I have a 2000 s80, noticed water level going down, found a pin hole in overflow. Got a used overflow, now when I drive then stop water gushes out of overflow cap, but does not overheat. I've done a little research on pcv because of oil loss, oil level goes down rather quick but no drips in driveway and no smoke?, and I don't think water pump is leaking. Should I put new pcv parts on or what do I try? Thanks Kevin

 

The PCV should not affect your coolant system.
That is for crankcase pressure and if blocked up usually blows camseals or rms.
oIl can force out thru the oli filler cap onto cam cover also.
A simple glove test over the oil filler opening will show a problem there.
The glove should try to suck into the opening which it should do.
if it inflates then the PCV is due for servicing too.

If the engine coolant is coming back out thru the reservoir cap you may need a new cap or its seal.
Excess pressure may also build up if the thermostat is not operating (opening) correctly pushing coolant back up also, even though the temperature is not sufficiently excessive enough to move the temp gauge up to the red.
First step is to check condition of the reservoir and that the cap is effective, top off the coolant level and watch it over a period of driving to see if the problem persists.

 

Thanks, the glove just laid there until I reved the engine then it tried to suck in a little. went to work and back no water came out today. this car has really been a trouper, hope I can keep it going. thanks again

 

If the glove does not inflate at idle but then shows some suction at higher rev's then the PCV is probably okay but is not really super ok.
Had it inflated then one could assume it was clogged up badly and urgently needs attention.

re; the coolant level sensor in bottom of reservoir. Sometimes they can stick or fail to operate and need to be replaced but all may yet be well now the level is in the correct range.