I was cruising in second gear last night coming off a turn approaching my friends house, when all of sudden, the oil pressure light came and at the same time there was a high pitched knocking or pinging that I've never heard. It seemed to come from the block.

Specifically, I was going from second to neutral @5500rpm precisely when it happened. Then I turned off the car immediately and let it roll to the curb.

Its a stock GSR block with 180k. Am I loooking at some kind of engine failure?

edit: I let the car cool down and checked the oil. Its full. All fluids were full.