Volvo: volvo 850, volvo 850, cam sensor

Question
Hi ray. My volvo 850 generated a 'check engine' (fuel/ignitiion system) light following an attempt to jump start another vehicle. A couple of hours after this, the engine wouldn't start until 2-3 goes. Then a few days later the engine started and stalled and the fault light appeared. I haven't since had a problem with starting, but the engine seems to really idle noisily.  I checked the fault codes but apart from absent signal on my cam sensor, nothing else comes up. Any clues?
Also, do 850 engines generally have a loud idle/engine noise to them? Many thanks.
Leigh

Answer
Leigh,
First I would read the codes and fix the faults. Check the charging system and make sure that it is working properly.
The engines do not usually sound loud take it to a Volvo shop quickly and have them look at it. There might be a bad belt or pulley something that needs attention right away.