Volvo Repair: 01 V70 T5 Low oil Pressure - No oil pres., low oil pressure, v70 t5

Question
James,
Just bought a 01 V70 T5 with 39K. Drove it for a few weeks (1K miles), no problems. Had non-Volvo dealer do Tranny flush and fill(with Volvo Syn fluid), as part of sale, and had Volvo dealer do recall/update on computer program. at first the car drove great minor hesitation on take off, but is intermitently getting worse, do you think it would be an adjustment or copmuter problem? Also just had oil changed ( @ Valvoline Quick Lube)10-30 valvoline full Synthetic) and am now getting a low oil pressure or no oil Pressure warning only at Idle after car has reached temp. Seems to be worse when warmer out side. Had shop double check filter and it checked out ok, no foaming or obstructions. they said it is probably the pick up o-ring. Does this sound right and can you please explain why this  happens to an oring?
Thak you for you time.
Kurt

Answer
It is the oil pickup o-rings.  Can't quite say why it does it but volvo released a bulletin explaining the problem and the procedure to fix it.  Not much I can say about it.  The hesitation is probably a throttle body problem.  There is an extended warranty for that specific component because of numerous complaints, and a service campaign for updated software that should be performed free of charge.  Call the dealer with you VIN and ask if Service campaign 155 has been performed/available for your vehicle.  Then if you have yet to have it done, schedule an appointment. It should help.

James