Jackhammer noise during acceleration
 

Hi all. I bought a2003 Volvo s40 about 10 months ago with about 90K miles. I’veran into a bit of an issue – during very slow acceleration (i.e., pulling outof a parking space) there is a loudjackhammer-type noise coming from the front of the car. It seems like it is coming from the passengerside. The noise is only there duringslow acceleration and once I get up to 10 mph or so it goes away. The car seems to be running fine, no issueswhen driving. This issue was sporadiclast week, but seems to do it every time I start the car now. It also seems to decrease after the car hasbeen running. Any ideas?

Check the inner and outer CV joint boots, see if they have lost grease or are torn. There could be a bad joint.

3 areas that I've had a metal-on-metal hammering sound from the passenger side. During acceleration it was the main motor mount where the rubber had separated and slowly worn away until the metal bits started touching. You could not tell it was damaged until you removed it. Luckily it only takes a few minutes to remove it and inspect.

Another was the strut mount. This one made a clunking noise over bumps that sounded like it was coming from behind the glove box. You can tell your strut mounts need replacing by looking at the threaded center shaft sticking through the strut tower under the hood. The shaft should be centered in the hole.

3rd was the anti-sway bar bushing. This was a clunking over bumps that sounded like it was coming from under your feet on the passenger side. To see it you have to jack the car up and remove the passenger side wheel. Then with a good light follow the anti-sway bar as it goes up under the body. At this point the bar should be held down close to the front suspension by the bushing. If the bushing has failed the bar will be up close to the body away from the bushing.