I have a 94 B18C1 with ~100,000 miles in my hatch. The motor runs great..doesn't smoke or burn any oil. However, the oil turns black pretty quick. Right now, 300 miles after an oil change, the oil is turning brown but is still semi-transparent. In another 300-400 miles it will be solid black. What's causing this? What do I need to do to fix it?

I'm using Castrol GTX 10W30, BTW.

 

it's doing it's job

 

that's completely normal. There are detergents in the oil that clean up all the soot and carbon deposits in your engine. The oil turns black because of the deposits it has cleaned from your engine. If it didn't turn black, that would mean either, A) your engine is completely clean (never going to happen), or B) There are no detergents in your oil, and the deposits are still clinging onto your engine parts..

live with the black oil.

 

Oh ok. Thanks.


91CivicSi <---Still learns something new everyday.

 

yeah, just sounds like your engine is dirty and the oil is doing its other job (lubricating/cleaning)

 

would several short mileage changes be good to get some of that crap out?

 

you have an intake.

clean the intake.

and whatever the others said...

 

Yea, I was wondering the same thing.

If your refering to the filter, it was cleaned at the last oil change/turbo install. I've got a little bit more than an intake going on under the hood.

 

I am wondering the samething.

 

I think it is blowby. My prelude used to have dark straw colored (still translucent)oil when I'd change it at 3000miles. Now the car has 150k hard miles (track and autoX) and it turns black after 500. Same thing, doesn't burn oil or leak. After a lot of miles the rings don't seal quite as good and you get more soot from the combustion chambers I think. My dad's B16 civic is really clean. It looked like new on the dipstick, but he said it had 5000 miles on it.