Oil Pressure Problem

[ResonateEcho]

Over the past few days I've noticed that when my car reaches full operating temperature (the middle mark), and running at idle, my oil pressure guage runs in between the middle and red and occassionally will get very close to the red mark, which pops up the orange check engine light.

When I am driving, the oil pressure will rise above the middle mark and remain there until I stop again, then it slowly drops down again.

I have checked the oil level which is at the middle mark of normal range, and the oil/filter is less than 2 months / 2,000 miles.

Any ideas?

[Jerriko]

What grade oil are you using?

[ResonateEcho]

I am using Valvoline 10-40 Durablend. The techniican at the shop recommended it for my milage (156,000).

[Jerriko]

I think that the 10-40 is a little thick for a motor with that much mileage. Does it have the original oil pump?

[ResonateEcho]

Yes, it is the orginal oil pump. What brand / type / thickness would you recommend that I run in this motor? Could you suggest any good additives or..?

Thanks.