+1 on this ^^^^^. The 'rattle test' is fun to do but simply replacing the PCV valve is a much better choice. I might go more than 30k, but PCV valves are not that expensive. If the valve gets stuck (either open or closed) it can do serious mischief on your engine.<snip>NOTE: I would replace the PCV reguardless whether it works simply due to the mileage of your Foz. Not sure what the service manual states for that year as far as how often one should change it out, but I replace my 2003 Toyota RAV4’s PCV every 30k. She’s old with 155k original miles.