Oil level weirdness

I have an ongoing oil consumption problem in my 99 Accord (4 cyl). The
car has 88k miles.

Yesterday I checked oil after the car was parked for about an hour (on
a very hot day) and the level was below the lower mark.
This morning I checked it again (the car was parked overnight, so the
engine was completely cold) and the level was almost at the full mark,
about 90% full. How is this possible???


There are no drip or leak marks under the engine or in the engine bay,
last oil change dealer could not locate any leaks (oil pan seals, etc),
so they asked me to start recording oil levels when I fill up gas.

Any explanations for such fluctuation?

 

This unfortunately is a symptom of a rupture in the engine
block/head cooling system such that it's getting into the
oil system. For example, a head gasket leak.

Check
-- the appearance of the coolant in the radiator, via the
radiator cap, in a cold engine. Same for the coolant
reservoir. If oil is present, it's looking like a head
gasket or similar leak.
-- the appearance of coolant in the oil system. Look into
the filler cap hole and check the dipstick. Look for foreign
residue on the filler cap (white?)
-- Does the car's exhaust smell like anti-freeze at all?
-- Look for foreign residue (white?) on the spark plugs.
-- Is the car overheating at all.

I would not drive the car further until this is resolved. Or
certainly do not let it overheat. This will worsen the
problem and make it more expensive to fix.

 

I am aware of the possiblity that coolant and oil could be mixing if
there is a crack in the engine block. All those checks are negative,
engine temperature is always good. I plan to check with Honda
dealership tomorrow.

 

I have occasionally seen weird behavior like this on my GS-R. It
isn't losing coolant, just takes a long time to get an accurate read
on the dip stick.

Verify you aren't losing coolant. If not, just make a point of
checking the oil only after the car has been sitting for a long time.
I assume the car is always on level ground when you check it.

 

You have already checked for the important problems, oil in the
coolant and coolant in the oil.

Please do not take offense at the following suggestion. I know you are
smart and probably would not make such a mistake. But you never know.
It could be something as simple as not pushing the dip stick all the
way in. I know this is possible because I have done it myself. The
rubber seal around the top of the dip stick is pretty sturdy, so it is
possible to think it has seated when it hasn't.


Elliot Richmond
Itinerant astronomy teacher

 

theoretically. but three things:

1. hondas don't leak much into the oil from gasket failure - the oil and
water passages are well distanced. cracked block is more likely to
cause this kind of leakage in a honda, and that's very rare.
2. if /that/ much coolant was in the oil, over a quart [20%-30% water
content!!!], there would be mayonnaise everywhere, including the
dipstick, not to mention under the filler cap. advice to check the
coolant level [when cold] might be handy in this situation.
3. clogged oil filters and general sludge buildup can affect drainback
times.

i vote for the simple stuff first like the op making sure the oil is
dipped on level ground. sounds trivial, but i'm not joking - had a
similar issue with a buddy of mine just recently. ended up having to
drain two quarts from his overfilled toyota.

 

I know that the level ground is a must when checking oil. The spot
where I check yesterday is not perfecly level, but I would say almost
level. Hard to describe in words, but lets say the car does not roll in
neutral. I assume this would not make much difference.

 

fair enough, just cover your bases!

personally, my civic never gives consistent readings anywhere near warm,
so i only dip cold in the mornings. reading your subsequent posts, it
seems like you've done the right things. i'm guessing this is not a new
car to you and that is a recent phenomenon, maybe since a recent oil
change? if so, consider whether the right grade oil was used.

bottom line, if the car's not got leaks, either oil or coolant, and
consistently dips at the right level when cold, i'd not worry about it.
dealer coolant pressure testing will give you peace of mind, but as
stated before, you'd /definitely/ notice the effects of a quart of
coolant in the oil!

 

Here's another simple problem that's often overlooked. Sometimes the rubber
bushing that seals the dipstick around the top of the dipstick tube comes
loose and will slide up and down. This can account for seemingly random
changes in the oil level.

Eric

 

This is perfectly normal.

There is a right way and a wrong way to check your oil. Consistency is the
key. The very best thing to do is to check it after having sat overnight,
with the car parked in exactly the same spot every time you check. Follow
the *identical same procedure* *every* time you check the oil.

When you run the car, your oil gets circulated around the engine. Depending
on just how hot the OIL gets, (NOT the coolant temperature gauge), the oil
will drain back into the pan faster or slower. The absolute worst time to
check your oil is after a run, even if you let the car sit for a couple of
hours.

 

Perhaps the oil filter anti-drainback valve is leaking down overnight
and thus increasing the oil level in the pan by AM>

I would try a new high quality oil filter to see if the symptom changes.
It might not be the problem, but is worth checking because it is quick
and cheap to do so.

John

 

That is *not* necessary, so long as you have some kind of reference point.

If you check the level the morning after an oil change, then use that as
your reference point, that will do.

 

Take note of any new gopher holes.

 

They call that "FRAMitis"