Stupid PCV question

[FORMONTOYA]

I've gone through 2 OEM PCV (read boost leak) valves in 1500 miles since the car came off jack stands December 05. I'm tired of buying and replacing them even though they are not that expensive. I was going to pull the nipple out of the intake and put a 1/8 BSPT plug in that location and use the nipple from the intake and replace the PCV valve, however, the nipple is a press-in fit so that's out of the question. I just capped off the nipple and used the PCV valve as my nipple to "T" into the vent line going to the intake before a G-2 gas filter (catch can).

My question is why do I have to hog out the PCV valve internals? There shouldn't be a differential pressure type of thing going on, therefore the PCV valve should remain open, shouldn't it?

Below is a half-a$$ drawing of what I propose and if someone can give me a legitimate reason why it should be hogged out, I'll just order a nipple for it.

 

[oldman]

Bruce, clean out your dang pm box again. I tried to tell you that I got them in today and they're pretty solid. I blew as hard as I could and they don't leak. They crack open with only a little pressure on the other side also. Hopefully it'll work well.

Sorry Adam, you know how I'm with PMs. Instead of blowing into it, hook it up to a compressor and find out exactly when it leaks if at all.

 

[Dream On]

I'm at school right now and I don't have a compressor. I'll see if I can take them into the machine shop here though. I know they have a compressor, but I'm not sure if it's adjustable. I'll find out tomorrow.

 

[Dream On]

Update: I tested these valves today using pressurized air. I took the compressor up to 60 psi and they didn't leak one bit. I'm sure they could have taken more, but not even Shep runs more than 55 lbs of boost or so. I'll give an update to how well they do with oil and gases after I install one.

 

[oldman]

Damn it, there goes my plan to run 70 psi.

 

[romeen]

Update: I tested these valves today using pressurized air. I took the compressor up to 60 psi and they didn't leak one bit. I'm sure they could have taken more, but not even Shep runs more than 55 lbs of boost or so. I'll give an update to how well they do with oil and gases after I install one.

Can't beat it for less than 2 bucks, huh? After I've got another 500 miles or so on it I'll retest to make sure oily crap isn't causing any problems and post results. Gotta take care of my water pump, t-belt, etc. first.......damn DSM's .

 

[FORMONTOYA]

This is pretty cool. I knew that if enough people worked on this alternate setup we would be able to find something that will work satisfactorily on the "cheap" as a replacement or helper for the PCV valve.

Keep us posted about the "plastic" check valves, and good work on finding something a lot cheaper than my original idea.

 

[TSIMonsteR]

So basically this is what you are attempting, correct?: (excuse my drawing)

 

[romeen]

So basically this is what you are attempting, correct?: (excuse my drawing)

Exactly.

 

[steve]

Damn it, there goes my plan to run 70 psi.

The plastic valve isn't going to limit that. They are rated to 150psi so knock your self out.

 

[Dream On]

So basically this is what you are attempting, correct?: (excuse my drawing)

Yep, it's like two pcv valves inline. 1 good, 1 oem.

 

[oldman]

So basically this is what you are attempting, correct?: (excuse my drawing)

Now add an inline catch can between the two valves and your setup would be complete.

 

[TSIMonsteR]

mmm, this sounds interesting. Well, I am going to order this one here (http://www.usplastic.com/catalog/va...ory_name=44&product_id=21096&variant_id=22297) and a small catch can from jnz and see how that works.

 

[FORMONTOYA]

As oldman stated, just keep the catch can BETWEEN the PCV valve and the check valve. That way you don't suck in any junk into the intake from the valve cover area, and you don't pressurize the catch can.

 

[Spoolin4Ever]

As oldman stated, just keep the catch can BETWEEN the PCV valve and the check valve. That way you don't suck in any junk into the intake from the valve cover area, and you don't pressurize the catch can.

Correct me if I'm wrong (as always ...but if this thing works; you should not need the catch can, as no oil is going to get past it anyway..right?

What's the status on these things, guys? Still working good? THanks I am going to order a couple of them...tired of burning oil.

 

[kenamond]

Correct me if I'm wrong (as always ...but if this thing works; you should not need the catch can, as no oil is going to get past it anyway..right?

What's the status on these things, guys? Still working good? THanks I am going to order a couple of them...tired of burning oil.

The IM sucks through the PCV and check valve when under vaccuum. If any oil makes its way into the snorkel of the PCV, it would eventually end up in the check valve, possibly causing it to leak, and your IM. The can would catch that oil.

 

[romeen]

Since the last post I have only driven about 500 miles for a total of 1,500 miles with the check valve in place. I did a boost leak test last week and it is still holding strong. I tested (as I always do) with the PCV valve unscrewed from the valve cover but still hooked up to the IM with the check valve inline. At 23 psi I could not detect any air whatsoever leaking past it. And this is an oem PCV that I know for a fact starts to leak above 10 psi.

Admittedly, 1.5K is not alot of miles. I'll keep everyone informed as more time and miles go by. Maybe Adam (Dream On) has been able to put more miles on his car and can give an update.

 

[turbosax2]

Does anyone have any experience or theories about which of these check valves is better? Please disregard the obvious price difference.
http://www.mcmaster.com/ - part #7775K63
http://www.usplastic.com/catalog/va...ory_name=44&product_id=21096&variant_id=22297

 

[Dream On]

Why not just get this one?
http://www.usplastic.com/catalog/va...ory_name=45&product_id=15641&variant_id=64175

It's the one I tested to hold at least 60 psi, yet it's rated for 120. It's also cheaper...

EDIT: I haven't really put that many miles on my car since, but as far as I can tell, it's still ok. (maybe 5-600 miles) I need to reroute the lines to a catchcan or something since it's somewhat cramped in the area for it with the cruise control lines and everything. The lines for it are getting pinched so that can't be good. Last time I leak tested (1 week ago) it was fine.

 

[romeen]

Adam, have you done any recent leak tests to see how it is holding up? As I mentioned in post #66 mine is holding tight but I only have a total of 1,500 miles on it.

 

[95CarbonEclipse]

Does anyone have any experience or theories about which of these check valves is better? Please disregard the obvious price difference.
http://www.mcmaster.com/ - part #7775K63
http://www.usplastic.com/catalog/va...ory_name=44&product_id=21096&variant_id=22297

I've been using the one from US Plastics (the $8 one) and the only complaint i have is that it's pretty big AND for some reason the one i ordered came w/ 2 female ends so i've got some cheap ass vacuum hose smashed in there. It would be WAY better if i knew how to order the one with the 2 male ends on it. I'm going to order like 3 of the cheaper ones from US Plastics since they charge you like $8 for shipping regardless of how small the item is.

 

[romeen]

How is the function of that valve?
Have you pressure tested it to see if it leaks?
Does the size of it require you to re-route the PCV hose since the distance from the valve to the nipple on the IM is so short?

I think we are getting closer to being able to say that the cheaper valve is the way to go. After 1500 miles with the check valve:

1) I have no symptoms of pressure buildup or accumulation of blow-by vapors in the crankcase so it does not appear to interfere with proper PCV function.

2) Boost leak tests up to 25 psi have revealed no leakage past the valve whatsoever.

3) It's small size allows you to just cut the PCV hose and slip it right in without any other modifications. The ends are sized perfectly for the diameter of the stock PCV hose too.

4) $1.54 price!

Once I know that it is still functioning properly after several thousand more miles I will be able to confidently recommend it to anyone. Even if I have to replace it from time to time, the ease of install and the price still make it very appealing.

 

[95CarbonEclipse]

How is the function of that valve?
Have you pressure tested it to see if it leaks?
Does the size of it require you to re-route the PCV hose since the distance from the valve to the nipple on the IM is so short?

Yes, I have pressure tested it and it holds pressure GREAT, the only problem is if you have a sharp bend in the tubing that goes into the check valve you could have a leak at the point of entry of either hose (due to it being 2 female ends instead of 2 male ends).

It does require a bit of re-routing, but nothing real major.

After my expieriance w/ the $8 checkvalve and hearing Romeen's expieriance with the $1.50 checkvalve. I would have to reccomend that people go with the cheaper one of the two.

 

[Dream On]

I think I'm going to reroute my hoses since I think they may be kinked. It will probably end up going out towards the battery and then back to the IM. I'm not sure what I'm going to do yet exactly though.

 

[romeen]

I think I'm going to reroute my hoses since I think they may be kinked. It will probably end up going out towards the battery and then back to the IM. I'm not sure what I'm going to do yet exactly though.

I installed the check valve towards the end of the vacuum hose closest to the IM. When installed the tip of the valve comes close to touching the nipple on the IM. The check valve is positioned vertically before the hose makes it's bend towards the PCV valve. The bend is sharp but not enough to kink the hose. I think this positioning looks a little nicer and it will have a little bit of gravity assist when cracking open (probably makes no difference but it won't hurt).

 

[Dream On]

Hmm, maybe I'll have to try that.