QuestionI have 202.000 km on board and I use Syhthetic Oil, last time changed about 1000 km now and ... when I sit on light the low oil light comes ON. Then disappears and on the next stop/lights it comes ON again. After an hour it doesn't come any more. The oil level looks normal though... What could be the reason?
AnswerHi Miki,
This is fairly common, and is exacerbated by the use of synthetic oil. This can happen too with all makes/models. If your idle rpm is a little on the low side which means the pressure is going to be low enough to turn on the light after the engine warms the oil, which also lowers the pressure a bit. But there is not easy way to change the rpm unless there is a fault of some sort.
The actual minimim oil pressure is 5 psi so if you wanted to check this out you could have it measured with a gauge at a shop or buy a gauge and substitute it for the oil pressure light sensor located next to the oil filter.
But in my experience I would not be concerned for the moment, but rather the next time you change the oil increase the 'weight' by one step*, which increases the viscosity and thus will raise the pressure at idle so that the light will usually not come on anymore. Another approach would be to buy a new sensor for the light and replace the present one which may be off-value. Either of those approaches don't have any labor charges if you do it yourself.
The only time you really have to be concerned is if the light comes 'on' when you are driving and the rpm is higher than about 1,000 rpm as that could mean there is insufficient oil reaching all the moving parts.
Roland
*If you have been using 5W-20 try instead 10W-30 for example.
