Reed valves in the valve cover at the CCV hose connection holes???'s

I am looking for information on the reed valves that are attached to the inner (inside top) of the valve cover holes. These holes attach on the outside of the valve cover holes to the 2 CCV lines on 4.0's valve cover.

If you know anything useful about these reed valves, pictures please, how they should look, how they should not look, how they should be installed, how they should not be installed, where to get replacement parts, part numbers, and even upgrades to replace them, please post what you have in this thread.

Did these reed valves in the valve covers ever change over the years????? If so what was the change, was it good or bad.

This topic, or part is related, in my opinion to oil loss problems, including (sometimes, but not always) oil getting into the air filter.

Thanks!

Reed valve? Do you mean the PCV? Valve covers themselves have baffles, but I never noticed a reed valve. Maybe I'm missing something?

Do you have a picture of what you're working on?

eco mike,
I'm not sure that they're valves, but more like splash guards.

Pictures here.
http://jeep.off-road.com/jeep/article/articleDetail.jsp?id=257836

JohnX said:

Reed valve? Do you mean the PCV? Valve covers themselves have baffles, but I never noticed a reed valve. Maybe I'm missing something?

Do you have a picture of what you're working on?

Click to expand...

The Jeeps do not use PCV valves, nor do they call it PCV, they use a CCV system of tubing and hidden reed valves under the splash guards inside the upper part of the valve covers. Jeep calls it a CCV (Crank Case Ventilation system and tubing) instead of PCV (Positive Crankcase Ventilation). I suspect the Jeep system is atmospheric, or negative (under vacuum) and thus not a "Positive" pressure crankase vent system, but that is a guess on my part regarding the naming difference.

Sorry, I have no pictures, and the FSM's and aftermarket service guides I have seen do not seem to mention these reed valves. I know they are there because I cleaned and serviced mine (reused the old parts) last year. I have an 87 Renix Wagoneer 4.0 Jeep.

87manche said:

eco mike,
I'm not sure that they're valves, but more like splash guards.

Pictures here.
http://jeep.off-road.com/jeep/article/articleDetail.jsp?id=257836

Click to expand...

87manche,

Great pictures, thanks. One of the questions I still have is do they mount the same way in both locations, or is one flip flopped so that one acts as an inlet and the other as an outlet? There are two dirrections they can be installed in, flap up or flap down.

I do not know if they are designed to seal under excess air flow, or vacuum, or to prevent back flow in the wrong direction by closing and sealing, or if they are just splash guards, but they are very flexible leading me to believe they were intended as one way check valves as well as splash guards.

I had forgotten about the snorkles! Now I am wondering if they are part of the CCV oil problems, perhaps too long and sucking up oil from the valve floor.

This is agreat start, thanks again!

I took mine apart last year sometime to slow my air filter oil problem. From what I saw they don't actually seal up the CCV holes.
In theory the CCV system is supposed to work like this:
Manifold vacuum at the rear of the head is supposed to suck air from the front of the head from the airbox. Of course, this relies all on vacuum, and it's fragile. Any blockage in the rear and the system reverses itself, and the airbox get's dumped on.
likewise, any piston blowby that pressurizes the crankcase or any valve leakage that pressurizes the valve cover will reverse the system.
the damned thing barely works when it's in perfect working order.

Here are my thoughts. When I first saw these flappers, it occured to me that when they were new they might have layed flat and sealed until a vacuum, or positive air flow pushed the flapper open. Over time, age, sludge buildup and heat perhaps they became warped or bent and got stuck permanently open, and then Volla, they then become a pain in the arse.

If I am right they would be installed differently so that one opened down into the valve cover (the one connected to the air box) and the other opened up into the small CCV line. The air flow pressure, especially during high vacuum, would open them slightly from a normally closed (but probably not entirely air tight) position.

They are just a baffle and both mount in the open position. Cleaning the valve cover internals, including disassembly of these structures will help in reducing oil in the intake box. You also want to make sure the hoses are clean as well.

The problem with oil in the valve cover is not that it is being sucked into the box, rather that your rings are not seating as well as they once did and are allowing blowby. This pressurizes the engine space and that pressure has only a couple of places to go. First is the air box, second is the oil dipstick hole, third is the distributor shaft. By keeping the ventalation open and working, the pressure is not allowed to build up and contrary to what one might think, it reduces the oil in the air box.

old_man said:

They are just a baffle and both mount in the open position. Cleaning the valve cover internals, including disassembly of these structures will help in reducing oil in the intake box. You also want to make sure the hoses are clean as well.

The problem with oil in the valve cover is not that it is being sucked into the box, rather that your rings are not seating as well as they once did and are allowing blowby. This pressurizes the engine space and that pressure has only a couple of places to go. First is the air box, second is the oil dipstick hole, third is the distributor shaft. By keeping the ventalation open and working, the pressure is not allowed to build up and contrary to what one might think, it reduces the oil in the air box.

Click to expand...

old_man,

In my case I do not have a piston ring blowby or valve leak problem. No oil, nada, nix, zero oil getting into the air filter, box or even the large hose itself! The hoses are new. I have another thread going on right now about oil disapearing into a black hole (not the usual suspects as they all have new seals already, no blowby, no oil burning, spark plugs look new after 20,000 miles, and I mean clean and new looking!).

I am begining to suspect the small CCV line is sucking oil at a high rate into the intake manifold (last few days only). You would need to read my other long drawn out post on the recent tests I have been running, trying some synthetic oil (mix) in this engine to get the whole picture.

But to close, I was trying to focus this thread on the valve / baffle itself.

Those of you who think (or know) that this thing is just a baffle and not a valve, have you ever seen a new one??? If yes, was the the flapper piece flat against the back plate or was it bent with a fare sized gap under it like the old used ones look like?

I tried to fix the airbox with oil problem with a valve cover breather. Didn't work. So then I put a new quadratec valve cover on it. Problem fixed!!
The thing witrh the stock cover is the dummies put those tubes going down to the bottom of the valve cover. Well with the vac hooked up to the system of course its going to suck up the oil. The quadratec cover just has some plates that are screwed in. WARNING: The plates on the Quadratec cover are screwed in with 1/4" POS wood screws. When I looked at what they gave me the screw fell out!!!!! Take and retap the threads with a 8x32 machine screw tap! Also the oil cap doesnt fit. And you will have to go through the HELP section at the autoparts store to get the grommets and all that stuff correct.

87manche said:

eco mike,
I'm not sure that they're valves, but more like splash guards.

Pictures here.
http://jeep.off-road.com/jeep/article/articleDetail.jsp?id=257836

Click to expand...

X2, when I rebuilt my engine I just removed them cleaned them up and put them back in

I just cleaned up my 2.5L oil puking problem. The CCV system is just like the 6 cyl and it looks identical to the pictures in the link.

That is NOT a flapper valve, it can't move, there is a supporting piece of metal at the end to support it. Its a baffle.

The way I've read and sure appears to me, that CCV system works differently than a PCV system is that instead of using a PCV Valve, the CCV system uses an orifice.

The Orifice acts like the PCV Valve in the system to circulate air.

On mine the Orifice was clogged and the vacuum tube to the Orifice was also badly cracked. Cleaning the Orifice and fixing the broken tubes on the CCV system seemed to fix the problem for me. BUT, to be honest, I only drove the motor a hundred miles before putting it up on blocks to fix the rust holes in the floor and refurbish the suspension.

I also cleaned out the valve cover and took apart and cleaned those tubes. There were just baffles, no Reed Valves, nor could I see anything could support a Reed Valve.

I could be wrong, but if the system used Reed Valves, I think more people on the board would know more about it, as well, you think it would be better described in the manuals and literature, which I've only found talking about Orifices.

1985xjlaredo said:

I tried to fix the airbox with oil problem with a valve cover breather. Didn't work. .

Click to expand...

That is exactly what a valve cover breather would do on a CCV Jeep set up. So would large leaks at the cover gaskets, grommets and the small CCV tubing especially if it is plugged and cracked.

If you think in terms of pressure differences being the driving force behind moving fluids (air plus engine oil), and recognize that both CCV hoses to the valve cover are normally under a partial vacuum (note where they are connected on the other ends), and that the small CCV hose is normally under a higher a vacuum, and they are both normally pulling on a limited supply of blowby gases, then it only makes sense that if you supply air to the valve cover at atmospheric pressure, then that air will flow to both CCV hoses first along with large amounts of oil due to the increased air velocity caused by the large supply of high pressure air (relative to the vacuum in the two hoses).

Rick Anderson said:

I just cleaned up my 2.5L oil puking problem.

That is NOT a flapper valve, it can't move, there is a supporting piece of metal at the end to support it. Its a baffle.

The way I've read and sure appears to me, that CCV system works differently than a PCV system is that instead of using a PCV Valve, the CCV system uses an orifice.

The Orifice acts like the PCV Valve in the system to circulate air.

I also cleaned out the valve cover and took apart and cleaned those tubes. There were just baffles, no Reed Valves, nor could I see anything could support a Reed Valve.

I could be wrong, but if the system used Reed Valves, I think more people on the board would know more about it, as well, you think it would be better described in the manuals and literature, which I've only found talking about Orifices.

Click to expand...

Rick,

Puking is right! Such colorful descriptive english, gotta love it!:clap:

Anyway, How do you know that yours, the "baffles", had not been modified before you got the jeep? Mine looked exactly like a reed valve plate and reed valve (which looks like a thin flexible flat piece that lays over the opening on the plate and seals the opening until flow from the other side unseats it) where the thin piece had been bent open permanently! Of course I am not sure mine had not been messed with either since it had 225,000 miles on when I got it which is why asked if anyone had ever seen an FSM, drawing, parts list picture, or even bought an inspected a new one, because I was suspicious of the way mine looked when I inspected and cleaned them. The problem is it simply is not discussed or documented anywhere except maybe the dealers parts catalogue with part numbers.

If they are just a baffle, they sure spend a lot of money on hardware for a poor design in my book. (the baffles that is).

You are close on the difference between the PCV and CCV system. There is a bit more to it that one can deduce from the names. PCV is Postive Crankcase Ventilation, and CCV is just Crank Case Ventilation. The PCV requires some positive pressure in the crankase to force open the normally closed PCV valve. The CCV uses an always open, always flowing metering orifice as you noted already. The CCV system ventilates the crankcase much better than the PVC system which help reduce gas dilution of the oil (?) over time.

I would still like to physically see both sides of new one or at least pictures or drawings of how they should be installed or layed out.

Note that mine were bent, not flat on the thin part, and they could be installed facing up (open) or facing down (mostly closed almost sealing off the plate and gas flow).

Wish I had taken pictures of them now.

Perhaps the next person(s) to clean their valve cover would be nice enough to post some pictures of their non-valve (or valve) baffles for us all???

Of course for all I know some one might have made their own baffle/reed valve and stuck it in the valve cover of this jeep? Woudn't be the first time.

For me, getting ALL the valve cover gaskets, grommets, etc to seat and seal and getting a new 2.0 mm orifice (I am using a slightly smaller custom orifice currently) on my small CCV line has solved my oil in the filter problem for over 3000 miles, so what ever I did when I reintalled those baffles (which is how I installed them partly open all the time like a baffle) was not a problem after all.

The tick is getting all the leaks fixed, having a clean small CCV tube line with no leaks and a properly sizied orifice on that line.

For someone who has serious blowby problems they should probably use a slight larger orifice to move more air! I even toyed with the idea of using a neddle valve on mine for a while to fine tune it! Keep in mind that extra flow though the small CCV line (or a plugged no flow condition) will affect idle speed!!!

Now that I say it, think it, some with persistant low idle problems might want to check the small CCV tube and orifice for blockage! I have actually closed mine on purpose (squeezed the rubber tube closed that I have mending a broken tube spot) and watched my idle speed drop by 100 to 200 RPM!

Trust me they are baffles, not reed valves. I've done multiple.

Has anyone successfully converted their CCV system to a PCV system. Honestly, all it would take is to replace the orifice with a PCV valve. That might also require enlarging the hole in the valve cover to fit a PCV valve.

Would that have any more luck in solving the oil puking problem?

old_man said:

Trust me they are baffles, not reed valves. I've done multiple.

Click to expand...

Well then all I can say is I find their design baffling!

Rick,

Someone here (in another thread) posted a succesful PCV valve mod to theirs recently (this year), I recall reading it. But I am not sure they did not create some other problems in the process. If it is not done right, it could make the oil in the air filter problem worse.

Personally I would stick with the CCV system and just fix/clean the small line, orifice and seal the valve cover leaks. It is not that hard to do.

Correction to my prior post:

I found a post here from way back 4-5 years ago, that says CCV is Constant Crankcase Ventilation.

Also, see post #4 & #5 on PCV valve conversion:

http://www.naxja.org/forum/showthread.php?t=77342&page=2&highlight=crankcase+ventilation+hose

Could not find the one I saw recently (PCV Valve conversion), darned search engine is acting real wierd.