Hey Guys -

I just bought a 2005 Volvo S40 2.4i and it makes a rattling/knocking/fan-hitting-the-shroud type noise when the vehicle is in drive and idling. As soon as you touch the gas and it moves above idle it stops. Reverse is quiet. Park and Neutral it happens occasionally, but mostly only in drive.

Does anyone have any idea what this noise is or how to make it stop?

Any insight would be greatly appreciated.

Thanks.

 

I know this reply is 4 years late, but we just encountered and repaired the same issue. Ours too sounded like a fan hitting plastic. Look at the plastic air intake parts by the oil dipstick that must be removed each time you change the oil filter. Over time they loosen up and rattle under the idle. I took the apparatus apart and fastened strips of duct tape to act as a barrier so there's no more plastic-on-plastic rattle. Reattached and sounds great!!