Volvo Repair: 98 V 70 engine noise, sewing machine, 20w50

Question
in the morning, when I warmup the car, sometimes the engine sounds like a sewing machine, but after I drive the car for a while, the noise dissapeared. I also notice the oil press lamp on this car is taking a little bit longer to turn off after the engine start (with a lot of noise until the light turn off) if I compare with my S 70

please help....do you now how much gonna cost me for the replacement part?

Answer
Dendy, the Lifters are making noise.  How often are you changing the oil and what kind of oil filter are you using?  Try 20w50 and a Volvo Oil Filter.  If it doesnt go away, then you may have to do whats called an oil pump reseal and that can cost about 500-600 bucks.  Roger