new problems on 94 used 960 with 164k miles

[RecntVlvoprchs]

About 2 weeks ago, my check engine light came on steady and stayed. Had it checked by mechanic. He said the code indicated an intermittent problem with the crank, and wasn't a big enough issue to deal with. Within the next week, it started giving me some trouble. I had driven for about 12 miles one morning, and stopped for breakfast. When I was finished, about an hour and a half later (I read while I eat), I came out, started the car, backed out of my parking space, pulled into traffic, and the car died. I allowed it to coast into a parking lot, came to a stop, put it in park, and started it. Idled for about 3-4 minutes, slipped it into gear, applied the accelerator, went about 30 yards and it died. This repeated about 3 times over course of next 20-25 minutes. I called a cab and a tow truck and had it hauled to my mechanic. He kept the car for about a week, then called and said all he could find was a loose ground wire which he tightened. When I got the car back, I noticed what appeared to be a little oil in the floorboard carpet...but I didn't think anything about it. I drove the car sparingly for the next few days. Just a couple blocks in any direction separated by long periods of being idle. I began needing to put coolant in the reservoir about every third time I started it, and, the oil level began going down with no evidence of leaking. And, now, it looks like the automatic air mover, which I have set to vent and entering compartment at my feet, is blowing in some oil...my floorboard is covered by what seems to be airborne oil trace. Finally, I drove to my doctor's office today. On the way there, 18 miles from home, just before I arrived, the car died on me. I pulled over, started it up, it ran fine, I pulled into traffic and drove to the doctor's office with no more incidents. On the way home, about 10 miles along, on the highway, I began to lose power, and the engine started running roughly. I pulled over to the shoulder, killed the engine, waited about five minutes, started the car, it was running smoothly, pulled back out into traffic, and went on down the highway. I got to my exit, pulled off, drove about 2 miles of city street driving when it began to run roughly again. Same thing. Pulled over, off, waited, started and ran well, drove on. About a mile further, had to do it again. And one more time before I got home. Any ideas?