My truck does not seem to ever burn any oil but it has started to ping pretty frequently.
It seemed to start after I dumped a can of Seafoam down the intake????

It pings under load quite a bit now.

I can see a film of oil in the intake area but my mirror got broken so I can not see in the corners.

I did remove the air breather line from the CAI and there is a good bit of vaccum present coming from the valve cover.

I suppose my question is this?

Do you have to disconect the PCV valve to verify the problem or is any vaccum a sure sign?

Thanks

David

 

Using my cheap gauge I have about 2" of vaccum with the PCV line capped off and about 5" of vaccum with the line hooked up.
In either case it must build for a few seconds to show on the gauge.