I have a 2003 S-60, Non-turbo,2.4L engine. It has started to make a whistling noise when it runs. There is a strong vacuum in the crankcase. When running you have to pry the oil filler cap off. The noise stops then. Just found out that I can make it stop by lifting the dipstick as well. Any help in this would be greatly appreciated.

 

How long since the engine air filter was changed? Is the filter installed properly?

 

Sounds like your PCV (positive crankcase ventilation) system is clogged.

 

Thank you both for your answers. Yes the air filter is in properly. And has been changed. I fear it is the pcv system. The noise seems to come from that location. I just cant get it off without takeing off the intake manifold. I was hoping for a quick and easy solution. Again thank you both. Randy.