Carbon marks on ground from exhaust -
  • 1 Post By Delta0
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post #1 of 4 Old 06-09-2021, 12:47 PM Thread Starter
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2004 WJ 
Join Date: Sep 2012
Location: Pittsburgh
Posts: 693
Carbon marks on ground from exhaust

Over the last few months, have noticed carbon marks on the ground after starting the Jeep - 4.7L standard output, 140K miles. Carbon seems to be there after startup but could also appear under easy acceleration.
Engine seems to be running normally.
Any suggestions on the most likely causes of this situation?
Am thinking of adding a can of seafoam to the gas, and a quart of Marvel Mystery oil into the oil to help 'clean' out any buildup.
Probably go out on highway a do a number of 0-80 MPH with accelerator floored to help blow out the carbon.
That may cure it temporary but probably wont address the cause, which is what I am after..

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post #2 of 4 Old 06-10-2021, 08:11 PM
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2001 WJ 
Join Date: Oct 2019
Location: Pasco
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I would think you should be able to pull codes to get you started.
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post #3 of 4 Old 06-11-2021, 02:25 AM
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Condensation in your exhaust pipe washing soot out?
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post #4 of 4 Old 06-11-2021, 08:13 PM
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2000 WJ 
Join Date: Jan 2020
Location: Near SLC
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I think delta0 has nailed it. Just needs a good Italian tuneup and some freeway miles

'00LMTD-4.7l,242hd,D30,D44A,3.73's,True-trac front,Spartan rear,4" short arm lift,JK'sW/32's
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