Sooty Exhaust

[Philbar71]

Ok, so I'm pretty sure my engine is running rich. The insides of my exhaust tips are soot covered, like if you touch the insides it pretty much coats your finger in a thin layer of dry soot. It's been like this since I've had it.

Things i have done to try to combat this:

Replace Fuel Pressure Regulator
Cleaned out entire fuel rail and injectors
Replace spark plugs with E3s
Replace air filter
Used some fuel injector cleaner

My MPG is not too horrible. Before I did all of that stuff i saw about 16-18 in the city, after I'm seeing about 19-21. I don't drive extremely hard but I'm not exactly light footed either. I have not seen any blue smoke from my exhaust that would indicate it's burning oil, but when I changed the oil I was about 1 qt low. I replaced it with some quaker state synthetic, just for something different.

So any ideas of what else it could be?

And I have right over 69700 miles on it.

[cherrington17]

usually soot = burnt oil.

[Philbar71]

usually soot = burnt oil.

Hmm, well I was a quart low on oil last change :ninja: what causes that then?

[alero_bmxer]

piston rings

[jayson_waltz]

^x2

[[ion] C2]

your finger always gets dirty when you rub it inside my pipe

.......

I don't burn oil or anything though, that's how it's always been. Maybe no catalytic converter contributes to dirtiness.

[jayson_waltz]

yea could be a cat problem. but he said it was a quart low last change so thats why i'm sayin rings.

although that is weird for that low of miles unless it has been ran hard a lot.

[AndyT3]

Mine is sort of dirty, but its always been that way. Mine runs 100% too.

[[ion] C2]

your gas mileage sucks though, but isn't too farfetched for winter. i only get 20-23 in the winter it seems, but 27-31 in the summer

[AndyT3]

My gas mileage does suck. After I changed the plugs though it got slightly better. Still have to do the fuel filter though. It averages 21.07 mpg over the past 12 fill-ups.

[mbeals]

Synthetic oil doesn't smoke as bad as dino oil. Cats will also keep it from smoking. Also 1 qt over the length of an oil change isn't a lot. You are probably burning just enough to build up in the tail pipe without being noticable.

Run a dry/wet compression test. That will give you more info.

[Philbar71]

^ how might I do a dry/wet compression test?

And the cat seems fine, smells normal. But not too sure. Never known how to test a cat tho?

I dont think it has been driven too hard but the previous owner must have been carrying around the worlds fattest man in the back because the rear struts are completely blown :/

And the previous owner was retarded and got the oil changed at walmart, where they put in some crappy, bulk, conventional oil in ever since they had it.

[jayson_waltz]

if its changed every 2500-3000 conventional is just fine. that should't be a problem.

What is meants by dry/wet comp test is do one dry and do one wet. to do one dry just do it normal. to do it wet, dribble a tad of oil down the spark plug hole before doing the test. The reason of doing both is because then if the comp results are higher with the wet test than the dry test, your rings are shot. if it isn't higher, you are losing comp somewhere else and you dnt need rings. more convenient for 2 strokes than 4 strokes imo.

and cats usually aren't bad until they throw a code of it starts running like crap. it will be 100% obvious when they are clogged, just building up maybe not so much.

[mbeals]

For normal driving conditions and 3k mile change intervals, bulk walmart oil is just fine. I've personally seen engines with 200k+ miles still running strong on crap bulk oil.

Google compression test for the details, but the basic idea behind a wet/dry test is that you test compression on a cylinder, the squirt a little oil in the cylinder and test it again. if you are losing compression in a cylinder, this tells you if it is rings or valve seals leaking.

[Philbar71]

^ Hmm, ok. I'll just have to find some one with a compression tester. I dont think either of my parents have one.