Hi:
Yes a compression test will determine a loss of compression. However, if you are not getting coolant into the oil, chances are it's just a head gasket. Could it be a cracked block, it is possible, but unlikely unless you didn't have enough antifreeze in the engine and it froze. It could also be a cracked head or warped head, but has the car ever seriously overheated? If not, my guess is it has a bad head gasket. Please understand I can't guarantee that, but that is the most common problem under these conditions. Have the oil changes been done on a regular basis? If so, the bearings and other internal components should be fine. 93K really isn't that many miles today.
The choice is up to you, but if you have a mechanic that you trust, have him recheck the compression and if the guy was correct, have him attempt to replace the head gaskets. That is my feeling. It would be much cheaper than an engine, (around 200 in parts plus labor).
NOTE: This drives me crazy not being there to be certain before giving this type of advice. I am trying my best to save you money and not allow you to get taken advantage of. But not being there has its limitations. Regardless, that is my gut feeling. If you told me the engine was knocking, smoking, rapping, and burned a quart of oil every 100 miles, my response would be different.
Let me know what you think or decide. Also, if you have other questions, let me know.
Joe
Monday, March 2nd, 2009 AT 6:45 PM