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Black soot in tailpipe...MPG issues

5.8K views 20 replies 13 participants last post by  outpost4  
#1 ·
Another 2 weeks to the 1st anniversary of my 2005 (14,500 km). The best mileage I've ever had was the first tankful. I suspect the dealer added some octane. I noticed some time ago that the muffler tip was caked with black soot....an indication of a rich gasoline mixture. It's going to the dealer Monday. When I was at the dealer yesterday, the service guy said he had never heard of black soot at the tailpipe. He refused to even check it out. My Element was within his sight. He told me a I needed an appointment. I've attached a pic as proof....they may just wipe it off the tip on Monday.

Any suggestions as to the cause?.....my guess would be a computer problem.
 

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#3 ·
Element5 said:
When I was at the dealer yesterday, the service guy said he had never heard of black soot at the tailpipe. He refused to even check it out. My Element was within his sight. He told me a I needed an appointment. I've attached a pic as proof....they may just wipe it off the tip on Monday.
As has been discussed before here, you are running into the difference between a service writer, which is what the counter service guys are, and the repairman/technician, who would care about the soot. All the service writer is interested in doing is setting up your appointment, which he did. Such is the way of car dealerships, not just Honda.

Any suggestions as to the cause?.....my guess would be a computer problem.
Way too little information here for you or us to guess. I'm not even convinced there is anything wrong with your car.
 
#4 · (Edited)
All gasoline cars develop black soot at the tail pipe. Generally, it occurs in the first few minutes of startup before the catalyst gets hot and the choke is on. (Rich fuel, cool tail pipe causes the condensation of the water and the soot is attracted to it.) It is common and nothing is warranted to complain about. NORMAL. Mine is the same. The only reason you noticed it at all is because of the chrome finisher.

The first tankful being the best mileage? I'd suspect the driver to have that culpability. What mileage are you getting?
 
#7 ·
Judging from the pic it looks like an accumulation over time. Especially considering the way the outside of the tip looks. I'd say it's more from the flow of moisture out the tip with it being concentrated along the bottom edge. Now if it were extremely sooty black along the top of the tip then yes I'd say you'd have a problem. Your tip however appears to be fairly clean along the top edge.
 
#12 ·
I have 4k miles on my E, and every time I wash the car I just wipe the soot off. Every car I have ever seen with chrome around the tip shows the exact same thing. Cadillacs and their 7 inch wide dual tips are always black all the way across the bottom edge. Also many cars with dual tips have a tendency to not exhaust much air out one tip(less restriction) and thus have one clean tip and one sooty tip.
 
#14 ·
I've been driving and tuning-up cars for the last 36 years. My cars are always tuned perfectly...2X a year. Never have I seen black soot like this at the tailpipe in any of my cars. They've always been clean with a little water dripping out when running.

Element stats:
49 tankfulls of gasoline
8958 miles

City average: 16.9mpg (25mpg)
Highway average: 21.5mpg (31mpg)

Brackets are the Canadian Govt. milage rates: Imperial gallons http://oee.nrcan.gc.ca/transportation/tools/fuelratings/ratings-results.cfm?attr=8

Does my mileage suck? The black soot is not only on the chrome tip....it's caked all then way inside the tailpipe....maybe the entire exhaust system is like this.

Hope I get it fixed....we'll be driving to Wildwood for the car show on the 22nd!!!
 
#15 ·
I just recieved my chrome finish for the tail pipe 3 weeks ago, I had never noticed the same black soot until two days after I put it on. I think that only people with the chrome finish notice the soot, but everyone has it. Just my thesis.
 
#16 ·
PirateSolo said:
I just recieved my chrome finish for the tail pipe 3 weeks ago, I had never noticed the same black soot until two days after I put it on. I think that only people with the chrome finish notice the soot, but everyone has it. Just my thesis.
Exactly. I'll restate what this is...

When you start a gasoline powered car, the exhaust system is cold and the fuel mixture is rich. (Choke on.) The water and carbon in the exhaust is routed out the rear. The gas cools, condenses, and the carbon is deposited on any cold surface along with water. The water vapor trickles out to fall on the ground. Within a minute or two, the exhaust pipe is warmed up and the condensation of the carbon and water no longer occurrs.

This is normal and it happens on all cars that start cold. It is normal. And it is completely true that the only reason you are noticing this is because of the chrome finisher sticking out there like a sore thumb and that it is horizontal. If it were tucked up under the car and tilted down, you would not notice it.

In fact, you can see this on other cars too. It is especially noticable on cars where there are fake outlets pointing rearwards... like certain Pontiac models with four outlets. Two of those are fake and light gray, but two are black with this soot.
 
#18 ·
Phil collins had the same problem.


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#20 ·
Empire said:
Phil collins had the same problem.


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I always wondered what the hell he was saying in that song.
:roll:


Confucious say: Man cannot properly compare proverbial tailpipe cleanliness without comparing how often you bathe said tailpipe.
:twisted: