I have been tinkering for a few months on my girlfriend's '83 240DL waggon, and so when the time came for me to get a new car I knew I wanted a Volvo. I found an 850 Turbo that I am interested in and I test drove it. Everything appears %100 ok. The only slightly suspect thing is that the check engine or service engine light was on. The owner says that he had it checked out, and that it is just an overly sensitive sensor or something and that a mechanic told him not to worry about it. Knowing the sensors on my girlfriends 240, this sounded very reasonable.

I opened up the hood on the 850 and could instantly tell this was not a 1983 240! I had no point of reference and the thing just looked like a big computer. The engine sounded good and wasn't shaking but that was about all I could tell. So my questions are these; What are common problems in these cars, and where can I look for wear and tear? What is up with the engine light? I don't want a car with a blown head gasket. I have heard to beware of problems with turbo engines, but what are these problems and symptoms?

Here is a link to the listing for the car with all of it's info:
http://losangeles.craigslist.org/car/68421380.html

Please reply soon if you have any info to share. This guy is waiting for me to make up my mind.

Thanks,
Ryan