Buzz I have a 2003 Volvo S60 and have had it since it was new. It has 94,000 miles now and I have recently notice a reoccuring buzzing noise under the hood after I turn off the engine. It sounds like it is coming from the drivers side, however, I have not discovered what it is or what to do about it. Any recommendations or suggestions?

Buzzing can be an issue with the door lock or central locking mechanism. You could try hunting for where the sound is more accurately. This will sound a bit silly but try this. Sound can travel through solid surfaces so can sound like they are coming from somewhere else. Put your ear against the side of the door panel nearest the handle and lock the car. Your listening to see where the noise is loudest. Listen at the hinge end as well to check if it's actually coming from inside the engine bay rather than inside the door.

sounds like a fuel pump, and those buzz, its just what they do. if its a new or abnormal sound then it might be on its last leg.

Well, most belt companies and aftermarket folks recommend 60,000 to 80,000 miles on a timing belt. You have an interference engine which means if the belt breaks while the engine is running it could damage the valves and pistons. So I would recommend doing it soon.

Open the oil filler lid and see if the noise goes away - or lift the oil dip stick. It could be a gummed up PCV system that causes pressure in the crank case that "whistles" when the engine is running.

By opening the lid or dip stick, you're letting the pressure out and the whistling should stop.

If this is the issue, FCP Euro has a PCV replacement kit for about $350.

how are the plug wires, boosted engine's suffer from voltage leaks in even fairly new plug wires, the added cylinder pressure makes the spark plug require allot more voltage before it can fire compared to normally aspirated engine.

usual cause is the anti roll bar drop link that is worn easy to replace

can you record it and post it on here??like a picture ,i think its possible as it could be anything from a wheel bearing to a air leak on windscreen

If it's buzzing when the car is moving. it could be the wheel bearing making the buzzing sound. it needs to be replaced. you can probably hear it as being inside the hood.

Do you have headlight wipers? If so, wiggle the wiper arm and see if the buzzing stops.

Had a similar problem recently where I would press the accelerator almost to the floor before I got a response and when I ran the A/C it was worse. Also my car kept stalling out when at idle. Volvo dealerships are extremely expensive. I took mine to a Bosch service center (more of a mom & pop shop) and the price was more reasonable. The drivability (sp?) problem was the rear oxygen sensor for me. I also had a fuel pressure sensor and MAP (labeled as pressure sensor from Volvo) sensor replaced. The parts are expensive, but it fixed my issue. There is a front and rear oxygen sensor so it could be either. The parts are $219 each. The fuel pressure and MAP sensor are cheaper, but only by about $40. They are not hard to replace though. Once I had the rear oxygen sensor replaced the car was back to normal. I have a 2003 S60 with 97K miles.