PCV's got Me Beat

[BobbyShaftoe]

I'm a bit stumped... again. I'm trying to fix a slight roughness in my German Princess' idle. I mostly just can't find the actual PCV valve. I was digging around under the manifold, playing with that octopus that lives under there like a troll. There was no way that that connection was coming apart without tearing something.
I've got a "PCV valve" i got from the parts girl at my indy , but there is no way it's fitting into the stub coming off that rubber T style fitting that comes off the breather tube. I've found a couple diagrams that show some kind of valve in there, but I must have the wrong one, because it is way too big to ever go in there ..... I think. And I can't get that connection apart. Any pointers? That thing was a real bitch to even get close to... I really don't want to take off the intake manifold.

As far as that rough idle, I'd love some help with that too.
I've done a ton of searching and trouble shooting and I'm pretty sure I haven't got any broken/leaking vac lines, I've replaced the crank case ventilation valve ( is that right?, the "hockey puck" coming off the turbo inlet air hose) but not the check valve beside it, replaced the plugs and the coils, cleaned up the ground lines on the injector harness, checked the air filter and new MAF for cleanliness, cleaned the already spotless throttle body and air intake sensor, cleaned the MAP sensor, re-seated and checked every electrical connector.
There's a couple weird things I've noticed about the PCV system that makes me think this is the culprit: when I first examined the hockey puck thing, it was full of mayonaise and other assorted crud (cleaning didn't make much differance) and then this week, when I took it apart again to install the new one, there was already a couple teaspoons worth of water in it. Where the hell is that coming from?
So, I'm at the point where the PCV and maybe the suction jet pump are my last recourse before I send my injectors in for reconditioning. Except I can't find the damn PCV.....
I guess in need to buy a vac pump testing thing....

edit: 1.8T ATW

[aeb-reid]

Easy access for that area would be to pull the coolant resiviour and lay it over(leave the lines hooked in.) I was under the impression there was no actuall pcv valve on the passat. ( Volkswagen Passat B5 FWD 1.8T > Search > Pvc Valve > ES#2093820 Pressure Control Valve (PCV) - (19mm) - 035103245A )There is a 1 way valve. And then the hockey puck valve for the crankase. If you wanna stop the crud and water from going back into the intake get a catch can and vent it to atmosphere. You have a lot of info in you message and I've had a bit to drink so if i missed a question ask directly lol.

[BobbyShaftoe]

yeah! that's the exact one I've got! Except mine is wider around than the hose I think it goes into. Or i'm looking at the wrong location.

I did tip the coolant tank forward, I had the TB off too. It was still a really tight fit.

So, is that amount of water normal? As cold as it is where I live, that kinda gives me pause.... water tends to freeze solid in no time around here.

[aeb-reid]

Yeah it's normal. Vw likes to pump crank vapors back in. My wife's Beetle is the same way. I drain some gross white/brown milky liquid weekly. You should look up a sai delete and a catch can install. Clean up your bay and have a lot less crap to deal with. I don't Think there would be a freezing problem bc most I the liquid would et caught in you intercooler.

[TurboJim]

... when I first examined the hockey puck thing, it was full of mayonaise and other assorted crud (cleaning didn't make much differance) and then this week, when I took it apart again to install the new one, there was already a couple teaspoons worth of water in it. Where the hell is that coming from?

Water vapor is a by-product of combustion and is present in blow-by gasses. Moisture and oil mix to form the mayonaise substance you are seeing. This is more noticable when the vehicle is used for short trips and oil temperatures are lower.

[forcedfx]

Ah yes, I just did this a couple days ago on the wife's 2000 ATW. The PCV is inside of that "rubber T adapter" that comes off the engine crankcase pipe and is clamped inside. One of those metal pipes that runs across the back of the engine and over to the exhaust side goes into it as well. I had to pull the intake manifold to get to it. And I'll tell you what, even with the IM off it was a bitch to get it apart and then back together again. I had to cut the remains of that T adapter off of the metal pipe.

I could have finished the job in no time but the metal pipe was completely blocked solid with carbon. Even my compressor couldn't force air through at 90 psi. I used a coat hanger and reamed it in and out to break up as much as I could. Then I did multiple soakings of straight purple power which eventually dissolved away the carbon. I love purple power. It works awesome. I could have bought a new pipe but it would have meant borrowing her mother's car and spending $51 plus shipping.

Anyway, it's back together and I'm not sure of whether the car is running better or not but I guess we shall see. Now I have to replace the valve cover gasket. I'd recommend saving yourself some aggravation and just pull the manifold. Luckily not too much of the coolant drains out. Maybe 3/4 of a gallon?

Let me know if you have any questions on the PVC. It's still fresh in my head.

[BobbyShaftoe]

Thanks for the pointers, guys. I'm going to remove the intake manifold next go round.
As for that water, it's good to know that it's normal. 95% of the driving I do is short trip. Usually only long enough to get the thermostat showing 190, but not long enough to get the coolant system flowing. I hate doing it as I know that short trips that don't get the engine up to temp are the worst thing in the world for any motor, but what are ya gonna do?

Whatever I managed to do yesterday, I've set myself back at step or two. I started out trying to get rid of a faint tremor in the idle, but now I'm throwing random multiple misfires and misfire codes for cylinders 3&4, and the thing is running like shit. The first start this morning just about made me crap my drawers, it smoothed out eventually but now the idle's gotten really erratic. I must have torn the valve housing messing around with it yesterday. Jeez, I hope all that is caused by something I did yesterday and not a new issue....

I'm ordering up the whole replacement PCV system from o34motorsports. I hope it gets here soon.

[mrbutterz]

If you have access to an air compressor, search on here for how to make a "boost leak tester," that could help determine if you have a broken PCV hose or check valve anywhere.

when was the last time your spark plugs were changed? do you think that they or the coils could be part of the problem?

Though its time consuming, you;ll thank yourself after you pull the IM

[nolesfan]

Though its time consuming, you;ll thank yourself after you pull the IM

I didn't and wished I did once I did it the hard way. At least I didn't have to catch any coolant, but I probably cost myself an extra couple hours.

[BobbyShaftoe]

If you have access to an air compressor, search on here for how to make a "boost leak tester," that could help determine if you have a broken PCV hose or check valve anywhere.

when was the last time your spark plugs were changed? do you think that they or the coils could be part of the problem?

Though its time consuming, you;ll thank yourself after you pull the IM

Both the plugs and coils are brand spanking new. The new coils cleaned up a very slight, erratic hitch in the idle but left me with a very faint rolling tremor in the idle that was driving me nuts. Thats why I started messing with the PCV system....


I've seen a boost leak detector here before, but it didn't occur to me that it would help with the vacuum system... now that I'm thinking of it, I guess both systems are intertwined. Is it nothing more than a PVC end cap with a nipple in it? Clamped into the air intake tube at the turbo? What the max PSI I should use? I'm guessing not much more than about 20 psi?

Edit: I found this: http://www.a4mods.com/index.php?page...tml&category=5 but it shows the "hockey puck" disconnected... wouldn't that seperate the PCV system from the intake system, and not tell me anything, unless I have a boost leak?

[mrbutterz]

^^ Yes that is the thread I used when making my tester. Try it, and they recommend to run between 10-12 psi. Also, you disconnect the Puck valve in order to prevent pure, unburned oil from going into the turbo and thus burning when you start the car next. The car normally only returns an oil and air mixture into the TIP and thus you don't have to worry about burning blue smoke...

Also, this puck valve is the last part of the PCV, the rest of the pcv system will still get pressurized by the intake manifold, the crankcase etc.

[nolesfan]

At leasg doing my catch can should keep me from plugging mine.

[BobbyShaftoe]

At leasg doing my catch can should keep me from plugging mine.

I gave this a lot of thought.... my indy talked me out of it with the vague phrase: "it can cause problems". I personally don't care one way or the other, I just want to avoid anymore "problems". Installing a catch can or dealing with the PCV once ever 100 000 km.... Hell, I'd go old school and forget the catch can and just dump it onto the road, and if it was an old Ford, then hell ya, I'd delete it and forget it. I've seen catch cans running close to $200 though, plus plumbing, and I don't get what there is to gain. I guess what it boiled down to for me was that this motor seems pretty touchy, and I ain't no mechanic so the closer I keep it to it's original operating parameters, the better off I am.

[mrbutterz]

I gave this a lot of thought.... my indy talked me out of it with the vague phrase: "it can cause problems". I personally don't care one way or the other, I just want to avoid anymore "problems". Installing a catch can or dealing with the PCV once ever 100 000 km.... Hell, I'd go old school and forget the catch can and just dump it onto the road, and if it was an old Ford, then hell ya, I'd delete it and forget it. I've seen catch cans running close to $200 though, plus plumbing, and I don't get what there is to gain. I guess what it boiled down to for me was that this motor seems pretty touchy, and I ain't no mechanic so the closer I keep it to it's original operating parameters, the better off I am.

Ya it's up to you, obviously you don't have to run with a can although I'm really not sure what problems your mechanic was referring to... If installed correctly (allows for crankcase AND valve cover ventilation) then there really aren't any problems to be had. I have been running mine for almost a year now with no problems. On top of that, though I agree these motors can be touchy, with a recirculated can the system would be set up and run 100% normal, just as it currently is, the only difference is the can would separate the oil and air before the TIP. Regardless of how touchy the motor may be that setup would not pose any threats.

One of the main benefits I would see for you would be to prevent your puck from having that milky "mayonnaise" stuff in it again. This in tern would slow down the wear and tear on it as well as the rest of your PCV system and help prevent it from clogging up. You could also do the instillation yourself in order to lower that cost (if you felt comfortable removing the IM then installing a can would be a walk in the park) and if you really wanted you could make a can for cheap though I'm sure there are other cans for less than that $200ish mark.
If you want to know more about the can and possibilities with it just search and ask away.

btw: ya you could actually go old school and just dump it if you really wanted...

Either way, right now a can isn't going to solve the problem you currently face, after you run your boost test (and hopefully find a leak) and repair what ever problem is currently causing this, then I would look into a can as a preventative measure.


Outside of this PCV and can stuff, if this doesn't fix the issue I can't think of what else it might be besides a fuel issue, which seems to be the only aspect you have yet to address with the car. Do you remember anything happening to/with the car before this rough idle started? Timing Belt job, possibly dirty gas, bottomed out, wreck etc?

Fuel wise I would maybe start with the fuel filter. That would be cheaper than the injectors and couldn't hurt. You may also want to try injector cleaner or even trying autoRX or seafoam.

[nolesfan]

Maybe catch cans can pose problems if not cleaned out every so often; it wouldn't be good to let them fill up then that crap gets sucked in as liquid! I installed mine inline with the PCV system as a means to keep out as much garbage as I can. It cost a little over $100 (42 draft designs stealth catch can) and I just bought heather hose and clamps to install it myself. I've had it in something like 350 miles so far, but when I change my oil tonight I'll open the valve and see if anything comes out. My guess is very little if anything is coming out tonight since the valve isn't on the dead center bottom of the can, and my 22 mile commute is mostly highway averaging probably 50MPH each way, so I shouldn't get anything more than some oil vapors in there yet.

[BobbyShaftoe]

Installing it in-line huh?
That's a good idea. I think that's what I'll do, especially since I ordered the 034 motorsport PVC system on Monday. I did find a cheapo catch can on fleabay that will work well enough for my needs. Thank you both

So here's a dumb question: these catch cans.... are they sealed against vacuum? I think I've seen them with some kind of breather vent and I also think I've seen them without, looking like a sealed unit. I think the cheap one I found on ebay is the one with the breather vent. I'm assuming that one installed as part of the system would have to be vacuum proof, but I will admit to never having gotten a grasp of the whole automotive vacuum thing.

[nolesfan]

For instance with mine, there is one line in that I've fed from the valve cover and crank, then the other line feeds into PRV. The turbo creates the vacuum under boost, which pulls air into the catch can, filters it and then into turbo/intake.

[BobbyShaftoe]

I'm googling the shit out of it right now.


um... duh.... what's a PRV?

[birdman829]

PRV is the pressure relief valve or something like that. It's the hockey puck shaped valve that goes into the turbo air hose from the crankcase ventilation tube

[BobbyShaftoe]

Thanks. Seems so obvious when you say it like that :7

I'm starting to think about an air compressor type oil seperator, with a petcock and mounted in the long line that replaces the hard line that runs over behind the motor.

Nolesfan, got any pics, by any chance?

[nolesfan]

Of my catch can, yes. Of a pet's cock, no.... LOL.

I'll post links or pics tomorrow when I'm not on my phone. Feel free to ask any questions about it. Where I mounted my catch can is a little too close to the oil filter, but oh well.

[BobbyShaftoe]

Of my catch can, yes. Of a pet's cock, no.... LOL.

I'll post links or pics tomorrow when I'm not on my phone. Feel free to ask any questions about it. Where I mounted my catch can is a little too close to the oil filter, but oh well.

LOL! oh, the things I say sometimes. Sorry. hahaha

[mrbutterz]

For instance with mine, there is one line in that I've fed from the valve cover and crank, then the other line feeds into PRV. The turbo creates the vacuum under boost, which pulls air into the catch can, filters it and then into turbo/intake.

So, this ^ is the closed or return example, comes from the crank and the VC, into the can and then into the puck vlave (PRV) and finally into the TIP, all without ever venting into the atmosphere.

Mike, hope you don't mine but I pulled the pics you sent me of your setup.

Mikes (nolesfan) engine:


His can, under the coolant tank:


From the can, the air runs into his PRV shown here and then into the TIP



My setup (if you care to know the differences) is the vented style. I run from the vc and the crank case directly into the can which vents the air into the atmosphere, no PRV and no return to the TIP



Either way works. Most seem to prefer mikes method of returning. As he mentioned, when under boost the turbo creates a vacuum and can pull air from the vc and crank but obviously that does not have to occur for them to still vent. Instead of my turbo pulling air from them, they both vent naturally.

[MirceaM]

very original hood latch mrbutterz

[nolesfan]

Nope, I don't mind you posting mine at all. Easier than me having to take the time

As you can see, either works fine, though long term I obviously have no results yet as it's only been on there less than 2 weeks. I will say where I've mounted mine makes it more difficult to change the oil filter.

[mrbutterz]

very original hood latch mrbutterz

ya... thats a coat hanger, and my latest "mod"

I bought the car in 2008, since then i've gone through 3 of the OEM plastic latches and 2 lanyards with metal connections. I finally decided I've had enough, took the latch apart and wrapped this around the little hole on the pin that you pull so it will not come loose again. When the hood is closed you cant see it at all

Mike, I'm starting to feel like you and I have become the forums unofficial spokespersons for catch cans

[BobbyShaftoe]

boy oh boy, those are some clean looking engine bays.

[nolesfan]

Thanks! I must admit mine looks shinier in picture than in person, but I do keep it clean. I just wipe it down each time I was the car and that actually takes care of most of it.

[BobbyShaftoe]

Further developments:
Built me up a Boost leak detector thingamajig. Made it out of an empty throttle body cleaner can I just happened to have lying around, and a couple of air hose nipples and some washers and shit I had, also just lyin' around. I've gotta admit, I was a bit nervous the first time I shot some air into it, and a little surprised at the results. Of course, I have no idea what I'm doing....
Here're the results, hope you guys can make sense of this.
I could see the TIP swell up a bit and hear and feel the air moving into the system. There was no obvious sound of air leaking out anywhere, except that after a few seconds, I could hear the air bubbling up through the oil in the crank case. If I took the dip stick out, I could feel it release the pressure through that opening. With the dip stick in , I could feel the air come out when I took off the valve cap, and then, with both of those plugged up and my thumb in the end of the PCV hardline, I could feel pressure build up.
So I guess I don't have an actual leak out to atmosphere, I'm thinking that hidden little bugger of a PCV valve is maybe just not working right. I'm not sure air should be leaking out into the crank case and bubbling through the oil... is it? Am I right in thinking that all the other little vac lines are good too?

[mrbutterz]

^^ wow, I;m actually surprised at this. I thought for sure you'd have a leak somewhere. IIRC it's of no concern that the air would reach the oil in the crankcase. When the engine is running oil travels from the pan, through the crank and up into the valve cover so it makes sense that air would be able to circulate throughout the system as well.

I would have to agree that the PCV valve under the IM would be the next logical step. And I would also assume that this would prove all other PCV lines (as well as your check valves) to be in good working order.