Ford: Frog in my ZX2

I have a 99 ZX2 that when running at idle soulds like I have a pool of frogs
under the hood. Every now and then a squeel like a belt squeal would sound
and then go away. I replaced the belt but the noises still exist. For some
reason I was frustrated and trying to find this mystery noise and I removed
the oil filler cap and lots of air pressure exited and the noise went away.
As soon as I put the filler cap back on the noise returned. I thought I was
imagining it so I repeated the procedure with the same results. Now I am
wondering if anyone has experienced this and could maybe point me in the
direction of what's needed to repair or what could be wrong. I am thinking
there is some sort of valve regulator gone bad, like an EGR type valve but
not sure.

Any help to this backyard mechanic is appreciated.

Thanks

I would replace the PCV (Positive Crankcase Ventilation) valve and be sure
the hose coming from it is not plugged. The valves are a maintenance item,
they have them next to oil filters in parts places. They are designed to
draw air thru the crankcase to suck any vapors into the engine where they
can be burned. At one time, the vent to let air in was in the oil filler
cap. It is usually a fitting connected from the valve cover to the air
intake somewhere these days.

Good Luck

Paul in Dayton


"sf" <junk@junk> wrote in message news:supernews.com... 
frogs 
removed 
away. 
was