Black Soot Stains On Bed And Tail Pitpe

[cwendel4]

I just washed my truck the other day. On Christmas eve I went out to load the sled for the family rounds and found carbon on the side of the bed above the tail pipe. I did move the truck after washing it but the end of the tail pipe also had carbon soot all around the inside and outside edge.

Then pulling out on the highway I had to gun it and after I was up to speed I started to smell some rotten eggs, it went away a few moments later but...... I have had the smell when going up a bridge here and there but thought a 2007 would not have bad cats yet.

 

No codes, no lights on the dash. It is an 07 with the 5.3l (LY5), 4l60e and 3.42 in the axle. I run 89 octane in NJ and find the motor has got a hesitation compared to my old GMC 5.3l. I did find the other day if I use the tow button, the new truck acts like my old 00 with a 5.3l when the tow button is not pressed.

I have to take it to the dealer for another issue and want some ideas. Gas mileage is 16.8 mpg and I do a large amount of highway driving and do drive like I have an egg under the pedal. The 2000 has gotten 17 mpg when I was real careful and 19 for a race weekend to Pocono.

I am worried I have an issue but I don't want to ask about a problem if it is normal and start having a rep.

[jro909]

the rotten egg smell is the aroma the cat gives off after you gun it...its normal....the soot may be from oil consumption, i also know direct injection motors seems to do this alot also...my tailpipe has a black ring on the outter edge of it but nothen on the paint or body itself

[Doug_Scott]

Has the weather been different recently? Like colder than it was 2 weeks ago? Be careful that you do not start micro-managing your truck. Not sure how old you are, but if you are my age you wll remember cars before cats were installed. The rotten egg (actually sulpher smell) was only on cars that were cat equipped.

[cwendel4]

I am old enough to have owned a number of cars that had carburetors and been around those without cats. I have worked on a few hot rods in my time, no cats and open pipes.

On cars with cats, the only time I have found that I should get that rotten egg smell is if the motor is running way too rich or the cats are going bad. I had a 77 pontiac mid size I bought that had an honest 55,000 miles on the clock and six months in the cats started smelling bad going up some hills and then they clogged up. had to stop the car and let them cool before I could finish driving up the hill and get to where I was going.

 

Also, the soot is not oily and gooey, sign of oil burning and oil getting past the cats. Also, no blue smoke when cold and I have not seen any when accelerating on the highway or from a stop sign.

 

I know everybody says the hesitation from a stop and when getting in the gas is a result of torque management on these trucks, I wonder if it is not the result of carbon build up.

[rockcrusherrevived]

if your tail pipe is pointing up it will collect water then you will see the soot when you rev the engine

 

 

I just washed my truck the other day. On Christmas eve I went out to load the sled for the family rounds and found carbon on the side of the bed above the tail pipe. I did move the truck after washing it but the end of the tail pipe also had carbon soot all around the inside and outside edge.

Then pulling out on the highway I had to gun it and after I was up to speed I started to smell some rotten eggs, it went away a few moments later but...... I have had the smell when going up a bridge here and there but thought a 2007 would not have bad cats yet.

 

No codes, no lights on the dash. It is an 07 with the 5.3l (LY5), 4l60e and 3.42 in the axle. I run 89 octane in NJ and find the motor has got a hesitation compared to my old GMC 5.3l. I did find the other day if I use the tow button, the new truck acts like my old 00 with a 5.3l when the tow button is not pressed.

I have to take it to the dealer for another issue and want some ideas. Gas mileage is 16.8 mpg and I do a large amount of highway driving and do drive like I have an egg under the pedal. The 2000 has gotten 17 mpg when I was real careful and 19 for a race weekend to Pocono.

I am worried I have an issue but I don't want to ask about a problem if it is normal and start having a rep.