Exhaust Soot - 2013

Been noticing excessive soot build
Up lately near exhaust - any ideas? Have 300k on truck - it’s flex fuel and I am constantly resetting alcohol density- not sure if that’s causing issue of something else

 

What type of fuel are you running consistently?

 

That could certainly be the issue. If your truck thinks you are running higher ethanol fuel, it will pump more fuel in to the motor and run rich (ethanol is less energy dense than gasoline so it takes more volume to make the same power). That could soot the exhaust.

I’d also look for any oil consumption just to make sure is not burning any excessively. But usually that leaves a film that can be harder to clean off compared to soot.

 

Oil level has been good and doesn’t appear to be burning any oil -

been running regular 87 octane (10% ethanol) mostly from circle k

 

I think we all have soot similar to that, but that it stands out more on the white paint vs. other colors. My truck has soot build up there too, maybe a bit lighter than yours, but I definitely have it. I only use 91 octane and mine has 44K miles, and it's not a flex fuel engine.