extremely excessive carbon deposits

wagodizzlewagodizzle Council Member and EDM expert
in Engine & Drivetrain
ok, here is whats up...

there is an extreme amount of carbon/black stuff coming out of my exhaust, and it gets spread all over the back of my car it has been doing this for a while but now its really getting on my fricking nerves.. three reasons why:

1. bad for the environment
2. REALLY bad for the environment
3. gets my car dirty in less then 2 minutes of driving

i have tried searching on the web what it is, but i am not really getting an answers.

specs:

-'91 DX wagon
-325,000 miles on engine :lol: :mrgreen: burns a quarter of oil every 400 miles
-has done this briefly before (but not nearly as bad) with my original engine as well which only had 120K miles (burned a tiny bit of oil)
-MPFI swap done by yours truly

i let my car idle for about 2 minutes in the garage when i was tinkering and a large area of concrete got splatter with this watery carbon deposit at the exhaust outlet.

any one know what it could be?

Comments

  • HaydzHaydz Moderator
    Thinking its just oil combined with running rich.

    If waterjacket had been breeched it would probably be steam...
  • wagodizzlewagodizzle Council Member and EDM expert
    how can i "control" the running rich part?
    that make sense though, if i rev past like 5000 rpm black smoke comes out (burning fuel)...
  • stampernstampern Senior Wagonist
    Usually black on the back of your car is oil burning. I've had a few cars do that when they burn oil. Common causes are bad rings or bad valve stem seals.
  • wagodizzlewagodizzle Council Member and EDM expert
    well, the engine has 325K miles on it :lol:
  • bam-bambam-bam Council Member
    That engine is just tiiiiired. All that black stuff on your car? That's what's left of the oil you're burning. It was doing the same in my car. That swap was just a temporary measure to keep you going until you can come up with something else. I wouldn't expend much time/money/effort on the engine unless you're going to rebuild it, or rebuild your original one to put back in.


    or SWAP IT :D
  • wagodizzlewagodizzle Council Member and EDM expert
    ok, thanks Bam =) i was just getting worried that it was something other than the engine (electrical, components, etc..)
    i am definitely going to swap it.. once things actually smooth out in my life and i get to save a little money for myself.

    mmm, DOHC ZC, mmmmm

    other then that, engine runs great :mrgreen:
  • progressprogress Wagonist
    That's happening to me as well. Another reason it sucks? Hands and clothes get dirty if you forget about it while reaching into the hatch area!

    Are rings and/or seals an easy, DIY fix? I am pretty handy and have my dad who's a forklift mechanic and self taught auto guy, as an assistant.

    Funny story... a friend pulls up behind me as we leave our sons' soccer game. After following me for a mile or so, he decides it's not me as he knew my car was red but the one in front of him was 'black'!
  • wagodizzlewagodizzle Council Member and EDM expert
    haha, mine isnt black... its just, uhh, custom "titanium gray" with "black metallic flakes" in the paint :lol:
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