Correct PCV Valve picture please?
 

Hi guys,
65 GMC with the L6 230. I met a guy with a 66 c10 who said my PCV valve was wrong and it was contributing to oil leaks. Does anyone have a picture of the right PCV valve installed on this engine? I want to double check how it looks and fits, and also make sure I order the right part the first time.
Thanks!

Re: Correct PCV Valve picture please?
 

Picture of my 292, if it's on the valve cover and a 60's engine it will look like this.

The most common oil leak on these is the valve cover. It is common to get two Rubber gaskets to aid in sealing. The valve covers are thin and warp easily.

Re: Correct PCV Valve picture please?
 

Thanks TJ, kinda tough to see exactly what it looks like from your pic. When I get home today I will take a close-up picture of my setup and post it, and get feedback from y'all on whether it is incorrect.

The guy I met said it was loose and therefore wasn't drawing enough vacuum on the engine, resulting in higher pressure and more leaks. He is a retired airline mechanic so I trust he knows his stuff, I just don't know exactly what I have or what I need.

Re: Correct PCV Valve picture please?
 

Here is my PCV valve. Aside from being horribly filthy, is it definitely the wrong one / wrong size? There is a rubber grommet that it slips into in the top of the valve cover.

If this is wrong, can anyone confirm the right part number to get?

https://lh3.googleusercontent.com/QD...w=w554-h984-no

Re: Correct PCV Valve picture please?
 

I don't know if your's is right or wrong, but easy and cheap to get replacements

http://www.rockauto.com/en/catalog/c...on)+valve,5052

http://www.rockauto.com/en/catalog/c...+grommet,11785

Re: Correct PCV Valve picture please?
 

1st thing I noticed is that yours isn't pushed down far enough. Looks correct to me, but the lip around the valve should be sitting on the grommet. I will get better pictures of mine for you later today.

Re: Correct PCV Valve picture please?
 

Maybe my grommet is just worn out, or the wrong size? It sits kind of loose in the grommet. I agree the valve looks to be the same as what 53lowdown linked to. But also agree that those are so cheap I might as well replace both the grommet and valve.

Re: Correct PCV Valve picture please?
 

If you haven't, shake the PCV and if you hear something inside rattling, the valve should be good. If you hear nothing, get a new PCV along with the grommet.

As a side, if the PCV is clogged, oil is probably squirting through the valve cover and oil pan gaskets because of the build up of internal pressure. If the PCV isn't sitting in the grommet properly, there could be a pretty major vacuum leak leading to poor engine performance.

Re: Correct PCV Valve picture please?
 

Have you tried Pushing it further down? It looks like it's just Sitting on the grommet. The lip I am referring to is the one towards the top closest to the hose. I'm pretty sure that the valve just isn't in all the way. You can get a new valve and grommet from a local parts store as well for cheap. I took mine to napa and just had them replace.

Re: Correct PCV Valve picture please?
 

And just as important, if not more is...
What do you have for a breather on the other end of the valve cover?

Re: Correct PCV Valve picture please?
 

I have one of those big mushroom looking oil caps if that's what you're referring to. Similar/same as what TJ posted.

Re: Correct PCV Valve picture please?
 

Make sure it's open inside.
Not plugged up with crap.
I've seen them plugged off from oily dirt.

Re: Correct PCV Valve picture please?
 

Here's a link with a chart of how the pcv works and a chart of different kinds plus a test to see if yours is working right, Look in post #5
http://www.hotrodders.com/forum/pcv-...on-434178.html

Re: Correct PCV Valve picture please?
 

So are you guys saying the thing needs to get shoved in a whole additional inch to the lip at the middle of the valve(fattest part), or just that it should sit snug against the grommet?

Re: Correct PCV Valve picture please?
 

Here's mine....1st pic is of how yours seems to sit.

2nd picture is of how it is supposed to sit.

Re: Correct PCV Valve picture please?
 

Wow. Yeah I will go try to shove it down like that. Doesn't seem like it wants to go that far.

Re: Correct PCV Valve picture please?
 

Seems like maybe my grommet has hardened to the point of no return because I can't cram the valve any deeper into the grommet. Will go buy a new one this weekend if they have em at the local NAPA.

Re: Correct PCV Valve picture please?
 

Lubricate the grommet with wd 40. Then twist the pcv in.

Re: Correct PCV Valve picture please?
 

Does anyone know the proper PCV grommet part number to look for? Or at least what the proper inner diameter is supposed to be?
Edit: for my 65 GMC L6 230 engine

Was just up at the local NAPA and they don't have anything that looks like the one I pulled out of there.

I also need to get a new grommet for the side of the valve cover, where the hose that runs to the air filter connects in. I'm not even sure what that's called to search for it. Any help is much appreciated.

Re: Correct PCV Valve picture please?
 

Also know that some PCV valves flow on the intake, some flow on the blow-through.
So you can have the system set up the right way, but if you've put the wrong valve in, you're just creating pressure that's going to blow out your gaskets.

-Brad

Re: Correct PCV Valve picture please?
 

Good to know. Any suggestions for figuring out the right setup? Figured someone else with a 230/235 or other L6 might know the right replacement parts to get me running again.

Re: Correct PCV Valve picture please?
 

Everything I'm finding everywhere seems to be 11/16" inner diameter. The one I pulled out had an ID of 0.49". It had paint on it like it was an original grommet. So I'm stumped.

Re: Correct PCV Valve picture please?
 

Factory shop manual should show a diagram or picture.
I found the info in a Year One Nova catalog: there was the regular "open" system, and the "California closed PCV system."
I ran solid valve covers on my 350 (no breathers), with an oil fill tube with a closed cap and a PCV port on it.
Hose went from the fill tube to the base of the carb, with the PCV flowing that way.
At the back of the intake (an old Edelbrock C3B), I drilled a port (with a shield under it) for a hose to go from it to the base of the air cleaner lid, INBOARD of the air filter element. This essentially gook the place of the screw-in port on the back of factory 283 blocks. (which is a road draft tube on open systems)

So it works like this:
Air is pulled from the base of the carb through the PCV in the oil fill tube.
The air is drawn through the lifter valley, under the intake manifold, out the small hole at the back of the intake, up through the port I installed in the intake, through the hose going to the air cleaner base, through the air filter.

I had the wrong PCV on it initially, and the air cleaner filled with oil because the carb sucked the air the wrong way (through the top of the carb, above the butterflies, rather than at the base of the carb), bringing oil with it up into the air cleaner.

That probably doesn't help you specifically with your inline, but it at least gives you an idea of how a PCV system should flow.

-Brad

Re: Correct PCV Valve picture please?
 

Yep, I found similar info in my shop manual. There were a few diagrams but no measurements. Mine has a closed oil cap, and pulls in air from the air filter which goes into the front driver's side of the valve cover via an inlet tube, and pulls it out the PCV valve in the back.

So that means the vented oil cap I bought from a member here is superfluous (even though it looks cool). I still have the closed cap somewhere I think.

Regarding parts, I need to find both the proper grommet for the top where the PCV valve plugs in, as well as the front driver's side where this tube connects. I can at least find PCV grommets w/ an ID of 11/16" but I can't find any mention of the grommet for this inlet tube.

https://lh3.googleusercontent.com/4I...w=w281-h499-no

Re: Correct PCV Valve picture please?
 

I took my valve cover into Napa and had them match up some universal pcv grommets to mine. Then I got a new pcv valve. Just ask for one under a 1966 chevy c10 292 I6 and it'll be the same, and if they can't figure it out...let me know and I'll talk to the guys here as they know more than just how to type. :chevy: