Black sut on tip of exhaust and rear bumper?

We may earn a small commission from affiliate links and paid advertisements. Terms

93civicracer

Oh, I do a little here and there.
What could be causing this black stuff to get all over my exhaust tip and rear bumper?

I HAVE been having electrical problems with the battery dying constantly, could this be causing bad ignition and a rich condition?

I've already got a new alternator and battery on the way, and I'm going to check the electrical system for shorts tomorrow but if anyone knows something else that could be causing this let me know. Thanks.
 

haao13

Member
i dont thinks its an electrical problem. its probably just carbon but it could be that its burning oil. my old accord and d15 did and my bumper was always covered
 

93civicracer

Oh, I do a little here and there.
Yeah, I'm getting the battery and alternator because they're done anyway, and I really think there's a short in the wiring.

So you don't think that a pretty much dead battery with no alternator could make it run rich and spit out that sut because of a weak spark?

I think it could also have something to do with the way I screwed with the exhaust, I have a buddy club racing spec 2 full exhaust connected to a test pipe so no cat (yea I know frickin L-O-U-D, but not too bad with silencer :)), plus I'm using the po8 ecu with my swap so I snipped 3 of the 4 o2 sensor wires since I don't need them.

And I really doubt I'm burning oil, I changed the head gasket like 5 months ago and fixed my overheating problem. I'll probably get a compression/leakdown test done soon.
 
Last edited:

hondasaurus

Member
nice car. are you sure the black on the bumper is soot? and not discoloration/burn from heat from the muffler being too close?
 

autox 89 dx

Member
And I really doubt I'm burning oil, I changed the head gasket like 5 months ago and fixed my overheating problem. I'll probably get a compression/leakdown test done soon.[/quote]



Just becaue you changed the head gasket doesn't mean you can't burn oil. It could be leaking from the valve seats or guides.
 

Justin66

The Hondaswap Canadian
^ lol nice.

Has your car had a tune up lately, maybe even a fuel filter change? All those should help clean up your fuel and ignition. Timing also.
 

93civicracer

Oh, I do a little here and there.
do you put alot of tire shine on your car lol

Nah it recently rained before I took that picture the driveway was still wet :D. When I get some GSR 15's and some tires then I will.

It's basically a d15b vtec in the exact shape it was in when I got it from hmotorsonline. All I've done since then is change the head gasket and set the timing right.

The sut is black, not brown and I know it's not heat because it's like a fine powder it just wipes right off. It looks hella shitty if I drive for about a week like that.

My guess would be carbon since it's so fine'a powder. Could have something to do with de-catting and running the p08 ecu with less emissions or something?

Either way I'm going to have a compression test done soon.
 

haao13

Member
scratch the no cat idea. i have a s2 testpipe and i dont have any black on my bumper. i say its burning oil
 

99sidude

Moderator
Moderator
VIP
My vote is that it's running rich. I have a boosted setup, and it's tuned to run rich at wot and during warm up. If i run it hard at all when its warming up it will spew out a nice soot cloud of carbon. The tail pipe has a nice back sooty film on the inside, but nothing gets on the bumper. The car does not burn any oil at all.
 

K2e2vin

Senior Member
Definitely could be running rich or oil.

About burning oil; a bad head gasket is not the only way to burn oil. You PCV could be bad(matter of fact, the PCV and head breather tube allows a lot of oil-vapor-filled air to be ingested), bad rings, leaking valve seals, etc.
 

93civicracer

Oh, I do a little here and there.
I really doubt it's burning oil. I check the oil on a regular basis and it's always been fine, just gradually gets darker like normal. Besides, it's a very very fine powder like carbon. One time it spit out a couple chunks. Still gets hella good gas mileage :thumbsup:

Either way, I'm going to have a compression test done when I get new tires so I can get this car back on the road.
 

serrilion

In my own little world!
Um here is my thoughts mite sound stupid. But my Tip used to be to close to my rear bumper and use to make the bumper hot and melt the crap + the dirt in it, made it soot, black soot... was teriable... just an Idea for u!
 

jdmrex08

New Member
are you sure your exhaust is shooting black chunks? if so i might look into some new piping if i were you or maybe even a new head lol but the bumper being black is probably because of your muffler being close to the bumper, happened on my friends coupe
 

93civicracer

Oh, I do a little here and there.
The bumper looked black because of the shit all over it, it just wipes right off.

Nothing wrong with my piping, except maybe the test pipe not being the same diameter as the buddy club exhaust I have on there and I had this problem even with completely stock exhaust with fart cannon that was on the car when I bought it.

The bumper's not burning.
 
Top