I have a 90 Civic si with 165,000KM. I did a tune up about 2 weeks ago and I changed the oil to 10W-30 Mobil 1 SuperSyn. I checked the oil today, and the dipstick was DRY. I think im burning ****** oil. I tried putting in a longer dipstick (pontiac grand am) and I hit the oil pan with it. When I took it out it was covered with oil, and the oil was pretty clean. Any ideas? Oh, sometimes when im driving around and I leave a stop sign or something, black smoke comes out, but only when I rev it up high. People are telling me different things, like if you change to synthetic, it will burn fast, or I need new piston rings or valve stem seals. I can't see why I would need new piston rings, the car is in good shape, with low KM's. Im hoping it's just valve stem seals, but how can I tell?

 

You are probably burning that oil out. You can't switch to synthetic on a high milage engine or it burns.

Also, when did you check the oil - Was the engine cold, hot, running,...?

 

Damn that was alot of info..

Synthetic will burn easier on older cars.
switch back to dyno oil, and check your oil more frequently.

The black smoke on high revs can be too much fuel also. Usually blue smoke is oil, black is fuel, and white smoke that smells sweet is coolant.
Stop revving it up high.

You may be burning oil because of a bad PCV valve, valve stem seals, valve guides, oil rings may be stuck. I can't tell from here.

 

Thanks guys you helped me a lot. I was kinda had a hunch that synthetic oil will burn faster, BUT, I did a oil change 2 weeks ago and when I checked it, the dipstick was DRY! I think i'll change my O2 sensor as well, cuz I'm runnin rich I guess. And by the way, what oil should I use, take it in mind that I live in Vancouver, Canada. I put in some 10W-30 Castrol non-synthetic oil. Which oil brand should I use? Valvoline, Pennzoil, Castrol?

 

BTW, do piston rings usually go bad on these cars?

 

IF it was your rings, then its your oil rings getting stuck...

that all depends on how your car is treated..

try 10-40, dyno oil..
I don't have any brands to recommend other then changing your oil every 3000

 

Castrol GTX 10w30 or lower if it gets very cold there.