awg

an old fashioned spark plug inspection would be very revealing, even just look at a few easy to get at ones

doublechaz

You didn't have a big change in MPG and hard starts and rough idle a while before this happened? If you had a stuck injector you could have those symptoms and if not handled you could wash one bore and start using oil. Not very likely from what you have said.

You could have an oil control ring fowl up and stop doing it's job. Has it always been granny driven?

You could have a valve seal let go for some reason.

I heard once a long time ago that if you have a ring leak it smokes blue to some degree and if you have an exhaust valve seal leak the hot valve flashes the oil to vapor and it doesn't smoke. I've also heard people say that I have that backwards. But the point is that there are internal oil leaks that smoke and those that don't.

Now that we are talking a half quart use in some 'small' amount of miles it could be any of those.

If you are lucky it was a stuck ring that will start working again, or a valve seal that was acting weird because of the cold and very short trips and it will work better when warmer again.

As 54 said, fill and drive and continue to gather data.

awg

" I dont know Art, but I know what I like"

(and it aint the sight of a sparkplug thats been operating in an oily combustion chamber)

RocketMouse

No change of drop in mpg or anything like that... I watch that like a hawk actually. So I can get on top of an issue while it's small and not out of control.

RocketMouse

As far as how it's driven... well at least the last 4 years under my ownership, I don't drive like my butt is on fire like a lot of people seem to these days. I usually refer to my XJ as the one vehicle I've owned that is very unlikely to result in me getting a speeding ticket. lol

robsjeep

"Excerpt from the Factory Service Manual about checking oil level.

CRANKCASE OIL LEVEL INSPECTION

CAUTION: Do not overfill crankcase with engine oil,
oil foaming and oil pressure loss can result.

Inspect engine oil level approximately every 800 kilometers (500 miles). Unless the engine has exhibited loss of oil pressure, run the engine for about five minutes before checking oil level. Checking engine oil level on a cold engine is not accurate.

To ensure proper lubrication of an engine, the engine oil must be maintained at an acceptable level. The acceptable levels are indicated between the ADD and SAFE marks on the engine oil dipstick.

(1) Position vehicle on level surface.
(2) With engine OFF, allow approximately ten minutes for oil to settle to bottom of crankcase, remove engine oil dipstick.
(3) Wipe dipstick clean.
(4) Install dipstick and verify it is seated in the tube.
(5) Remove dipstick, with handle held above the
tip, take oil level reading.
(6) Add oil only if level is below the ADD mark on dipstick"

The above quote came from another post here. I assume it is accurate. I assume the procedure of running the motor then wait ten minutes is to assure consistent dipstick readings. This may have to do with the filter filling with oil, and lifters being pumped up with oil. So evidently the factory thought these things matter for consistent readings.

Two more things, assure the dipstick tube is correctly mounted with the bracket bolted to the block, as if it is not secured, the tube may move about in height, and thus give false reading and make sure the dipstick is fully inserted too, as the seal perhaps fell off the dipstick, or got cockeyed effecting the insertion depth.

good luck

RocketMouse

yes that makes a lot of sense, and generally how I've always checked my vehicles. I'm just primarily concerned with the apparent change in levels when always prior to this event, the level on the stick has never changed (not one single bit) all the way between oil changes. And I check my vehicles a lot more systematically than most people do.