I have a 93 960 sw with 175000+ miles on it (she's my baby and all I got, but I’m not much of a car person). I have noticed that it would shake/vibrate a lot on cold mornings, which became increasingly warmer mornings (30-40-50-60). The shaking w/ go away after the car got up to speed
And the other day as I was leaving work, it was shaking when i started it up and then it didn't stop, it was vibrating so much when i was idling and continuing to do so as I started to accelerate, and it didn't go away.

Since I am a college student on a very tight budget, I decided to take my car in to the Volvo dealer for a diagnostics test, and let them use their computers and then I’ll find a non-dealer mechanic.
After 30 min of them checking everything, all that they could say was that it was a problem w/ the ignition, sensor problems, or timing belt, there were no codes coming from the engine, and they would need another $200 to figure out exactly what it was, so I took my keys and left.

So I'm going to start today and replace the spark plugs (since I can do that I hope), but if that fix the problem, I am wanting to know what would be the cheapest next step.

Also any advise as to what might be causing the problem is very welcome, please feel free to post here or write to me @ thickredhair@hotmail.com

And anyone in the northern NJ area that knows or is a good mechanic (that won't rip me off) please let me know. (I'm new to the area)