My intake valves are white. I guess thats normal? I expect the exhaust to be black. Why the difference between the heads? One looks fine the other has the two middle cyl all black. Those the AFM problem? Looking at the spark plugs Id say some cylinders are running lean. Some plugs were whiteish couple looked good tan-ish color. Injectors need to be replaced ? Is there more of a problem that i need to address? Appreciate the help.
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The smaller valves are the exhaust valves. AFM cylinders are 1, 4, 6 and 7. So, the two outside cylinders on the driver side and the two inside (middle) cylinders on the passenger side.
If the head with the two middle chambers that are carbonized came from the passenger side, then I'd venture to say that's a result of AFM. It's kinda strange since a common issue with AFM on the pre-2011 (or 2010?) engines is the oil consumption through the PCV system, but it mostly affected the two rearmost cylinders.
I'd have those heads completely gone through- Thorough cleaning, three or five angle valve job, inspect or replace valve guides, a cleaning shave (or more if you wanna raise the compression), lap in the valves, etc.
Best case is those two cylinders were running rich- lazy or leaking injectors or higher duty cycle commanded by the PCM. Worst case, the rings are worn and that carbon is from burning oil. Is it too late for a compression test? I did mine with the engine on the stand. Just reinstalled my heads and hit the starter with jumper cables.
Are the cylinders with the whiter plugs on the same head as with the two carbonized chambers?
