Hey guys, it's me again. So I posted not long ago about getting misfires still after replacing my coils a couple weeks ago and my plugs about 6 months or so ago.

So one of the things I was told to check, was to make sure the plugs weren't going bad. I asked if that was something I should worry about since the plugs are only about 6 months old and I was told to just check them. So I pulled all four of the plugs.

Here's cylinder 1: https://i.imgur.com/bTjZ2su.jpg
Here's cylinder 2: https://i.imgur.com/HiXWY5n.jpg
Here's cylinder 3: https://i.imgur.com/0ubsrwA.jpg
Here's cylinder 4: https://i.imgur.com/EzBE7z4.jpg

As you can clearly see, cylinders 1 and 3 have some crap on them. Cylinder 4 looks like it's got some gunk on it too. I'm getting consistent CEL's for misfires in cylinder 1 and 3 and an intermittent CEL for cylinder 4.

The thing I noticed, however, is that there was a little bit of oil on the plugs when I pulled them and that seemed wrong to me. Did some Google-Fuing and it seems that that is the beginning to what can be a huge, engine destroying issue. So my question is, am I most likely getting my misfires due to oil being in the spark plug wells and on the plugs themselves? Would I be right in assuming that I should go get the seal's replaced and I, hopefully, should be good to go?

If this ends being it, I'll be incredibly happy that I don't have to drop a grand or more down on a HPFP.

You guys rock. Thanks for all the advice and help over this last year with the car that I may as well name "The most fun money pit ever".

 

 

I'd recommend several tests.

1. Fuel pressure check
2. Compression check and a leak down test if all cylinders aren't within 10% of each other.
3. Ignition system tests.
4. Fuel injector tests.

In my experience, an intermittent fuel injector caused a recurring cylinder 2 misfire.

 

Did you first encounter misfiring upon cold start only and then later on, it worsens into misfiring all over? Mind did that and gladly I caught the observation and got on top of it, it was due to a failing/failed High Pressure Fuel Pump at 102k miles. While I was doing the HPFP replacement, I also took out the injectors and sent them off to a shop to clean the injectors up and re-establish equal spray pattern. After I put everything back together, car runs strong like it was new. (I also did a timing chain job about 500 miles before the HPFP ordeal, so that could have helped).

Other than that, if you've replaced your plugs and ignition coils already, basing on looking at what you pulled from the plugs, you could have very badly gunked up valves due to oil recirculation (proverbial term used throughout the internet is carbon build-up), very notorious with our N14/N18 motors with direct injection. If that's the case, walnut blast will be the way to go.