hello, I got an issue with the indicator of oil, when I turn the key and with until car conduct some system check, and then I start engine, just a second after, the indicator of oil light and then turn off, after that, everything seems ok, if I turn off and then start nearly immediately, it does not light, but if I wait a bit longer, say a few minutes, and then start, it does not light, what could be the reason?
additionally, when I drive for 10~20 min, and then I run the engine at say 2500rpm or so and simply release the gas pedal, the engine goes to 800rpm, and at that moment sometimes the oil indicator light again....
thanks

 

this is what happens when I start,

 

the engine has to r un for the oil pump to create pressure. it will take a half second to do this.
if its t urning on at 800rpm...you may have a problem. first step is to check the oil level to confirm its no low. if it is low....check for leaks. if no leaks do a oil consumption study. if the study confirms its b urning to much oil....you need an engine or you will need to start toping it up between oil changes.

 

Thank you very much for the replay,
1. according to your answer, the start as shown in the video is ok, did I get it correct?
2. regarding the later part, let me bring more clarification, The oil level is ok, I do check it periodically, also I have never noticed any droplets in my parking area. so I am quite sure there is not any leakage.
3. I have never noticed the indicator turn on when the engine is running on 800rpm,
4. the indicator turn on in the following situation: a) car moves >50km/h, engine 2500~2800 rpm, b) release gas pedal, car keep moving the same speed under inertia, no break, the engine slows down to 800~1000rpm --> indicator turns ON like 1~2 sec ON, 3~5 sec OFF, it may on/off again, or not,
5. The point #4 happen previously a few times, but sins it got off and very rarely (once in several months or so), I just checked the oil level, and I did not pay much attention, but today on/off repeated several time even when I restart the engine and kept at 800 rpm. and one moment it kept ON for a while ~2 min until I stop the car, I leave the car for 30 min and then start the engine, everything was good, drove another ~20 min, it lit again...
p.s. I stay in Korea but I am not good at Korean language to explain this situation to the engine technicians, and the engineers are not good at English, so that is why I am trying to collect more information and delaying my visit to car service center.