Low Oil Pressure on cold Start
 

Hi.

I am trying to find some explanation on my problem: When I cold start my 2002 s60 2.0T, eraly in the morning, the "low oil pressure" advise comes on, since the engine takes 5 to 6 seconds to turn off the oil pressure light. There's no thicking noise in the head, so I realise the lubrication is ok that.

I changed oil sump o'rings, even the oil pump and gaskets, and the pick up o'ring.

The problem my mechanic said is that the oil, somehow, when I turn off my car in the night, comes down to the oil sump, and always in the cold start, the car acts as I had changed the oil.

In the oil pump, also, after the cold start, we notice some noise, like the air passing through the pump... but this ends in a few minutes. After the stratup, I do not get any other advise, and oil pressure runs just fine, in low and high RPM.

Can anyone help me with this? Where can I search to stop this "drain back oil" to the oil pan when the car stops for one night? We checked almost everything and the problem persists.

Thanks for the attention.

Why on cold day on first start up in the morning earlier only my oil pressure gauges stay low in a light check?
why on cold day or first start up in the morning earlier only my oil pressure gauges stay low in a light check gages come on? After 2 min the oil pressure go back to normal, it this normal the engine sound good?