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?