Low Oil Pressure on idle or on low speed

The car's only seven years old, but engine problems can happen even before that. A lot of Subaru engines are problematic, and that seems to be one of their most prevalent design features. Defective oil pumps seem to be a regular occurrence, but bearing wear is also. Have a Subaru mechanic review the engine.

First make sure you have to correct oil type and weight. If that checks good then install an analog oil gauge so you can read actual oil pressure, if the oil pressure drops below specs then chances are high that you have excessive bearing clearances inside the engine. When oil pumps fail you loose all oil pressure, some pumps will build it back up after a shut down for a few minutes but will dump it again after a few miles.

A dealer had checked the oil’s pressure telling me that it drops then returns to normal, so he diagnosed that there’s a blockage somewhere in the oil circulation. In case it’s a bearing clearance, shouldn’t appear as a noise in the engine ?

As the excess clearances will be spread through the entire engine you most likely won’t hear any noise

In case it's a bearing clearance, can I use a thicker oil type and drive it safely for one or two months before proceeding to change the bearing at the end of this winter season? if this can be done, what type of oil do you suggest? Should I proceed to progressively raise the thickness of the oil by driving few hundreds of miles using each type.?