buy vag-com/VCDS. It's a really good deal. Getting the same capability on another vehicle costs big bucks. Vag-com also sells on Ebay for almost 100% of retail, so if/when you sell your vehicle (And run from VAG cars like hell!) you're likely to get most of it back after it's paid for itself several times over.

The downside is the equipment is only as good as the operator. However, if you're willing to put the time in you'll find lots of help online. Unfortunately - in my view at least - there's not a lot of sensible options in between those. Educated guesses followed by throwing parts at the problem is not a good idea, especially when so much information is a short diagnostic cable away. And a code reader doesn't count. Codes can be helpful when the same underlying problem reliably produces the same codes, but for intermittent, more complex, or less frequent problems, there's just no substitute for seeing what's going on. An independent mechanic may be able to do great diagnostics too, but they won't replace your camshaft, HPFP, etc. for free if that needs doing, so why bother?

If you must know for yourself, removing the HPFP is really not as difficult as people make it out to be. I recently had everything apart to clean the intake. The interwebs made me feel as though I'd need that stubby triple-square to get at the banjo bolt, but my regular Koken one with a longish extension works just fine coming from below. If you want to take that step I'll check exactly what worked and take a pic so you can proceed with confidence. I'd still start at the dealer before expending energy for a quite look inside.

By the way - cleaning the intake SUCKED and was somewhat backbreaking work leaning over for so long. To add insult to injury, all my work was discarded when Audi replaced my engine and turbo a short while later. Why new engine? Long story, but in the end it was covered as consequential damage from the cam-follower. See why it's nice to have the dealer on your side? I was WAY out of warranty.