Y breather hose & P0171 code? - VW Forum :: Volkswagen Forum
VW Forum VW Forum

» Auto Insurance
» Featured Product
Wheel & Tire Center

Go Back   VW Forum :: Volkswagen Forum > Volkswagen Models > MK4

MK4 Discussion area for the new fourth generation Golf IV, 337, R32, 20th and Jetta IV produced from 1998 to 2004.5 including Cabrio models.

VwForum.com is the premier Volkswagen Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools Display Modes
  #1 (permalink)  
Old 10-26-2009, 11:54 PM
Member
Points: 1,646, Level: 23 Points: 1,646, Level: 23 Points: 1,646, Level: 23
Activity: 0% Activity: 0% Activity: 0%
 
Join Date: Sep 2009
Location: california
Posts: 8
Default Y breather hose & P0171 code?

On my 1.8t jetta I have been getting p0171 code. I replaced MAF, fuel filter, front 02 sensor, dipstick tube, secondary air pump tubes, breather tube and "Y" breather hose. I have noticed that the Y breather hose is suctioning itself shut while the engine is running. This was the reason why I replaced it and I thought with its age that it was soft and needed to be replaced. So I replaced it and noticed that it is doing the same thing. You can really hear the pressure regulator valve sucking in. Is this a sign of a vacuum leak somewhere? Why would the breather hose suck itself flat? It idles pretty bad at cold start ups and will even die out when you make your first, second and sometimes third stops. After it warms up it idles like it is going to die but never does, but will drop to 500 and jump back to 700/800. Any ideas of thing to check. I am new to the vw world but I have started to learn from everyone on here of common problems, parts and repairs.
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 10-27-2009, 12:46 AM
TTTurbo1.8T's Avatar
No Life Outside VWforum
Lifetime Supporting Member
Points: 16,962, Level: 83 Points: 16,962, Level: 83 Points: 16,962, Level: 83
Activity: 47% Activity: 47% Activity: 47%
 
Join Date: Oct 2007
Location: East Dubuque, IL
Posts: 4,465
Send a message via AIM to TTTurbo1.8T
Default

Have you checked both the upper and lower PCV hoses for tears and holes?
__________________
Cody

Boost or GTFO

2012 Volkswagen Candy White CC R-Line 6-Speed manual
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 10-27-2009, 08:27 AM
Junior Member
Points: 48, Level: 1 Points: 48, Level: 1 Points: 48, Level: 1
Activity: 0% Activity: 0% Activity: 0%
 
Join Date: Oct 2009
Posts: 2
Default pcv valve clogged

i will bet its your pcv valve stuck, remove it and spray some carb cleaner until you hear it rattle when you shake it, put it back in and youre done
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 10-27-2009, 11:11 AM
Member
Points: 1,646, Level: 23 Points: 1,646, Level: 23 Points: 1,646, Level: 23
Activity: 0% Activity: 0% Activity: 0%
 
Join Date: Sep 2009
Location: california
Posts: 8
Default

I changed the lower breather tube and upper breather hose, so no cracks there. Is the pcv valve the pressure regulator valve which is the hockey puck looking valve? If not where is the pcv valve located? I am new to VW's.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 10-27-2009, 07:13 PM
TTTurbo1.8T's Avatar
No Life Outside VWforum
Lifetime Supporting Member
Points: 16,962, Level: 83 Points: 16,962, Level: 83 Points: 16,962, Level: 83
Activity: 47% Activity: 47% Activity: 47%
 
Join Date: Oct 2007
Location: East Dubuque, IL
Posts: 4,465
Send a message via AIM to TTTurbo1.8T
Default

PCV valve is under the intake manifold
__________________
Cody

Boost or GTFO

2012 Volkswagen Candy White CC R-Line 6-Speed manual
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 10-28-2009, 02:00 AM
Member
Points: 1,646, Level: 23 Points: 1,646, Level: 23 Points: 1,646, Level: 23
Activity: 0% Activity: 0% Activity: 0%
 
Join Date: Sep 2009
Location: california
Posts: 8
Default

i know which one you are talking about. Itts the one piece bleeder valve and it rattles. I also checked the suction jet pump also known as vacuum amplifer and that is good too. Any other suggestions?
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 10-28-2009, 07:16 PM
TTTurbo1.8T's Avatar
No Life Outside VWforum
Lifetime Supporting Member
Points: 16,962, Level: 83 Points: 16,962, Level: 83 Points: 16,962, Level: 83
Activity: 47% Activity: 47% Activity: 47%
 
Join Date: Oct 2007
Location: East Dubuque, IL
Posts: 4,465
Send a message via AIM to TTTurbo1.8T
Default

Not sure how you check it but the check valve that connects the PCV ventilation hose to the inlet pipe just before the turbo is that working fine?
__________________
Cody

Boost or GTFO

2012 Volkswagen Candy White CC R-Line 6-Speed manual
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 10-31-2009, 03:52 PM
Member
Points: 1,646, Level: 23 Points: 1,646, Level: 23 Points: 1,646, Level: 23
Activity: 0% Activity: 0% Activity: 0%
 
Join Date: Sep 2009
Location: california
Posts: 8
Default

I found out that the pressure regulator valve was clogged. The small hole that sucks in under the lip had some build up in it. I soaked it in rubbing alcohol and then, no more flat suction y breather and no more P0171. At least for now. I had no other leaks and evrything else is good.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 10-31-2009, 05:32 PM
TTTurbo1.8T's Avatar
No Life Outside VWforum
Lifetime Supporting Member
Points: 16,962, Level: 83 Points: 16,962, Level: 83 Points: 16,962, Level: 83
Activity: 47% Activity: 47% Activity: 47%
 
Join Date: Oct 2007
Location: East Dubuque, IL
Posts: 4,465
Send a message via AIM to TTTurbo1.8T
Default

Yeah that's the valve I was thinking of...good to know...I'm willing to bet this is a common problem with higher mileage cars.
__________________
Cody

Boost or GTFO

2012 Volkswagen Candy White CC R-Line 6-Speed manual
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 10-31-2009, 06:28 PM
Member
Points: 1,646, Level: 23 Points: 1,646, Level: 23 Points: 1,646, Level: 23
Activity: 0% Activity: 0% Activity: 0%
 
Join Date: Sep 2009
Location: california
Posts: 8
Default

After reading all the post from people just ruling these out and how they say that they aren't important, I just thought the same thing. But in my case it wasn't functioning correctly and its easy clean, but when you check them it might act like air is flowing in all directions but It can still be restricted. So it can also be a cause of lean codes. Its that small little hole that can cause the problems. It sucked because I even had vw techs overlook it too. They are suprised now and glad they know.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 08-13-2010, 09:32 AM
Member
Points: 7, Level: 1 Points: 7, Level: 1 Points: 7, Level: 1
Activity: 0% Activity: 0% Activity: 0%
 
Join Date: Aug 2010
Posts: 3
Default

Where is the pressure regulator valve located?
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 08-13-2010, 10:03 AM
Evolved Member
Points: 4,236, Level: 41 Points: 4,236, Level: 41 Points: 4,236, Level: 41
Activity: 7% Activity: 7% Activity: 7%
 
Join Date: Jun 2009
Posts: 679
Default

Quote:
Originally Posted by arthur solalinde View Post
Where is the pressure regulator valve located?
Arthur - from the Y breather hose at the top of the valve cover follow the hose that routes toward the back of the engine. It will terminate at a "hockey puck" looking thing which locates onto the big pipe next to the MAF sensor. It sits next to the diverter valve.
Funny, I read a lot about the PRV yesterday. I was thinking of changing it pre-emptively.
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 08-13-2010, 10:52 AM
Member
Points: 7, Level: 1 Points: 7, Level: 1 Points: 7, Level: 1
Activity: 0% Activity: 0% Activity: 0%
 
Join Date: Aug 2010
Posts: 3
Default

oops, im sorry, this is for a 01 1.8t passat. is it the same location?
recently i accidentally installed a K&N air filter soon after that i rcvd a system too lean code, i was told K&N was a no no for vw's. could the oil on the filter ruined the MAF sensor?
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 08-13-2010, 10:59 AM
Evolved Member
Points: 4,236, Level: 41 Points: 4,236, Level: 41 Points: 4,236, Level: 41
Activity: 7% Activity: 7% Activity: 7%
 
Join Date: Jun 2009
Posts: 679
Default

My first thought was the PCV valve. The vent hole in the PRV is pretty small, I'm suprised that it could suck the y-hose flat - I would have thought that maybe some crud is stuck under the diaphragm in the PRV that is not allowing a good seal between the PCV side and the turbo inlet pipe. Anybody know if you can you reach inside the valve to clean the diaphragm?
I just replaced all my breather hoses with silicon ones as the regulars on the forum know. When I pulled the old hose of the PRV there was a lump of dried oil crud sitting in the end of the hose - it was like a small piece of coal about the size of a small pebble about 3/8" diam. This is why I started to read up on what the PRV does.
I'm likely going to replace mine and upgrade the DV to the Audi TT 225 hp one soon.

Last edited by AgGTI; 08-13-2010 at 11:07 AM.
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 08-13-2010, 11:05 AM
Evolved Member
Points: 4,236, Level: 41 Points: 4,236, Level: 41 Points: 4,236, Level: 41
Activity: 7% Activity: 7% Activity: 7%
 
Join Date: Jun 2009
Posts: 679
Default

Quote:
Originally Posted by arthur solalinde View Post
oops, im sorry, this is for a 01 1.8t passat. is it the same location?
recently i accidentally installed a K&N air filter soon after that i rcvd a system too lean code, i was told K&N was a no no for vw's. could the oil on the filter ruined the MAF sensor?
I've had a drop in K&N filter for the lifetime of the car - I'm still running the original MAF after 8 1/2 years. The K&N is fine as long as you don't over oil it after you clean it.

I'm not sure about the PRV location in your Passat, sorry. I would try and follow the hose that comes off the Y-breather hose and see where it goes. It should end up in the hockey puck PRV on top of the Turbo inlet pipe right after the MAF sensor. Don't know if VW had a different arrangement in 01. Somebody else might chip in. Also, don't confuse it with the diverter valve (DV) which is a similar shape but has a small vacuum hose connected to the top of it.

Your too lean code might be more related somehow to your breather hoses being sucked flat.

Last edited by AgGTI; 08-13-2010 at 11:09 AM.
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply

  VW Forum :: Volkswagen Forum > Volkswagen Models > MK4

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the VW Forum :: Volkswagen Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
breather hose from 3-way hose... PRican MK4 0 07-18-2009 03:39 PM
replaced breather hose and now it runs funny? sensesfail99 MK3 0 07-07-2009 01:46 PM
Breather Hose jcrews21 MK4 3 03-15-2009 07:30 PM
Mass Flow Issue? Broken Hose?? Picture of Hose. Help me Indentify this part.... paguy717 MK4 7 02-22-2009 10:25 PM
breather hose manborn MK3 1 03-24-2003 11:50 PM

Powered by vBadvanced CMPS v3.2.2

All times are GMT -5. The time now is 08:40 AM.


Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.3.2
Garage Plus vBulletin Plugins by Drive Thru Online, Inc.
VWforum.com is a Volkswagen/VW Forum and enthusiast site and is not associated with VW/Volkswagen in any way.