2001 S80 with 213k. Car started idling very rough a few days ago. runs fine in 2nd gear and beyond. Check engine light is on, sometimes blinking. Red triangle warning light is NOT coming on, just the 'check engine' light. It feels like an ignition coil going bad.

Took the car to a friend with a code scanner...got a 'misfire cylinder 1' code. My pal checked the compression...cylinder 1 was at 8kg. All other cylinders at 14kg. So my friend says it is almost certainly an exhaust valve going bad. he says, trade this car in because it won't last long.

Another friend said that the cylinder could go bad in a day...OR, I might be able to drive it as is for 6 months, hell maybe even a year. He says put seafoam gas and oil treatment in it from time to time, he's seen that stuff work miracles. I don't like the idea of rolling the dice and getting stranded in the middle of nowhere someday, but unfortunately my resources are limited and i'd rather not get tied up in a car payment until after the first of the year if i can help it.

Has anyone just decided to drive an engine with a bad cylinder, and been pleasantly surprised by how long it lasted?
thanks in advance.