Valve lifters produce that sound on first generation Stealth and Mitsubishi 3000GT, you can keep it that way as there is no real mechanical problem besides the almost insignificant noise, or change them for third generation valves (anywhere from $100 to $300 USD).
The easiest way to check this is to pop out the PCV valve. Once it is out, inspect it for dirt or oil, and give it a shake - it should make a rattling sound if things are in working order. It doesn't hurt to change your PCV valve after a period of time just to keep things running well.
What is making the rattle sound? If it is a rattle-snake, the rattle is to warn anything the rattle-snake believes is a danger to the snake, to keep away.
Use plastic silverware!
A rattling sound from underneath a car can be anything. It can be a Loose, worn out, broken, or even a bent part. Sometimes a foreign object can be stuck to the bottom of the vehicle. One thing you have to keep in mind, don't rely on where you think the sound is coming from while your sitting inside the vehicle, Sound resonates from under the vehicle.From my past experience as a mechanic, The most commonrattling noise from under a vehicle at Idle was the 'Heat Shield' from the exhaust.The best thing to do is to inspect and listen from the underside of the vehicle to pinpoint the location of the rattle...
because you did it wrong
new weather stripping.caulkingor new window assembly
One directional valves keep blood in the heart flowing in the right direction. There are three valves: biscupid valve, semilunar valve and tricuspid valve. These open to let the blood flow through then close to prevent the blood flowing back in the wrong direction making the heart less efficient.
COULD BE YOUR VALVE SEALS OR PISTON RINGS DONT SOUND GOOD HOW MUCH MILES
check valve
no, the tension the strings keep on the bridge keep the sound post up: if you let the bridge down, you risk breaking the bridge, the strings, and making the sound post fall down
the best way to get air out of pipes is to make sure all the taps are closed incl your mian valve and to open a section of piping outside. then turn your mian valve on thereby forcing the air out of your pipes