dubcityb20

Change it your oil, give it a new filter and keep out of tec. Check it at 1500 miles. See if theres a difference. By all means, check your oil for grittyness etc before changing. If it doesnt feel gritty or smell really bad, keep going with it. If the consistency of your oil feels and smells fine, but is just black in color I'd just wait to change it. And when you do, try what I said first and see if theres a difference. Chances are its just carbon from being richy-rich and hitting tec.

00siboy

iTrader: (3)

richy-rich? please explain...

dubcityb20

When you are in tec, it dumps more fuel to compensate for extra air being sucked into the cylinders from your extra lift... More fuel means that you are going to be running richer... More fuel= more carbon. that carbon will get trapped in the thin layer of oil that is on your cylinder walls. That oil is then scraped off by your rings and will eventually get mixed in with the rest of your oil. carbon in your oil. Makes it turn black.

00siboy

iTrader: (3)

but since the ecu is compensating for the increased air flow, wouldnt the a/f ratio still be burning efficiently, and not causing it to run rich?

m_shake

Yes, if there was no increase in air supply, just fuel, it would be rich...but the ecu increases fuel supply to the air increase, so you are incorrect.

m_shake

and please stop calling vtec "tec"....it's just weird haha

00siboy

iTrader: (3)

^^give the guy a break, its pretty hard to type that extra letter

brucepick

My car turned fresh oil black in about 200 miles when I bought it. I used GUNK internal engine cleaner (Very thin stuff. Add to crankcase, idle for 5 minutes then drain all oil and put in fresh). I also used Auto-RX, 2 or 3 bottles. After many oil changes (6 or ten, something like that) it stopped going black so fast, now stays reasonable through 3000 miles. BUT it burns oil like crazy, and I'm still wrestling with that. 20-25 oz per 1000 miles. I drive 600 miles /week so I check it every day unless the weather is insanely bad.

ECU generally is programmed to richen up the mixture when you open up the throttle all the way or nearly all the way. I'm told the extra liquid is there for cylinder cooling. Ya wanna go fast, it will cost you in fuel. No big surprise.

Of course whatever fuel is "extra" beyond matching the amount of air, can't combust in the cylinder so it burns in the cat converter. Unless it gets past the rings...

For blackish oil - I was gonna suggest just changing the filter, not the oil. I tried it once on blackish oil and it cleaned it up nicely. Of course you might not want to if you're using $10-15 filters. I use Honda filters, not tooo pricey.

Scott_Tucker

The color of the oil doesn't have anything with how well it's working. The only way to answer if anything is wrong with your engine is to have the oil tested at a lab like Blackstone.

00siboy

iTrader: (3)

update: so I topped off my oil and have been staying out of vtec, and the oil looks better and I am burning little or none of it. seems to me like just normal b16 with 149k of hard driven miles. probably just losing oil through seals/rings during vtec because of higher pressures. I had suspected this from beginning, just wanted to see if anyone could tell me something I was missing. thnx guys!

revolution920

holy **** u guys noe alot lol. i was having this problem too in a b18c motor and i been trying to figure it out now i will try everything u guys said. lol besides the seafoam part lol

N/A

Someones lightbulb just turned on...

Its not brain surgery guys...

kaiba

WHAT EVER YOU DO. DO NOT FLUSH YOUR ENGINE WITH WATER.

00siboy

iTrader: (3)

water? wtf? are you speaking from past experience? way to throw something in way off topic!