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Thread: Excessive Sute (Black stuff)
06-10-2009, 07:06 PM #1
Excessive Sute (Black stuff)
Just got back from a 2900 mile road trip. I noticed a lot of sute (black stuff) around the lower rear panel where the exhaust exits. I got the truck used, i know it's got a flowmaster just not sure how far they went back with it. What would be the cause of the excessive black stuff?03 Suburban:
6" CST lift, 17" Mountain Crusher Rims, 35" Toyo MT tires, Fox 2.0 shocks and a Flowmaster exhaust
06-11-2009, 07:00 AM #2
- Join Date
- Apr 2009
What you're referring to is "soot," and it's made when either 1) you drive a diesel, or 2) you're running too rich. How fast do you normally cruise on the highway? Fast enough to work the crap out of the engine? It will run a little bit rich at high load, but probably not rich enough to cover a body panel with soot. Normally, you only see that with high-powered forced induction vehicles, running VERY rich, down in the 11:1 AFR range.
I think you've got a fuel metering issue. Do you know what your kinda mileage you're getting?
06-11-2009, 07:09 AM #3
good posting mateospeed. though 2900 miles is a long haul, i would almost expect to see some black. no much, but some. do you burn any oil? do you have a tune installed?2000 silverado with a 5.3l v8, shorty headers, upgraded plugs, 10 mil wires, magnaflow high flow cats, flowmaster 80 series muffler(2 in 2 out) w/ 18 inch stainless silverline tips. i have a k&n CIA. its a 4x4 z71 offroad package. Ls model.
extended cab 160k miles, truxedo low profile bed cover, diablo sport predator tuner.
reman tranny @ 130k miles
06-11-2009, 01:22 PM #4
Speed ranged from 60-75 mph and i averaged between 12-13 mpg. I have made this trip with two other vehicles and it didn't have the soot. The other two were stock though.
Not burning any oil and no i don't have a tune
06-11-2009, 04:49 PM #5
hmmmm... mow many miles are on your vehicle. you most likely running lean, but you could do a tune up. new plugs and wires, cap and rotor if you have them, seafoam, etc
06-11-2009, 05:17 PM #6
yeah good idea cascott a good tuneup and sea foam or similar product will help out your intake is probably carboned up pretty good and just needs a good cleaning up
06-11-2009, 11:17 PM #7
what year is the vehicle, is it burning oil?bd1326
2005 Chevy Silverado 6.0 Vortec 4X4
K&N Air Filter: Stock Replacement
E3 Spark Plugs
Magnaflow Single Exit Exhaust
Rough Country Leveling Kit
Much More To Come
"Understeer is hitting the wall with the front of your car. Oversteer is hitting it with the rear."
- NASCAR driver "Fireball" Roberts.
06-12-2009, 04:14 AM #8
Bought the truck with like 86,000Got 90,000 and some change on it now. I have noticed driving around the last couple days it seems to have a little more get up and go now though.
It's an 03 and no it's not burning oil
06-12-2009, 09:43 AM #9
I'm with mateospeed on this one: excessive soot is usually an indication of air/fuel mixture problems. The PCM's primary purpose is to control fuel mixture, so the first thing I'd probably do would be to put a scanner on it and see if there are any trouble codes (or pending codes). I'd probably also put a fuel pressure gauge on it and see if fuel delivery is running where it should. Assuming your '03 has the same "continuously recirculatiing" fuel system like my '98, the regulators sometimes develop a leak that will let unmetered fuel into the intake which makes it run rich.'98 K1500 Suburban LS 5.7 L 4L60E NV246 ARB
'92 Ford Explorer XLT 4x4 4.0 L A4LD BW13-54 Trac-loc rear
"My toys were the greasy cogs and springs and pistons that lay around all over the place, and these, I can promise you, were far more fun to play with than most of the plastic rubbish children are given nowadays." Danny in Roald Dahl's Danny The Champion of the World
06-15-2009, 08:30 AM #10
- Join Date
- Apr 2009
Originally Posted by AZ_Kid
I hope this is helpful.
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