On both our cars, the oil light stays lit for a couple of seconds for the first start of the day. Any starts after that the light goes out immediately. It has always been this way and I have always used Mann filters and Mobil1 in both cars.

DEWFPO
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1998 S90 068,300 and 1995 964 152,300

I am interested in your question too, my original engine the oil light would go out almost while the engine was still being cranked for start up. My second engine which is new, the oil light behaves just as you describe. Someone should have some advice, I would love to hear others thoughts on this.

I am thinking that the oil leaks back down the sump pipe, so after a while the oil has to be sucked all the way back to the oil pump to pressurize. I had the oil pressure tested when I first did the swap and the pressures are to the book, normal.

DanR 94 964 256,000 miles (22,000 on the new engine)
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DanR