2005 v50, 97.6K miles. Starting a year or so ago, the CEL started coming on after a cold start~whole car shook.. Dealer mechanic said codes indicated all cylinders were misfiring. Replaced fuel pressure sensor (3 times), spark plugs (2 times). The CEL would stay off for a couple of weeks and then reappear. Tried several dealers....no luck. So I took it to independent Volvo mechanic who found that compression in cylinder 4 was low (came up very slowly to 135...other shot up immediately to 180). He said the problem was not the coils. Mechanic says that he has to open up, and possibly replace engine. But this is going to cost more than the car is worth. So he suggested that I just keep driving it because it is otherwise in great shape.
Now, the CEL has started coming on after a couple of days and not necessarily after a cold start. Did an exhaust gas check in the radiator and no indication of head gasket leaks. Taking off oil filler cap- there is no blow by. Any ideas about what might be going on? I really love my car, but not sure whether it is worth spending the money to fix a 13-yr-old car (I bought it new). I have to have the car inspected, and as long as the CEL keeps coming on, it will fail. Soon I won't be able to drive it anymore.