I recently bought a 2001 s60 (not a turbo). I noticed while ideling; there is a high pitced whistle that appears to be caused by too much suction in the engine (around the dipstick, and/or oil cap). Another odd symptom that may be related: if you pull the dip stick out or take the oil cap off while the engine is running the engine misses/ runs rough. Does anyone know what could be causing this, and how to fix it?

Thanks!

 

I think you have a clogged vent box. It is building up to much pressure.

 

Is this something that a dealer has to fix or can I take it to a mechanic? Where is the vent box located? Is there a relatively simple fix I can do myself?

Thanks for all your help.

 

It is located on the front of the enine. At the back of the A/C compressor. You will have to remove the intake manifold to replace it. If you have patiance and tools you should be able to do it.