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.

 

[FORMONTOYA]

Nice pictures of a clean install.

Is that a pressure sensor for logging on the AFPR?

 

[4wd-Eclipse]

Nice pictures of a clean install.

Is that a pressure sensor for logging on the AFPR?

Thanks

That is GReddy fuel pressure gauge sensor .

 

[nightspeed87]

On my awd 1g

the pcv and intake vaccum line has two thick long hoses that are just hanging down towards the ground in near the back of the engine with no filter or nothing on them. The intake mani pcv port has been sealed, and the intake arm hole has been sealed. Anything wrong with doing this?

The motor has 86k on block and like 12k or something on the head which was freshened up.
The motor has good compression but a little blow by under boost and it burns a little oil.. Like 1 qt every 500 miles ( a good amount of boosting during that time. ) So id translate that to being about 1 quart a month.
The dipstick has never popped out though ( The turbo is fairly new )...

 

[funguy]

Just to show some pics on my new 2 oil catch cans setup ...

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Sorry to bring this back up. But that is exactly what i was looking for. Where did you find those mini catch cans? I just built motor, and it is getting a ton of blow by @ idle which is making me burn a ton of oil. Please let me know where you get those pieces.

Derek

 

[4wd-Eclipse]

Sorry to bring this back up. But that is exactly what i was looking for. Where did you find those mini catch cans? I just built motor, and it is getting a ton of blow by @ idle which is making me burn a ton of oil. Please let me know where you get those pieces.

Derek

Derek, the catch cans are custom made from 8" long 2.5" metal pipe with 3 pieces of 3/8" NPT weld bungs in each catch. All the fittings are from Summit and the check valve (part # 64175) is from usplastic.com and the 8mm and 10mm silicon hoses from ExtremePsi.

 

[blcknspo0ln]

OK I have food for thought. This is the way I had it hooked up before and it SMOKED LIKE CRAZY. My solution was to eliminate the PCV valve. I originally thought it was a bad PCV valve (which only had 6k miles btw), but then I bought a new autozone one and it smoked just the same.

JMF SMIM > PCV

VC > greddy catch can > intake pipe

Throughout all of the debates and debacles I've read through, that is stock operation and should have worked. WRONG. The new setup I have on there does not give any smoke on or off boost. The PCV has been eliminated in favor for a straight through fitting found on a stock intake manifold (the one where you connect the brake booster line to).

So my question is, why did it smoke with the "correct" hookup, but not with the removal of the PCV?

 

[Dream On]

My guess is the Autozone one you replaced it with was also bad. OEM is the only way to go as the Autozone ones leak right out of the box. Did you test the new one?

 

[95CarbonEclipse]

On my awd laser

the pcv and intake vaccum line has two thick long hoses that are just hanging down towards the ground in near the back of the engine with no filter or nothing on them. The intake mani pcv port has been sealed, and the intake arm hole has been sealed. Anything wrong with doing this?

YES!! By running your setup this way you aren't creating the necessary vacuum to effectively remove blow by gasses.

Under boost your turbo is sucking air through the intake (which should have a hose connected to the VC on the side), this sucks blow by gasses out of the VC and recycles this metered air back into your IM. At the same time, a properly functioning PCV valve is blocking the compressed (boosted) air from entering into the VC.
Under Vacuum (or idle/coasting) your properly functioning PVC valve opens up to allow the IM to suck the blow by gasses out of the VC and recycles them back into the IM.

So... you can see that by running the setup quoted above, BLOW BY GASSES ARE NOT BEING REMOVED FROM THE VALVE COVER. What's happening is that they're just sitting inside your VC and eating away at your oil and your valve seals. Sure you're not going to see a whole lot of smoke out the tailpipe, but that doesn't mean that it's working.

 

[95CarbonEclipse]

My guess is the Autozone one you replaced it with was also bad. OEM is the only way to go as the Autozone ones leak right out of the box. Did you test the new one?

You're absolutely correct! The Autozone PCV valves ar POS. They don't even function right out of the box. Your best bet is to hook your PCV system up correctly and add a plastic check valve from US Plastics between your Autozone PCV valve and your IM (it doesn't matter if your PCV valve is working properly or not if you use a third party check valve. All the PCV valve is doing now is allowing the correct amount of blow by gasses out along with using it's 'snorkel' to keep your oil in the VC and out of your IM). If you want to use a catch can put it between your IM and the check valve and another between your VC and your intake, just like in 4WD-Eclipse's post. That will get you the correct, properly functioning, low-maintainence, results you're looking for.

BTW... 4WD-Eclipse, that looks effing great. The problem i'm having is finding room to mount my catch can neatly. I'm offically jealous.

 

[TSIMonsteR]

OK I have food for thought. This is the way I had it hooked up before and it SMOKED LIKE CRAZY. My solution was to eliminate the PCV valve. I originally thought it was a bad PCV valve (which only had 6k miles btw), but then I bought a new autozone one and it smoked just the same.

JMF SMIM > PCV

VC > greddy catch can > intake pipe

Throughout all of the debates and debacles I've read through, that is stock operation and should have worked. WRONG. The new setup I have on there does not give any smoke on or off boost. The PCV has been eliminated in favor for a straight through fitting found on a stock intake manifold (the one where you connect the brake booster line to).

So my question is, why did it smoke with the "correct" hookup, but not with the removal of the PCV?

I don't see a reason why you current set up wouldn't work fine. Connected to the Intake Pipe, would the turbo not suck out any gases in the VC? Or, would it suck too much creating a vacuum in the VC?

 

[95CarbonEclipse]

I don't see a reason why you current set up wouldn't work fine. Connected to the Intake Pipe, would the turbo not suck out any gases in the VC? Or, would it suck too much creating a vacuum in the VC?

Oh it'll suck out the blow by just fine while under boost, but not while idling or vucuum. Under vacuum the blow by will just linger in the VC. It's not the worst setup in the world, but it's not correct. The reason it doesn't smoke like this is that under boost the IM isn't forcing air into your VC and pushing oil past the seals.

Again, just because it isn't smoking doesn't mean that it's working correctly.

 

[blcknspo0ln]

I never said it was the "correct" way of hooking it up, just that it cured my smoking issue. With the "appropriate" way (may or may not have had a fualty pcv), the car smoked at idle, cruise, AND boost. I'm asking for an explanation, if anyone has one.

 

[TSIMonsteR]

Even at idle, shouldn't the compressor be spinning a little? Now , even at idle, the TB is open a little, so whats the diff between having it pre or post TB?

Just trying to learn...

 

[dsm-onster]

On my awd laser

the pcv and intake vaccum line has two thick long hoses that are just hanging down towards the ground in near the back of the engine with no filter or nothing on them. The intake mani pcv port has been sealed, and the intake arm hole has been sealed. Anything wrong with doing this?

The motor has 86k on block and like 12k or something on the head which was freshened up.
The motor has good compression but a little blow by under boost and it burns a little oil.. Like 1 qt every 500 miles ( a good amount of boosting during that time. ) So id translate that to being about 1 quart a month.
The dipstick has never popped out though ( The turbo is fairly new )...

I'll answer this older question. I have run setup like this w/ no ill effects other than "blackening" my oil earlier than usual. I wouldn't recommend this for a DD unless you change your oil every 3K or so. The vapors in the block are not sucked out by vacuum when in cruise or idle, so they settle in the oil pan and blacken the oil. This is grit. and is not good for the block. I don't run my car frequent enough anymore to fix this. I will as soon as this car has to back up another or is going to be put back on the road as a daily driver.

 

[95CarbonEclipse]

I never said it was the "correct" way of hooking it up, just that it cured my smoking issue. With the "appropriate" way (may or may not have had a fualty pcv), the car smoked at idle, cruise, AND boost. I'm asking for an explanation, if anyone has one.

Most likely due to bad valve seals, especially if your PCV valve wasn't working properly. That along with infrequent oil changes will damage your seals very quickly, but even with regular scheduled oil changes a bad PCV is absolutely horrid on valve seals. I think that's why DSM's are so well known for having bad seals. Because, even the OEM PCV valve won't hold up to 5,000 miles, and then if you replace it with an Autozone/Shucks/etc. PCV valve, you're not really fixing it. By the time you're seeing smoke, the damage is done.

 

[95CarbonEclipse]

Even at idle, shouldn't the compressor be spinning a little? Now , even at idle, the TB is open a little, so whats the diff between having it pre or post TB?

Just trying to learn...

You're right... it doesn't matter at all if it's before of after the TB, the turbo is what is important. Check with anyone running a GM MAF. Those guys have problems because they can't get a PCV system that functions properly without losing metered air.

You've got to have one pre turbo and another post turbo in order to suck out blow by during both vacuum and boost.

 

[kenamond]

blknspo0ln: Any chance the baffles in your VC are modified/removed? I don't understand why you'd get smoke in all cases with the PCV and none without. Under boost with a bad PCV, you can smoke from boosting your crankcase, but at idle, the only thing I can think is that your PCV is sucking oil from the VC and you're burning that oil.

For sure, if you got an Autozone PCV, it will not hold boost; it wasn't designed for boosted applications, so that may explain smoke under boost with the PCV.

If the baffles in your VC have been removed, you can splash oil into the PCV snorkel.

I'm wondering if the smoke under idle is just burning the oil that's settled in your IM or is left over from boosting your crankcase.

You might try putting in an OEM PCV, cleaning the vaccuum line to the IM, doing a boost leak test (to make sure it holds - some OEM ones leak out of the box), and then see if you get smoke. If you do, check the vaccuum line for oil.

But the solution that was posted by 4wd-Eclipse includes a catch can, so you could restore the PCV system and catch the oil drawn through the PCV if that's the problem.

 

[4wd-Eclipse]

Mack ... do you think the OEM PCV operation will be effected or oil will be sucked into IM during idle or under boost by drilling some small holes 3mm diameter in VC baffles? ... This is what I did.

 

[TSIMonsteR]

Is there a good website that carries OEM PCV valves? Or is going to SATAN Mandatory?

I am going to order like 10 or so and just start replacing them as soon as they leak (or every other oil change or so)

Right now mine is a Purolator and leaking.

 

[DSMunknown]

Is there a good website that carries OEM PCV valves? Or is going to SATAN Mandatory?

I am going to order like 10 or so and just start replacing them as soon as they leak (or every other oil change or so)

Right now mine is a Purolator and leaking.

Click here or here.

 

[Dream On]

Just order one OEM pcv and then get one of the cheap plastic check valves. I've had good luck with mine so far.

 

[TSIMonsteR]

Thanks a lot man. Just to think, I actually searched ExtremePSI for the Keyword "PCV" and came up empty. Favorite site to order from, thanks.

 

[blcknspo0ln]

blknspo0ln: Any chance the baffles in your VC are modified/removed? I don't understand why you'd get smoke in all cases with the PCV and none without. Under boost with a bad PCV, you can smoke from boosting your crankcase, but at idle, the only thing I can think is that your PCV is sucking oil from the VC and you're burning that oil.

I haven't figured out the exact problem, seeing how my VC was with me since stock (so no removed baffles or anything), but I know that I will be "customizing" my VC rather soon. I bought a new one and will be blocking off the stock middle breather port and will be drilling/tapping/installing 2 3/8" brass fittings for a double vent and will be reinstalling stock PCV. Hopefully the extra vent port, along with the PCV back in place, will be enough to cure my problem (the right way).

 

[Calan]

Was looking through this old thread (about to redo my PCV system), and noticed something I hadn't seen before. What is the other line coming off the VC in the pic that was posted a while back? (I highlighted the one in question in yellow).

 

[oldman]

That's the other nipple on the VC, how's yours hooked right? Not VTA I hope!!!!

































Just kidding, he drilled and tapped an extra fitting on the VC.