Volkswagen Passat Forum banner

1 - 18 of 18 Posts

·
Registered
Joined
·
51 Posts
Discussion Starter #1
How can one tell if the PCV valve is good or bad. I pulled my out and it looks like there is free flow between two ports in both directions. Bad?
 

·
Registered
Joined
·
454 Posts
Are you talking about this PCV valve:



If so, you shouldn't be able to blow through it from the grey side. If so, it's no good.

If you are talking about this valve (the part at top right):



You should be able to blow through both sides. the valve closes with suction so unless you want to suck on it really hard, you won't be able to close it.


If you haven't seen it, you can see all of my PCV experience here:

http://www.clubb5.com/forums/viewtopic.php?t=71510
 

·
Registered
Joined
·
51 Posts
Discussion Starter #4
Yeah, the one at the top of the last picture. I could not figure out how this thing works. There is a small through hole between the port that connects to the air hose and the chamber of the valve, this hole is right between the turns of the spring if you look through the port that goes to the engine head. This spring inside apparently does not do anything. Another mistery is the part number. What I had was under 06A129101 (I tried two VW dealers and they could find it under this p/n), ETKA shows 034129101A, or updated 034129101B.
 

·
Registered
Joined
·
26,001 Posts
Not sure if there have been changes to the PCV valve since I learned about them
as a teen (a long time ago). The picture on top is the PVC valve.
The basic operation is:

During high vacuum,the vacuum on the metal ball overpowers the spring which
opens the valve. The pulls/vents the crankcase vapors into the cumbustion
chamber. The valve usually gums up from all of the gunk going thru it.
To check them,we used to rattle them. The spring has low pressure and the ball
should rattle when shaked. They should be cheap to relpace. I just clean mine
with carb cleaner.
 

·
Registered
Joined
·
51 Posts
Discussion Starter #6
PZ,

I am not sure I've seen a metal ball inside. Well, I've ordered a new one. Should be here in a coupler of days. When it gets here - we'll see what it should look like.
Thanks to all. :thumbup:
 

·
Registered
Joined
·
454 Posts
I replaced mine last week and it had the PN 034-129-101B but all they had in stock was the "A" so I got that one. Exact same part. Mine was all gunked up with chunks of oil bits. Much better now.
 

·
Registered
Joined
·
51 Posts
Discussion Starter #10
I was replacing combi valve this weekend and while at it thought I'd check the PCV valve as well (after reading vwfool2000's post). The valve is most probably shot, I think the water got there through the air intake. Don't have any other explanation. :???:
 

·
Registered
Joined
·
26,001 Posts
Most likely to be condensation from inside the engine.
 

·
Registered
Joined
·
51 Posts
Discussion Starter #12
PZ, this is what I thought. But there was just too much water inside. This thing was almost completely filled.
 

·
Registered
Joined
·
26,001 Posts
That would be strange to have that much water. The valve should open and
suck it into the engine. I have no idea why it did not.
 

·
Registered
Joined
·
1,161 Posts
I checked mine today. Plenty of oil inside. Should I replace it or just clean it? If this valve is'nt working how does it affect the engine?
 

·
Registered
Joined
·
26,001 Posts
If it is clogged,it will not vent your crankcase (Positive Crankcase Ventilation Valve) and you may
have a buildup of water/vapors going into the oil.
If is is stuck open,it will seem like a vacuum leak.
 

·
Registered
Joined
·
1,161 Posts
I ordered a new one today (20$). This could maybe explain my boost problem. Yes, again..... :mad:
 

·
Registered
Joined
·
26,001 Posts
Staffan said:
I ordered a new one today (20$). This could maybe explain my boost problem. Yes, again..... :mad:
If it is stuck open,it may. It is a one way valve.
 

·
PassatWorld Staff
Joined
·
12,267 Posts
The PCV valve is in the intake before the turbo compressor, so it should have no effect on boost.
 
1 - 18 of 18 Posts
About this Discussion
17 Replies
5 Participants
Rusty
Volkswagen Passat Forum
Passatworld is a forum dedicated to Volkswagen Passat enthusiasts to discuss mods, Quattro, Turbo Diesel, reviews and more!
Full Forum Listing
Top