P0301 HG vs EGR vs valves?

I bought my 2010 new. It now has 265K, with the last 4 years only being about 15K. The last real service done by the dealer was 150K.

I've tried to help myself here by reading many HG related threads. My case doesn't seem clear to me.

It has had the cold start rough wobble occasionally since around 60K miles from what I can remember. The perfect conditions: cold outside temperature, under freezing helps I think. Move the car in the drive way from one spot to another allowing the ICE to run only for 5 seconds. Leave it over night. The next time you start, guaranteed wobbling. It never threw an error code.

I never knew to do an EGR clean out until the last few weeks as I've followed many threads now. It may have never been done. It may have been done by the dealer at 150K.

I did the paper test for for coolant spit out of the spark plug holes. I see in another thread a month or 2 ago, that this test is looked down on. I did the exhaust gas leak test on the coolant by pulling the coolant gas through the blue solution and see if it turns yellow. Also, looked down on here. Both seemed good, no splattering on paper, and it didn't turn yellow. (although after about 5 minutes it turned a blue-green)

That said, maybe below is better information.

Spark plugs:
#1 looked dirty, #4 looked almost as dirty,
#2 and #3 were not as dirty and more dry looking.
None looked "steam cleaned."

I have a cheap scope I bought for another project a year ago. It only has 1 camera pointed down. Looking down into the cylinders:
#1 looks dark wet but oily wet, kind of small shiny beads
#2 looks dry, not dark, not shiny, kind of flat gray
#3 looks dry, not dark, not shiny, kind of flat gray
#4 looks like #1 but not as "bad"
(oily grunge, is that valves?)

I had not added coolant in probably 6 years, I know it was getting lower through out that time. Noticed that it might be dangerously low when checking the P0301 and added to the reservoir. (maybe I got hot bubbles that helped warp the head?)

Before the P0301, I filled up my tank with gas -- took about 9.3 gallons. I had a rough start about 10 miles after and the P0301. (maybe bad gas? fuel filter? fuel injectors?)

I've replaced the spark plugs. I've swapped 1&2 coils and 3&4 coils. Some wobble on start still. After 20 miles, checked new spark plugs and they look uglier in 1&4 still.

I've never had white smoke or black/blue smoke out the exhaust. I've never had signs of coolant in the oil, although I haven't drained it for a change in 4 months.

Current Plan:
1. Clean out EGR and replace PCV
2. Clean fuel injectors and replace fuel filter
3. If those don't help, HG replacement and machine shop for surface and maybe valves?

I'd say HG right off, but I don't know what I'm seeing with the scope down #1. I'd welcome thoughts on this.

Thanks,
Scott

 

I just read T-SB-0010-12. That explains the cold start wobble/rough/knock. My dealership claimed they hadn't heard of that before when I explained it ~2013. <sigh>

 

I realized that my last comment was confusing. The TSB explains the long term cold start wobble/rough/knock of years past. It doesn't really explain my current problem.