Gen 2 Head gasket failure? Photos included

I checked spark plugs based on rougher than usual engine starts/stops and found oil on spark plug in the second chamber from the left. So, I changed the valve cover gasket and spark plugs, didn't fix it. Now getting oil on spark plugs 2 and 3, and rough stops/starts are gradually getting rougher. It has started burning oil.

Does anyone have a clue of what to try other than replacing the head gasket? I understand it's a rare problem for Gen 2's, but does happen. I've tricple checked that the replacement valve cover gasket was seated properly

Photos (all numbering from left to right when facing the engine bay)

Spark plug 1:


2:


3:


4:



A look inside the cylinders (I'd be happy to repeat these with the spark plugs removed if that would be helpful):

1:



2:



3:



4:




1:



2:



3:



4:








Hopefully that's not an overload! I figured too much info would be better than not enough.

 

Good thought, but I already replaced it along with all of the spark plugs. That was my first line of attack

 

Just to be clear, I replaced those about a month ago and these photos were taken yesterday. Looking for advice because I expected that to solve the issue and it didn't

 

She's nearly at 200K, and I replaced the spark plugs along with the valve cover gasket about 2000 miles/a month ago. No misfires reported via OBD2. I appreciate the advice, will do!

 

Right, that was my first thought as well. Unfortunately that isn't the case here.

 

Sure did, actually. They came from a seller with 99.1% positive feedback and tons of transactions, but I suppose they could still be counterfeit. That would be really unfortunate.

Here are the ones I bought: 4PCS Spark Plugs SK16R11 Fits For Toyota Corolla Matrix Prius 90919-01240 US | eBay

 

Thank you for that. I should have known better based on the price, but the strong review history persuaded me. They do seem to be well-made fakes. The only tells I could identify (aside from the non-authorized retailer and low price) are the smaller crush washer groove and that the surface of the hexagon reveals a copper color underneath when scratched heavily. Regrettably, I did not retain the old spark plugs.

I haven not checked the PCV but may just go ahead and replace it.

 

Would like to soon, going to start with replacing the counterfeit plugs (and PCV valve since it's readily accessible right now and inexpensive)

 

Thanks for all of the input! I'm going to start by swapping the counterfeit Denso plugs for authentic ones and replacing the PCV valve, will look into COP replacements. Yes, unfortunately it has had dino fuel up until a couple of months ago when I started doing my own oil changes, full synthetic now. I cleaned the throttle bottle and mass airflow sensor very thoroughly 5-6 months ago.