jkelley

I have a strange oil burning situation... I think. I don't keep track of how much my car burns like on a spreadsheet or anything because I know it is VERY low burn rate. But I do know that I have checked the oil before and seen it go from the top X down down to the middle X over some substantial amount of miles and then topped it off (at least 3k miles, probably more like 5k miles). It seems like when I do that, the top end it burns down faster then once it gets to the middle X, the burning stops completely. I tested this recently by letting it get down to the middle X and just left it since I know the car is safe at that level, especially as a street-only car. Now it just stays there. Doesn't budge. I'm probably about 5k miles on this oil (Castrol edge syntec full syn 10w-30 with titanium)

So I guess the question is, is it possible to burn oil when there is more in the engine than when there is about half a quart less?

I have zero issues with the car and just did a compression test (for funsies) and had basically 237 psi across the board, only maybe 1 psi difference between cylinders.

I also did the "click" test on the PCV valve. seems to be working fine.



More info: 2005, 90k miles original, 10k miles on a refreshed head from a burnt valve, driven only on the street, I hit VTEC at least once per commute. Only mod is K&N FIPK. Everything works and runs like a dream. Billman TCT maybe 1k miles ago. Iv'e run at least 3 UOA's on the car and they always come back stellar, not a single thing to even remotely worry about.

Also of note, I used to run penzoil platinum and never burned a LICK of oil. Maybe I should switch back? I switched from it only because of the overall consensus on edge being such a great, inexpensive oil.

jkelley

Oops, double post

bgoetz

I actually noticed a similar trend with my AP1, if I keep topping it off every time it gets just below the high mark, I go through more oil than if I let it get 1/2 way. I theorized that it was likely due to increased shearing and loss through the PCV.

jkelley

So I'll probably just go another 2k miles on this oil and leave it since I know that the motor is safe (considering I don't track it) at the 1/2 mark. We'll see what happens. Mu UOA's say I can take my oil a lot longer so I guess this time I'll listen to them lol.

S2KERRP2

I have MY05 as well and I barely burn any oil either and I use the same oil and I get the EXACT same thing. Never drops below the half way mark lol

On another note how did you burn a valve on a 05??

jkelley

I bought the car with a burned valve. Didn't realize it at the time obviously, but did a compression test a week or so later and very low compression on #3. Car ran great though... believe it or not. Could have been a bad valve adjustment, bad injector, who knows. I had the injectors flow tested and cleaned and #3 WAS a good amount lower than the other 3 so that may have had something to do with it.

windhund116

Perhaps it's the total oil pressure that is effecting loss. Greater the pressure due to amount of oil, the greater the burn-off. Once, the level or volume of oil drops, the pressure drops enough to reduce burning.

Mind you, just a WAG.

zeroptzero

That oil consumption isn't high , not something I would worry about.

Driving style has a lot to do with consumption, and oil brands do vary quite a bit too. Oil viscosity has an effect too, even among 30 weight oils, you can have thinner 30 weights and thicker 30 weights, all within a range.

Go back to the "other" oil brand and see if consumption drops again. Penzoil Platinum has a pretty low NOACK volatility rate, I'm willing to bet it is a fair bit lower than Castrol Edge. That can make a difference.

One other thing, new oil burns off some of it's weight quickly right after installation, as the light parts of the formula vaporize. Then the burn off rate stabilizes with increased use and age of the oil.

I don't think the level of oil makes a difference unless the sump is over-filled. I'd be quite content with that oil consumption but I know it can play tricks on your mind if you let it. lol.