Sometimes there is a rattling noise at warm idle, its something in between tin can rattle and rubber squeling from the fan belt, if that makes sense... It's not constant it rattles a bit the goes away for a few seconds and then comes back again. If i rev the engine the sound dissapeares. I believe its coming from the top of the engine and towards cylinder #4 this has been running lean because og vacum leak but that is now fixed. If i lay down under car i can hear the sound coming from exhaust pipe. I'm pretty sure it's not any loose exhaust things, and it's certainly coming from the front of car, but you never now. The egine is still hunting at idle, maybe the two are connected. It doesn't hunt bad perhaps 50-100rmp. All spark plugs read fine. The engine is otherwhise wery smooth and quiet(B19A) It has only 105K and is a one owner who has serviced it regulary. Can it be a worn wrist pin or somethin mechanical, like the valves are adjusted wrong? I can bearly hear the valves. The engine is very quiet at idle (800 rpm), apart from the rattling. If it was a wrist pin or something it should be worse when cold right? There is no sound at cold idle. I adjusted timing to 14 deg adv. yeaterday and it seems as this has brouhgt the sound "on" ofter. But i also tighten the fan belt at the same time. I'm tinking it can also be the water pump, but it doesn't come from there. I will do i compression test later today. If it's good and even i wont take the head off, i may do if it's uneven. I really hope there isn't something mechanical wrong with the engine, especially not the bottom end, something that would be guite strange considering the low mileage(for a volvo)?

Any advice appreaciated.