I have a 1996 Volvo 850 which has some kind of serious valve or piston problem. The mechanic said that there is zero compression in cylinder 2 (its a 4-cylinder GTS). He said he could not see anything with the boroscope and that to diagnose it further he would have to take the head off, but he said that with this kind of car it is very difficult to do that and requires special tools. He also said that with older cars, if you fix and tighten up one set of valves, it can blow out others. The car has 260,000 miles.
Is what this mechanic saying true? Am I better just getting a replacement engine or different car, or is he exaggerating the difficulty of the job?