Confirm my VCG/multiple misfire hypothesis

[lo_jack]

I had been noticing some rich/oil smell in the exhaust on my 3.0 lately, and the idle got rough over the past week. I pulled the plugs and they were literally covered in oil on the backside and burnt oil covered the tips.

I finally got p0300 and a variety of single cylinder misfire codes on startup/ first idle (p1345, p1350, etc). After the plug swap, I still got the codes and it nearly died on idle, but I gave it some gas and it started running ok.

Letting the motor get up to temp, I drove it around for a while. I cleared the codes and the SES did not come back, nor did the codes or misfires. It felt a bit more torquey in 4th and 5th.

My guess is the VCG that seals the plug tubes are leaking like a sieve, and that eventually killed my idle and caused misfires and that if I change those, my idle will clear up as I will have less oil on the plugs.

I checked every thread that had p1345 in it because that was the first code I got. Some people were dealing with cam sensors and trying to diagnose coils going dead, but I don't think I have those issues.

Would anyone disagree?

Fortunately VGCs are cheap so the test of my theory is low cost.

[Weasel]

When the valve cover gasket leaks oil onto the back of the plugs it is just that... on the back of the plugs. It can cause a misfire by the spark jumping from the boot through the oil to the head (which you would notice when you pulled your coils out if the end of the boot had oil on it) vs across the plug gap. But that oil can't physically make it to the tip of the plug in the combustion chamber... so if the plugs were covered in oil it was either from a lifetime of driving, or you're burning off a bit of oil.

How many miles you got on her?

[lo_jack]

125. That being the case, that may be PCV oil. I'll have to check that. Of course the oil that drained down into each chamber as I pulled the old plug probably didn't help. Those plugs I pulled were Bosch +4s, and they had to be 50k miles old.