bdm7795

Hi all,
I rolled my 2014 c300 sport over 60k recently and, according to my maintenance schedule, it was time for spark plugs. While I had the intake plenum off, I snapped a few pics of the backs of all of my intake valves to see how the PCV system carbon deposits were doing since this is a GDI engine with no secondary injectors to clean the valves.

Take a look a the pics below of my valves. I used a BMW N54 engine for a benchmark to compare the buildup to from google images. Comparatively, these valves look really good.

Regular liqui moly oil changes, 93 octane fuel.

Anyone else have pictures of their m276 intake valves at 60k to compare to?

Has anyone done a seafoam for CRC intake cleaner?

Just204

Not bad. Much bigger problem on turbo cars. What kind of driving do you mostly do? I’m largly highway so that’s better. I’m real close to the 60k mark as well.

bdm7795

I'm a pretty good mix between local and highway. Highway definitely accounting for most of the 15k miles I've put on it in the last 11 months.

Are you doing your plugs yourself?

Just204

Yah, I’m going to do them myself. No reason to pay someone to do something I can. Was going to do it the easy way but might do it that way and walnut blast the valves just for piece of mind.

Tom in Austin

That's nice, thanks for posting! Stands to reason GDI engines would have less carbon buildup since there's no injector shooting fuel against the back of the valves

kenju4u

I hit 60k miles recently on same year and model. Did the plugs and now noticing lower mileage. Would you guys recommend Liqui moly?