Edit: I don't know a whole lot about all the fine details involved with PCV systems, so it's just a guess on my part that the plunger weight has anything to do with it. For all I know, it could be any other aspect, or maybe my oil loss issue isn't PCV related at all.
------------------------
I was doing some maintenance on my van yesterday and decided while I was in the back of the engine, to replace the grommet and PCV valve. I had replaced the PCV valve a few months ago with an aftermarket one from the auto parts store, as it was quick and cheap. This time, I ordered an OEM valve.
When I pulled the aftermarket one out, I noticed it has a WAY heavier plunger inside than the OEM one. Like in the order of maybe 2-3 times as heavy. The OEM one rattles when shaken but can't feel the plunger much, where as the aftermarket one feels like a shake weight and hits much harder. Since the PCV valve points straight down, that weight is holding it closed against higher amounts of pressure. How much? I don't know.
Is this a sensitive aspect of PCV valves? Looking at the internals of the aftermarket valve itself, it doesn't appear much of anything has been going through it. The bottom below the plunger on the crankcase end had a little bit of residue, but the exit going to the air intake didn't appear to have anything.
I purchased this vehicle last summer used for pretty cheap. It didn't leak much oil, except for maybe a drop or two once a week, if that. When I did the first oil change, I replaced the PCV valve with the aftermarket one. I started getting a lot more oil dripping on the ground and weeping from the valve covers shortly after this and attributed it to using full synthetic oil on an old engine. It was PUP FS oil which I believe is actually pretty thin for the viscosity grade of 5w-30.
Do any of you with experience with this matter think having a much heavier PCV plunger mounted vertically would create enough extra crankcase pressure to cause old seals to leak more than they would otherwise? Yes, I know the standard "fix your dang seals dummy" response, but that's expensive on these vans, especially when not needing to do other work while it is all taken apart. It can come at a later date.
Or is the weight of the plunger not relevant and it could just be other aspects that may have caused issues?
------------------------
I was doing some maintenance on my van yesterday and decided while I was in the back of the engine, to replace the grommet and PCV valve. I had replaced the PCV valve a few months ago with an aftermarket one from the auto parts store, as it was quick and cheap. This time, I ordered an OEM valve.
When I pulled the aftermarket one out, I noticed it has a WAY heavier plunger inside than the OEM one. Like in the order of maybe 2-3 times as heavy. The OEM one rattles when shaken but can't feel the plunger much, where as the aftermarket one feels like a shake weight and hits much harder. Since the PCV valve points straight down, that weight is holding it closed against higher amounts of pressure. How much? I don't know.
Is this a sensitive aspect of PCV valves? Looking at the internals of the aftermarket valve itself, it doesn't appear much of anything has been going through it. The bottom below the plunger on the crankcase end had a little bit of residue, but the exit going to the air intake didn't appear to have anything.
I purchased this vehicle last summer used for pretty cheap. It didn't leak much oil, except for maybe a drop or two once a week, if that. When I did the first oil change, I replaced the PCV valve with the aftermarket one. I started getting a lot more oil dripping on the ground and weeping from the valve covers shortly after this and attributed it to using full synthetic oil on an old engine. It was PUP FS oil which I believe is actually pretty thin for the viscosity grade of 5w-30.
Do any of you with experience with this matter think having a much heavier PCV plunger mounted vertically would create enough extra crankcase pressure to cause old seals to leak more than they would otherwise? Yes, I know the standard "fix your dang seals dummy" response, but that's expensive on these vans, especially when not needing to do other work while it is all taken apart. It can come at a later date.
Or is the weight of the plunger not relevant and it could just be other aspects that may have caused issues?
Last edited: