Excessive soot in tail pipe
 

Hi all,

I have a 2000 Accord EX-L coupe, 4 cylinder 5 speed with 149k miles (bought it in '09 with 95k, and the previous owner had excellent records). My tail pipe seems excessively sooty. I'm not sure if it's normal and I'm just a car hypochondriac, or if it is indicative of a problem.

The car does burn some oil, though the soot in the pipe does not feel oily. It burns about a quart every 1300-1400 miles. Seems like a lot to me, but Honda alleges that it's normal. It does make that nasty diesel sound until the engine is warm. Sometimes it takes a while for the sound to go away. From my searching on this forum and others it would seem that the sound is a bit of piston slap, which is also allegedly normal for these motors (still doesn't sound comforting to me).

I've been changing the oil every 3000-5000 miles with Mobil 1 Tri-Synthetic 5W30, and I Seafoam it about once a year through the brake booster vacuum hose and in the fuel tank. Last time was about 10 months ago. Car does have a new catalytic converter, replaced in June. CEL is not on, and there are no codes.

Do I need to worry about my sooty pipe, my oil consumption, or that nasty diesel sound? Or should I just chill out and enjoy my smooth ride?

Check your PCV system to be sure it's not blocked and causing oil-rich vapor to be pulled into the air intake. A dirty/oily duct downstream of PCV air intake point would be an indicator of PCV fault.

Lot's of cars have soot on tail pipe. I would not read anything into this.

Make sure oil is not leaking somewhere.

good luck

Thank you for the response, TexasHonda. The car does not leak oil onto the ground. I'm pretty particular about inspecting the underside whenever I change the oil, and it is bone dry underneath. There is a tad bit of oil that comes out of the valve cover gasket, but not enough to explain the oil consumption. I will replace the gasket in the next month or two anyways when I get around to inspecting/adjusting the valves.

I replaced the PCV valve in December 2009, but it would certainly make sense that a clogged PCV system could cause my car's increased oil consumption. I'll take a look into it this weekend.

Should the nasty diesel like sound cause me any concern, or should I just get used to it?

Thanks again.

Rattling while cold is usually just a slightly loose valves. If it stops as car warms, I wouldn't worry. Valve adjustment should eliminate this noise.

good luck

That's b/c factory tunes are rich. It's a safety issue so that gas coats the cyl walls reduces ware in each cyl but not all of it burns. That's why you see soot. Also if you have a cat back exhaust you will really notice it as a exhaust with no tune will run much richer a/f ratio. That’s why you see nasty black spot on hondas bumpers when ppl have aftermarket exhaust

my '93 uses 1/2 qt @ 2000 miles and I change it at 3000. 220,000.
so your consumption seems a lot to me, too. So what?

I use ordinary 5W-30 except in summer when it's 10W-30.
Chevron, any other is fine, I imagine.
Less expensive oil, why don't you try it - might make you feel better.

Doesn't sound like your car is broken, so I wouldn't fix it. enjoy.
I don't know soot.

Thanks for the responses, gentlemen. I performed a valve adjustment today. All of the exhaust valves were tight, and most of the intake valves were a bit loose. Not sure if that's normal after 30,000 miles, but they are all set correctly now.

The engine does feel a little smoother, but that diesel noise is still there. Seems to be coming from the bottom end, but I didn't feel around with a stethoscope. It basically sticks around until the engine is all the way up to operating temperature. I'm going to post a new thread asking about it.

Thanks again for the help!