Following a series of stupid mistakes, I overheated my 1994 850 2.3L turbo. Soon thereafter. although the car seemed to be running ok, a great deal of pressure built up in the coolant system, and I had leaks in the radiator and (new) expansion tank. The coolant pretty well drained out of its own accord. I tested the compression and I have about 35% lower compression on cylinder 4 than on any of the others, which vary by less than 3%.

I figure I have at best a bad head gasket, or a warped head, or at worst a problem in the block. My first thought is to pull the head and take a look. But, from what I've read in my Chilton's manual and on this site, I may never be able to reinstall the head or reassemble it once I pull it apart. I will get a Haynes manual, which some on this site have implied gives better instructions and a possible work around to various Volvo tools required, but I guess I have my doubts that I'll find anything there that will help all that much.

I figure my options are to get a used or rebuilt engine assembly and replace the entire engine or to tow the car to a mechanic to have the head done.

Does anyone here have any practical solutions to the cylinder head reassembly/reinstallation problem, or practical advice or alternative options to those I've suggested?