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View Full Version : DIY: DIY: 3.0 PCV Replacement



JEENYUS
04-16-2012, 03:08 PM
I ran into the issue of my bad PCV just the other day. I have seen only really one post about it even after searching, but figured it could be useful for anyone in the future who needs to locate and replace their own PCV for the 3.0.

Tools Needed:

Flathead Screw Driver
WD-40

Time: 10-20 min

First thing you will want to do is take off the cover located at the top of your engine.
http://i1253.photobucket.com/albums/hh593/jeenyusz/IMG00289-20120410-1811.jpg

The PCV is located on the driver side of the engine bay just under the engine cover you just removed.

You need to remove the tabs holding in the PCV. I used the flat head screwdriver for this. It is easy, but be careful as to not break the tabs.
http://i1253.photobucket.com/albums/hh593/jeenyusz/IMG00290-20120410-1812.jpg

The PCV is held in by two O-rings. One on the inlet just under the clamps you just removed and one on the bottom of the PCV. Both of these can be removed by simply pulling them out. I used WD-40 to help break down any dirt or oil build-up that might have built-up over time.

The picture below will better help illustrate what is holding the bottom of the PCV in place
http://i1253.photobucket.com/albums/hh593/jeenyusz/IMG00291-20120410-1827.jpg

All I did when removing the PCV is spray where the o-rings are with WD-40 and pull till it came out. It did take a little bit of force, but with time it came out.
http://i1253.photobucket.com/albums/hh593/jeenyusz/IMG00292-20120410-1828.jpg

To put the new one in, its just reverse of how you took it out. Put the bottom section in first, make sure it is snug (shouldn't be able to pull it out) and then push in the inlet side. Turn the car on and make sure it is running correctly. If you didn't push it in enough you will get a vacuum leak and essentially the same symptoms you had prior to changing out the PCV.

150.00 never looked soooo plain... New PCV installed.
http://i1253.photobucket.com/albums/hh593/jeenyusz/IMG00293-20120410-1831.jpg

After installed, my car idled better and drove better overall. Enjoy, hope this helps. [wrench]

big_c
05-09-2012, 12:58 PM
Did you notice any oil leaks from the engine due to the defective PCV?

How can one test this PCV?

BTW, great write up, its good to see some info on this finally :)

JEENYUS
05-09-2012, 01:45 PM
Did you notice any oil leaks from the engine due to the defective PCV?

How can one test this PCV?

BTW, great write up, its good to see some info on this finally :)

If you have a bad PCV the symptoms will be your car running like shit. very similar to a bad coilpack. The PCV keeps the your car running smoothly. Due to the bad PCV I now have to replace my valve cover gaskets on both sides. The pressure increase caused from the bad PCV has forced a leak in that area. This is normal.

One thing i forgot to put on the DIY is putting some sort of loob on the new PCV will help with the install.

Around the PCV it might look like there was some sort of leak (in the pictures), but that is just from spraying it with some WD-40. It helped with taking the old one out.

T0M3K
10-10-2012, 09:05 PM
If you have a bad PCV the symptoms will be your car running like shit. very similar to a bad coilpack. The PCV keeps the your car running smoothly. Due to the bad PCV I now have to replace my valve cover gaskets on both sides. The pressure increase caused from the bad PCV has forced a leak in that area. This is normal.

One thing i forgot to put on the DIY is putting some sort of loob on the new PCV will help with the install.

Around the PCV it might look like there was some sort of leak (in the pictures), but that is just from spraying it with some WD-40. It helped with taking the old one out.

I am having horrible leaks through valve covers, wondering if that qualifies as PCV symptom

big_c
12-05-2012, 05:06 PM
Another good modification to do at this same time, is to replace the crappy plastic hoses with 3/4" Heater hoses. Specifically, the two lines closest to the exhaust...right below the throttle body.

I replaced mine a couple days ago, and they crumbled upon removal. Replacing them cured a whistling noise during acceleration. Hoping it keeps my PCV circuit clear and gunk free this winter. Photos are in John Gonzos profile.

imnuts
03-25-2013, 03:02 PM
I plan on replacing my PCV along with the associated hoses that come with the refresh kits available in the coming weeks. Was wondering if you know of a DIY or anything that somewhat shows where the hoses all go. I saw two of them this weekend, but I'm not entirely sure where the other two hoses in the kit go. I'm guessing it'll be fairly obvious once I start to replace them, but I was hoping for some pics ahead of time to be more familiar with what I'd be doing.

T0M3K
03-25-2013, 03:35 PM
I plan on replacing my PCV along with the associated hoses that come with the refresh kits available in the coming weeks. Was wondering if you know of a DIY or anything that somewhat shows where the hoses all go. I saw two of them this weekend, but I'm not entirely sure where the other two hoses in the kit go. I'm guessing it'll be fairly obvious once I start to replace them, but I was hoping for some pics ahead of time to be more familiar with what I'd be doing.

Let me just tell you, take your time, those things are more fragile than they look. My hoses were brittle. Most difficult part is unclipping them, then routing new one.

imnuts
03-25-2013, 05:29 PM
If I can't find pictures, I'll be sure to take some as I'm working on it. I was also planning on getting and installing the intake spacers from JHM at the same time as one of those "while you're in there" things. Was going to set aside an afternoon to work on it, possibly with some friends, so time wouldn't be that much of an issue.

arjun90
06-06-2015, 07:50 AM
Didn't go through >$100+ dollars for the PCV Valve, went with Hudson Parts instead for $40, works great.

imnuts
06-13-2015, 07:25 AM
I swapped out the entire PCV system yesterday. The upper hoses that connect to the valve covers and run to the PCV valve assembly are quite easy, as is the short rubber heater hose one that goes into the rear of the PCV valve. The lower hose thought that goes down into the block is an absolute PITA though. I wanted to get pictures, but my hands and arms were dirty and I didn't have a helper to get pics. I didn't fully remove the throttle body and intake manifold to change out the lower hose, but you need to unbolt the intake manifold at a minimum, unless you have little kid arms/hands.

Shifted_04
08-06-2015, 05:21 PM
Dealing with this currently as well. Found the 90 piece coming from underneath the intake completely clogged. Was chasing my as after oil leaks and now I know why...
18999

Shifted_04
08-06-2015, 08:18 PM
imnuts, when you unbolted the intake tube from the throttle body was there a gasket? Going to be doing this in the morning and replacing breather hose with heater hose since the $ isn't there for the O.E. refresher kit.

imnuts
08-08-2015, 07:50 AM
I believe that there was an o-ring on the connection between the rear intake piping and the throttle body to help seal it, but that is it.

needmovies
10-08-2015, 07:40 AM
I swapped out the entire PCV system yesterday. The upper hoses that connect to the valve covers and run to the PCV valve assembly are quite easy, as is the short rubber heater hose one that goes into the rear of the PCV valve. The lower hose thought that goes down into the block is an absolute PITA though. I wanted to get pictures, but my hands and arms were dirty and I didn't have a helper to get pics. I didn't fully remove the throttle body and intake manifold to change out the lower hose, but you need to unbolt the intake manifold at a minimum, unless you have little kid arms/hands.


which kit did you go with?

I've been getting some leaks from the passenger side valve covers for a while now. I had just replaced the gaskets last saturday, but this morning I got another one of those low oil warning on my way to work. I have not checked yet if I'm leaking again since I was on my way to work.


I have a feeling that my pcv might be clogged. any suggestions if I should just swap out the pancake valve, or if I should do the hoses as well?

cschuster
10-08-2015, 08:11 AM
which kit did you go with?

I've been getting some leaks from the passenger side valve covers for a while now. I had just replaced the gaskets last saturday, but this morning I got another one of those low oil warning on my way to work. I have not checked yet if I'm leaking again since I was on my way to work.


I have a feeling that my pcv might be clogged. any suggestions if I should just swap out the pancake valve, or if I should do the hoses as well?

You may as well just do them all while you're in there - they're going to break anyways, and you can make heater hose replacements for $20ish.

Here's a pretty bad picture, but you can see the heater hose and clamps on the driver side.
http://i1290.photobucket.com/albums/b531/cschuster0/IMG_20150322_193945_zpslyswocfn.jpg

Hose under intake manifold
http://i1290.photobucket.com/albums/b531/cschuster0/IMG_20150321_162404_zpswlxhobbt.jpg

needmovies
10-08-2015, 08:19 AM
You may as well just do them all while you're in there - they're going to break anyways, and you can make heater hose replacements for $20ish.

Here's a pretty bad picture, but you can see the heater hose and clamps on the driver side.
http://i1290.photobucket.com/albums/b531/cschuster0/IMG_20150322_193945_zpslyswocfn.jpg

sorry forgot to mention, I broke the two top hoses back when I did my timing belt two years ago, so I already replaced them with heater hoses. But I did not replace the bottom hose yet.


I was wondering if I should just replace the pancake valve, or get a kit to replace the whole system including the bottom hose that I did not replace before. Or should I get the pancake valve and the bottom hose only, and leave the top two hoses as rubbers?


I am tempted to just replace the valve and leave all the hoses as is seeing how much of a PITA it would be to replace the bottom one. I just wanted to get some opinions to see if the bottom hose gets commonly clogged as well and would need to be replaced.

thanks

SJorge3442
10-08-2015, 08:28 AM
sorry forgot to mention, I broke the two top hoses back when I did my timing belt two years ago, so I already replaced them with heater hoses. But I did not replace the bottom hose yet.


I was wondering if I should just replace the pancake valve, or get a kit to replace the whole system including the bottom hose that I did not replace before. Or should I get the pancake valve and the bottom hose only, and leave the top two hoses as rubbers?


I am tempted to just replace the valve and leave all the hoses as is seeing how much of a PITA it would be to replace the bottom one. I just wanted to get some opinions to see if the bottom hose gets commonly clogged as well and would need to be replaced.

thanks

I would get a new PCV valve and replace the lines with heater hose. No sense replacing them with the crummy, super expensive plastic hoses again. If I remember, I will try to snap some pictures of my lines today after work. Also, the line going under the manifold is likely the brittlest of all the hoses since it is exposed to more heat than any of the other lines.

needmovies
10-12-2015, 10:41 AM
I would get a new PCV valve and replace the lines with heater hose. No sense replacing them with the crummy, super expensive plastic hoses again. If I remember, I will try to snap some pictures of my lines today after work. Also, the line going under the manifold is likely the brittlest of all the hoses since it is exposed to more heat than any of the other lines.


good plan. I went ahead and ordered just the PCV valve. I already replaced the top two lines with heater hose. This weekend I was looking into how to get the bottom one done.

Any thoughts if it's possible to remove/replace without removing the intake manifold? I can see where it attaches to from the side. I definitely can't fit my hand through, but I was thinking, would it be possible to use a long screw driver to unclip the tabs? Once I get the bottom hose off and replaced with the rubber heater hose. I think it'll be stiff enough that I can reattach the tabs by holding onto the upper end of the hose (this is assuming the locking mechanism is similar to the tabs on the top hoses).

SJorge3442
10-12-2015, 10:43 AM
good plan. I went ahead and ordered just the PCV valve. I already replaced the top two lines with heater hose. This weekend I was looking into how to get the bottom one done.

Any thoughts if it's possible to remove/replace without removing the intake manifold? I can see where it attaches to from the side. I definitely can't fit my hand through, but I was thinking, would it be possible to use a long screw driver to unclip the tabs? Once I get the bottom hose off and replaced with the rubber heater hose. I think it'll be stiff enough that I can reattach the tabs by holding onto the upper end of the hose (this is assuming the locking mechanism is similar to the tabs on the top hoses).

The ability to change the lower line WITHOUT removing the manifold is pretty much not possible. To be honest, it would hurt to remove the manifold and replace the gaskets and freshen up the fuel injector o-rings while you're at it. I think it took my 40 minutes total to get the manifold off and I was taking my good old time. The intake manifold gakets cost like $10 from rock auto and the injector o rings are just a few bucks. This would be a prime time to clean the throttle body while you're at it. Just think of it as a huge PM job.

OlivierA4
11-16-2015, 10:54 AM
with 3/4" heater hose what type of fitting I need in order to retrofit and replace the OEM PCV line?

SJorge3442
11-16-2015, 11:13 AM
with 3/4" heater hose what type of fitting I need in order to retrofit and replace the OEM PCV line?

3/4" brass elbows. Like these (http://www.lowes.com/pd_314699-61002-APXE34345PK_0__)

OlivierA4
11-16-2015, 05:34 PM
let me get this straight,
with 3/4" brass elbow insert into heat hose. one end of the brass goes into the original fitting. is this right? the original fitting is then plug back into the engine. I need to get the brass elbow and brass straight fittings right? we can not replace those original fittings that clip back into the engine? these plastic fittings are very scary to pry it off.

Olivier

SJorge3442
11-17-2015, 06:30 AM
let me get this straight,
with 3/4" brass elbow insert into heat hose. one end of the brass goes into the original fitting. is this right? the original fitting is then plug back into the engine. I need to get the brass elbow and brass straight fittings right? we can not replace those original fittings that clip back into the engine? these plastic fittings are very scary to pry it off.

Olivier

Yeah, you need to be careful with those fittings as you're gonna reuse them. All i did to remove the original engine fittings from the cracked hose was I ran a sharp razor blade down the hose where it meets the connection. Cut it so you go through the piping and then the fittings will pull out. You can also use a heat gun to soften the plastic first, but I didn't feel like finding my heat gun that night.

OlivierA4
11-17-2015, 07:52 AM
You can also use a heat gun to soften the plastic first, but I didn't feel like finding my heat gun that night.
Jorge,
thank you for this very bit info. i don't know why i didn't think of heat gun to soften up the plastic.
Olivier

deyrag
11-17-2015, 08:19 AM
If you want a cheap source for the OEM plastic to replace it without looking quite so ghetto this I what i used
http://www.ebay.com/itm/New-Crankcase-Breather-Vent-Hose-Assembly-Fit-Audi-A4-Cabriolet-A6-3-0L-/161317537801?hash=item258f464809

SJorge3442
11-17-2015, 08:35 AM
If you want a cheap source for the OEM plastic to replace it without looking quite so ghetto this I what i used
http://www.ebay.com/itm/New-Crankcase-Breather-Vent-Hose-Assembly-Fit-Audi-A4-Cabriolet-A6-3-0L-/161317537801?hash=item258f464809

not a bad price, but $70 is still a hella lot more than the $20 it took me to fix mine, with a permanent solution. Also, I wouldnt say it looks ghetto as the rear engine cover covers more of the connections and fittings. Do you really go to showing off you 3.0 engine bay? Now if I had a shaved engine bay and a BAT, then maybe I would opt for a more factory looking option [cool]

deyrag
11-17-2015, 02:15 PM
Yes, but it was basically free taking into account the $70 i saved by using an aftermarket pcv valve instead of the OEM one. :)

I just like having things look stock (or better than stock). I even bought a kit of Oetiker clamps to replace all of the hose clamps when I did my engine swap.

duxavant
01-13-2016, 08:58 PM
I realize this thread is getting pretty old but I just bought a 2004 Avant with a 3.0 and I noticed some oil residue collecting on the passenger side valve cover, not too far from where the dipstick is. I'm guessing this indicates some issues with the crankcase breather. The car has 73k on it, no codes and full service records but I'm guessing the lines are caked up. With such low miles, it probably never got warmed up enough to get the gases moving through the lines so everything just settled out and built up. I'm sure whatever lines I touch will turn to dust so I'll need to plan on doing everything but I'm not too familiar with the way the system works. Should I plan on pulling the crankcase breather box off the valley pan and cleaning it out too or will replacing all of the hoses be enough? Is a diaphragm rebuild kit available for the valve like it is for the older models or do I have to replace the valve? I will likely go "ghetto" and use hoses instead of the plastic tubing because I'm not going to the dealer and I find most aftermarket semi-rigid plastic hoses to be short lived.

john_gonzo
01-13-2016, 09:12 PM
Welcome duxavant. Congrats on the purchase.

3/4" ID heater hose with brass fittings and hose clamps works great for this. (EDIT: Image below is okay, but see fitting size info in Post 33 (http://www.audizine.com/forum/showthread.php/480841-DIY-3-0-PCV-Replacement?p=12739835&viewfull=1#post12739835) and a better pic in Post 34 (http://www.audizine.com/forum/showthread.php/480841-DIY-3-0-PCV-Replacement?p=12740117&viewfull=1#post12740117).)


http://www.audizine.com/gallery/data/500/2003_Audi_B6_A4_3-0_PCV_heater_hoses_layout.JPG

http://www.audizine.com/gallery/data/500/2003_Audi_B6_A4_3-0_PCV_heater_hoses_installed.JPG

http://www.audizine.com/gallery/data/500/2003_Audi_B6_A4_3-0_PCV_heater_hoses_installed2.JPG


Also, the valve covers contain baffles that can be snapped out to clean out sludge.

http://www.audizine.com/gallery/data/500/2003_Audi_B6_A4_3-0_drvs_side_valve_cover_and_baffle.jpg

http://www.audizine.com/gallery/data/500/2003_Audi_B6_A4_3-0_pass_side_valve_cover_and_baffle.jpg


The PCV "pancake valve" can be disassembled and cleaned. Probably worth a try as new ones are pricey. I haven't touched the valley pan on mine so I can't offer any feedback about that.

Mikelb01
03-08-2016, 12:01 PM
John_Gonzo: Did you replace all of your PCV hoses with new 3/4" heater type? I think its time for me to do this. I am familiar with the one that connects to the PCV valve itself, but what is the one going next to the firewall?

SJorge3442
03-09-2016, 11:35 AM
John_Gonzo: Did you replace all of your PCV hoses with new 3/4" heater type? I think its time for me to do this. I am familiar with the one that connects to the PCV valve itself, but what is the one going next to the firewall?

Im not sure if John ever replaced the line running to the valley pan, but Im pretty certain all of the hoses were swapped to heater hose. I myself replaced the whole PCV system (including the valley pan hose) with the heater hose. Did this about 7.5K miles ago and things have been running great. With the exception of my PCV clogging due to short drives in the city.

OlivierA4
03-24-2016, 07:33 AM
Im not sure if John ever replaced the line running to the valley pan, but Im pretty certain all of the hoses were swapped to heater hose. I myself replaced the whole PCV system (including the valley pan hose) with the heater hose. Did this about 7.5K miles ago and things have been running great. With the exception of my PCV clogging due to short drives in the city.

Jorge,
thank you for your help in replacing the PCV and heater hose. I put my project on hold until now since winter is pita to work on the driveway. I will do this work very soon (probably 2 weeks if my family time and/or school work allow it) . so sad that I would like to work on the car daily and get it done but ......

vtince
10-20-2017, 01:37 PM
Hey guys, Just an FYI for anyone who is replacing the PCV hoses with heater hose mod. The hose is correct at 3/4" ID. However, if you are getting the 90 degree fittings, make sure its the 1" PEX Fitting. For some reason PEX fittings are not measured by the Inner or Outer diameters. Anyway a 3/4" PEX fitting is only .61" OD so you'll have a pretty noticeable gap between the fitting and the hose.

SO make sure to get 1" PEX fittings for the 3/4" heater hose!!!!!

john_gonzo
10-20-2017, 03:56 PM
vtince, in answer to your PM about elbow quantity, I dug up the pic below. This is the complete PCV system on my 3.0. There are 3 brass elbows total. Hose lengths are written on the carboard. I used heater hose to the valley pan too. I did not remove my intake to install that hose.

I had this whole system out of the car to replace O-rings on the connectors. This is what it looks like after 100,000 miles.

http://www.audizine.com/gallery/data/500/Audi_B6_A4_3-0_PCV_system.JPG