Too much pressure in the crankcase?

[PiLOTLiTE]

When I the engine is running and I remove the engine oil dipstick from the tube, I hear a noticeable change in sound coming from the motor. A friend suggested that I may have too much pressure building up in the crankcase and to check the PCV valve. Instead of checking it, I replaced it (even though the old one seemed fine) and it still does it. Any suggestions or is this normal?

[ August 11, 2003: Message edited by: PiLOTLiTE ]</p>

[mcjoslyn]

What kind of noticeable change in sound? I would be very surprised if you had any significant pressure build up in the crankcase at an idle. If it were that severe, you would be blowing seals out all over the place. Are you sure you're not hearing a different sound because the dipstick tube is acting as a sound conductor?

[PiLOTLiTE]

The noise almost sounds like air escaping, and it gets quieter with the dipstick out. I was thinking yesterday that the sound of air escaping might sound very similar to air getting sucked in (like when an intake gets louder because of a cold air intake installation which typically removes the air silencer). I have no idea what that would mean though.

[mcjoslyn]

From the way you're describing it, it sounds more like low pressure in the crankcase (which is what the PCV valve will give you). As long as you aren't noticing any other problems, I don't think you need to worry about it. You could stick a vacuum gauge on to make sure you aren't sucking air someplace, but I think you're probably fine.