[EDNY]

Many, many years ago when the PCV valve first became standard on engines we used a small round plastic gauge that was pressed against the oil fill opening.  It was a clear plastic gauge with a small ball inside, with engine running, it was used to seal off the oil fill hole in the valve cover or fill tube, if the PCV valve was working properly, there would be vacuum in the crankcase pulling the small valve in the gauge to the green (GO) area.

If the ball didn't move to the green area, that might indicate a faulty PCV valve or excessive piston ring blow by.

Anyone remember using one of them?

Been trying to locate one with no luck so far.

[themoose]

Hey Ed I do remember using those quite often back in the day. I had one in my tool box but it seems to have grown legs. There are a couple for sale on ebay. Here's one link
https://www.ebay.com/itm/Vtg-Autolite-PCV-Tester-Pat-No-3-330-248-GUC/254346402352?hash=item3b383a1a30:g:6X8AAOSwum1daqfS

[EDNY]

Thanks Moose..that's the gauge

I tried all kind of search descriptions but could not locate one.

[sixball]

That is a handy little tool. So simple even I could use it.

[chopper526]

Never even heard of it until now........but you guys are much older

[themoose]

We used to have incandescent drop lights too  

[chopper526]

NO WAY!?!?