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.

 

[TSimage]

How would something such a the VC bellow with the dual breathers be duplicated on a Hyundai VC which has a sealed breather system underneathe the VC?

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[FORMONTOYA]

I'm betting it's a sinch, but what do you (or others) clean the PCV valve with? I just picked up a can of Gunk Engine Brite and figured that would do just fine. And I'm sure it will.

Yes, the GUNK engine brite will work just fine. I actually use just about any liquid parts cleaner so I can let the valve soak for a while before "blowing" it out.

 

[4wd-Eclipse]

How would something such a the VC bellow with the dual breathers be duplicated on a Hyundai VC which has a sealed breather system underneathe the VC?

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The two top breather lines are connected to same catch and the TOP line in this catch is connected to the bottom side of the intake pipe just after the MAF.

 

[TSimage]

The two top breather lines are connected to same catch and the TOP line in this catch is connected to the bottom side of the intake pipe just after the MAF.

I know that.

But the "upgraded" Hyundai VC are built different than the DSM VCs. The DSM covers are 100% hollow (also weaker and more prone to cracking) but the pvc simply screws in and the breather is pressed in and they both simply protrude from their openings. The Hyundai model however is different. The VC has a built in vent section to increase vaccum.

So the PVC and the preather are not visable from undernethe the head but on the Cam side they both have angled 'vents" that air is pulled/ pushed through..

 

[lenny 15]

So... I just finished reading this entire thread. If you are using the after market check valve will it work fine with a bad PCV valve? Or can I clean out my PCV valve with brake cleaner or something and have it work correctly with the after market check valve, or do I have to buy another PCV valve from the dealership?

To 4wd-Eclipse: What did you use to plug the stock breather valve on your VC, and what did do to put the dual VC breather valves in? Does it really even matter, or will the stock one work fine? I like the idea of having two breathers to relieve the extra pressure when the engine is under a lot of stress.

 

[DSMunknown]

So... I just finished reading this entire thread. If you are using the after market check valve will it work fine with a bad PCV valve? Or can I clean out my PCV valve with brake cleaner or something and have it work correctly with the after market check valve, or do I have to buy another PCV valve from the dealership?

If you're looking to buy another OEM PCV valve from one of our trusted vendors (instead of heading off to see Satan with their ridiculous prices), go back and look at post #120.

This is the remedy that this thread has brought to light:


OEM PCV valve --> catch can (Husky or something else durable) --> check valve --> Intake Manifold


If you wish to clean your OEM PCV valve that you already have, go take a look back at post #177. If you're wondering what I mean by "durable" I mean that the catch can you intend to use must be able to take some abuse. Don't use one of these catch cans between the PCV valve and the intake manifold. Go back to post #12 and read on to get more info about this.

 

[28-psi]

In reference to post #143...you are right about the Husky "small" cans not closing. It has a check valve in it. If you plug the outlet with your finger and blow it will close...but if you suck then the drain will open (no matter what way the valve is). Sort of defeats the purpose for which we are using them. My answer was a nice blue vacuum cap.

 

[95CarbonEclipse]

So... I just finished reading this entire thread. If you are using the after market check valve will it work fine with a bad PCV valve? Or can I clean out my PCV valve with brake cleaner or something and have it work correctly with the after market check valve, or do I have to buy another PCV valve from the dealership?

To 4wd-Eclipse: What did you use to plug the stock breather valve on your VC, and what did do to put the dual VC breather valves in? Does it really even matter, or will the stock one work fine? I like the idea of having two breathers to relieve the extra pressure when the engine is under a lot of stress.

I used one of my old 'el crappo' PCV valves in combo with the check valve and everything is fine. With this sort of setup, the only job that the actual PCV valve has, is it's snorkel is used to keep oil in the VC and out of your CC. The check valve takes care of all the one-way air traffic. I wouldn't bother with buying another OEM PCV valve, although it wouldn't hurt.

 

[kenamond]

I used one of my old 'el crappo' PCV valves in combo with the check valve and everything is fine. With this sort of setup, the only job that the actual PCV valve has, is it's snorkel is used to keep oil in the VC and out of your CC. The check valve takes care of all the one-way air traffic. I wouldn't bother with buying another OEM PCV valve, although it wouldn't hurt.

Actually, the PCV is also a metering orifice. It restricts airflow into the IM under vaccuum depending on the vaccuum in the IM. But as long as it's keeping oil out via the snorkel and restricting airflow as designed, it should work witth the check valve and catch can.

 

[FORMONTOYA]

Actually, the PCV is also a metering orifice.

(someone has been paying attention...cool.)


Correct, I found that out early on when I removed the PCV valve and things went to crap.

 

[95CarbonEclipse]

(someone has been paying attention...cool.)


Correct, I found that out early on when I removed the PCV valve and things went to crap.

That's true... I forgot about that. It's been months since I've brushed up on the finer details of the PCV system.

 

[bardabe]

I know this thread is old (really old) I was thinking of using a Check Valve from the brake booster, I'll give that a shot today thing is when you do a boost leak check you can only check up to 7Psi without damaging the engine (or so the write up says) but either way I'll let you guys know the results unless you guys know it wont work and tell me not to waste my time ha ha

 

[Calan]

thing is when you do a boost leak check you can only check up to 7Psi without damaging the engine (or so the write up says)

Umm... say what now?

Wouldn't it be a bit useless to only test a motor to 7psi, when it normally sees 10-20 psi in actual operation (for most people)?

I boost leak test mine to 25psi every time I do it. Are you sure you read that "write up" correctly? And where was it? Link?

 

[bardabe]

Umm... say what now?

Wouldn't it be a bit useless to only test a motor to 7psi, when it normally sees 10-20 psi in actual operation (for most people)?

I boost leak test mine to 25psi every time I do it. Are you sure you read that "write up" correctly? And where was it? Link?

here you go, Boostpro.net : Guides - DSM - Instructions for Boost Leak Test im just paranoid last time i hit 10psi and my boost leak tester came flying off my turbo inlet ha ha scary shit yo.

 

[Calan]

Wow... Ok.

I guess that makes (some.. sort of) sense if you are running 7psi max boost.

I however, am running around 20 psi. So if something is gonna be "damaged" by 7psi during a static test, you could bet your arse that 20psi during some spirited driving will separate a coupler or something.

Therefore, you need to test at the pressure that you plan to run at. (actually a little higher for a safety margin...but be safe, because things can fly apart). Start low and gradually work your way upwards as you fix leaks. AND DON'T PUT YOUR HEAD NEXT TO A COUPLER TO LISTEN FOR AIR WITH 20PSI IN THE PIPES!.. it's scary and can hurt if it pops loose... so I've heard

The first time I tested mine after buying the car and adding mods (tested at 20psi... was set for 15psi when I bought it), I had two pipes blow off at the couplers, and a bunch of leaks. Testing at 7psi, I probably would never have found them and they would have come apart while driving. I personally would rather find those problems in the garage instead of at 75mph.

The car now holds 20-25psi nicely for 30 seconds or so.

 

[FORMONTOYA]

Wow, these cars don't even come alive until after 10+PSI.

Yea, I test mine to 5PSI OVER what my setting is...20PSI...test to 25PSI, haven't ever had a problem with blowing something that wasn't ready to go.

I too would rather blow a coupler/seal/whatever in the garage than out on the street.

 

[steve]

There was some worry that the WGA diaphram might be damaged by higher pressures. Remember stock the WGA doesn't see more than the spring pressure because as soon as it opens the boost drops off. The BCS allows you to get higher boost levels but the WGA only sees about 7 psi because the rest of the pressure escapes via the BCS.

We haven't seen a problem in real use but it's still an unknown at what point it might burst.

 

[Calan]

Interesting...

I may be confused (happened once before )... but don't most people block off the MBC during a boost leak test, so that the actuator isn't seeing any pressure from the intake system at all?

When I test mine, I pull the MBC line from the j-pipe and block the j-pipe nipple with a vac cap and zip tie or small clamp.

 

[kenamond]

But the stock BCS, aftermarket bleeder-type MBCs, and ball-spring-type MBCs all have a bleeder in them, so you want to pull the compressor line off the MBC and cap it during a boost leak test so it doesn't fool you into thinking it's a boost leak (even though an aftermarket ball-spring MBC *is* a boost leak unless you plumb the bleerer air back into the intake pipe like the stock BCS setup does). I usually just kink the compressor vaccuum line with a pair of small, needle-nose vice grips during the test rather than disconnect and cap it.

So if you do that, you don't pressurize the WGA.

And all of the stock WGAs actuate at 9psi or higher, right? So one would imagine that the diaphragm can handle more than 7psi. I'm sure 50psi isn't good for it, though.

 

[steve]

The question was why that link said not to test over 7 psi. That's the reason I remember but I could be wrong as to why. I would have to assume it's a very old FAQ. If you check the FSM section on the turbo (ManualCD 90-91ECB 11-25) you see that they say not to apply more than 12.4 psi to the WGA or you may damage it.

Keep in mind that the BCS doesn't doesn't leak by default it has to be powered to open.

 

[Calan]

Thought I would post an update:

In reference to my post #143, and my smart-ass comments in #155:

The larger Husky filters don't seem to be as durable as the smaller ones. My larger one started cracking all over the place after 2k miles or so, and was so discolored that I couldn't see if it had oil or not. I've since switched back to the smaller one which seems to be stronger and able to withstand my engine bay a little better.

Remember these are NOT glass... they are polycarbonate and are not intended to see the crap we are exposing them too... so your mileage will vary.

Also, disregard what I said about using the press-lock tube fittings. After a few cycles of heat and oil the o-rings start to fail and you'll have oil leaks. The fittings I first tried were recommended for air; not oil/air... and now I know why

I now use standard brass barbed fittings with clear tubing/clamps and they work much better. I use the clear tubing so I can actually see if oil is bypassing the filter and getting to places it shouldn't.. and so far it isn't. (I just hope this tubing holds up. I may have to switch to something more durable)

 

[Calan]

For future reference...

The small plastic Husky bowls are just as bad as the large ones. The filter portion holds up well, but the polycarb bowls will crack and leak.

I fixed this crap once and for all (I hope), and I think it looks a hell of a lot better than bowls hanging in the engine bay . It was much cheaper than buying one, and you get the benefit of the filters. Oh yeah... it also holds a lot more oil than those little POS Husky bowls.

I drilled through the filter housing mounting holes, and tapped the top of the can. I then made some gaskets and screwed them down with 4-40 machine screws. The can itself mounts to the clutch line bracket, and the drain runs to a shut-off valve mounted on the lower passenger side frame for easy access when I change the oil.

Here's a few pics (I have many more if anyone is interested). I may right up a tech article if I get time, although it's pretty much self-explanatory .

Drain bung:

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Test fit:

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Holes for the sight tube:

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Ready to bolt in:

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Ready to hook up!

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[kenamond]

For future reference...

The small plastic Husky bowls are just as bad as the large ones. The filter portion holds up well, but the polycarb bowls will crack and leak.

I fixed this crap once and for all (I hope), and I think it looks a hell of a lot better than bowls hanging in the engine bay . It was much cheaper than buying one, and you get the benefit of the filters. Oh yeah... it also holds a lot more oil than those little POS Husky bowls.

I drilled through the filter housing mounting holes, and tapped the top of the can. I then made some gaskets and screwed them down with 4-40 machine screws. The can itself mounts to the clutch line bracket, and the drain runs to a shut-off valve mounted on the lower passenger side frame for easy access when I change the oil.

Holy crap Craig!

One thing I'm wondering...
If you're sharing one catch can, don't you partially bypass the PCV when the IM is at vaccuum? It seems that under vaccuum the IM will suck from the intake pipe as well as from the crank case because of the shared filter reservoir. Since the PCV valve is a metering orifice, you might have idle problems.

Or maybe it'll work super duper. All I need is a welder, band saw, and more welding knowledge.

 

[Calan]

Holy crap Craig!

One thing I'm wondering...
If you're sharing one catch can, don't you partially bypass the PCV when the IM is at vaccuum? It seems that under vaccuum the IM will suck from the intake pipe as well as from the crank case because of the shared filter reservoir. Since the PCV valve is a metering orifice, you might have idle problems.

Or maybe it'll work super duper. All I need is a welder, band saw, and more welding knowledge.

Yep... you are correct sir.

I realized that this morning when my idle LTFT started shooting through the roof. DOH! I had an idea that it may happen, but was hoping that the filters would prevent air from being sucked back in across the inputs. And I was kind of thinking that the PCV was a straight shot through the baffles to the CC breather, so it shouldn't be any different... but I haven't looked closely at how the baffling works. But anyway, it is definitely sucking air now that it wasn't before.

I think I can just rip the can and add a separator. The only problem is going to be another sight tube...Unless I just stay with the one and ASSume they are filling about evenly.

Another issue will probably be the drains. I'm wondering if there would be enough vacuum to suck oil back up through a shared drain, or if they need to be isolated as well. If the drains are tied together, they would provide another common air point, until partially filled with oil.

 

[FORMONTOYA]

Isn't it amazing how "in the wrong direction" we can make a simple PCV setup? Little did I know that this thread would turn into 7+ pages. But I sure have seen some great ideas from it.