View Full Version : Crankcase Breather Hose

11-30-2006, 08:01 AM
Ok...........I have a large crack in my Crankcase Breather Hose.. The car seems to be running ok.. I know i need to replace it soon but... DOes anyone know the problems that can be caused as a result of this crack and still driving the vehicle...... What would it affect and how..... Any input would be greatly appreciated..


11-30-2006, 08:10 AM
you could try stating what year/engine code your car is

that would help a lot

and maybe which hose is torn

theres more than one

11-30-2006, 08:16 AM
I am thinking he is talking about the most common one of the hose on the valve cover in the back... I have had three tear since owning the car... Most recent one seems to be doing well since it was an upgraded part...

11-30-2006, 08:22 AM
you could try stating what year/engine code your car is

that would help a lot

and maybe which hose is torn

theres more than one


theres is only 1 crankcase breather hose ( larger s shaped hose directly under the intake manifold) coming off the crankcase so uhhh yea man thats the one thats cracked ... as for year its a 98 1.8t quattro.. Idk how thats gonna help ya but yea... so anyone know wut effects it has on the engine...?

11-30-2006, 08:29 AM
Originally posted by NFryan
theres is only 1 crankcase breather hose
if you say so

and neo...aeb's do not have that hose on the back of the valve cover..that is an awm+ thing

11-30-2006, 08:38 AM
crankcase breather hose ( larger s shaped hose directly under the intake manifold) coming off the crankcase

So that hose also from what it looks like connects eventually to the suction pump .. So could this hose if cracked have any bearing on oil pressures ........ Just wondering ....

11-30-2006, 09:02 AM
no bearing on oil pressure

11-30-2006, 09:05 AM
What would it affect... Only thing i really noticed was just stong exhaust smell under the hood. I would imagine it does something negative ....????

11-30-2006, 09:07 AM
it could result in a boost leak

11-30-2006, 09:25 AM
That is apart of the PCV system and will eventually cause a boost leak. I had all sort of issues with my car not holding anything over 7 psi. I replaced every part I could think of and it didn't go away. It ended up being the PCV system.

11-30-2006, 09:33 AM
and you won't be pulling a vacuum on the rings, but if you really need that or not is sort of up in the air, i've been running without any pcv system aside from a catch can without any problems for a while now...

PS: i didn't remove the PCV system in hopes of imporving performance! I removed it because I had no where to put it...lol.

11-30-2006, 11:20 AM
Are there any write-ups on what things to replace on the PCV system? I have an AWM engine and have disconnected the secondary air pump...i'm wondering if I could cause any damage to the PCV system by not having this on? I have a filter on the one end of the crank case breather ever since I put in the Evoms intake.

11-30-2006, 11:33 AM
what does sec air have to do w/ the pcv?

03-15-2007, 05:03 PM
Hi guys, do you have pictures or can you point me to where the breather hose is. I have a 2002 A4 1.8T FWD. Dealer mentioned my breather hose on back of valve cover is brittle and will result in CEL. Thx.

03-15-2007, 05:21 PM
I don't have a picture but it's pretty easy to describe where to look. Open your hood and stare at your engine. As you look up towards the windshield you will see a black connection coming from the back of the engine. If you follow that along it will snake over to the right into all sorts of connections. Just tug on those and you will see if one is damaged. A common place for a crack is when you follow the hose down to the right, there is a long 90 degree angle hose. It's one of the biggest ones.

Unless you are under warrenty this is about one of the easiest things you could replace yourself. Just need a few aligator clamps and a screwdriver.

03-16-2007, 07:03 AM

03-16-2007, 07:19 AM
I think some folks are talking about this one? This is on the back of the AWM motor. I posted about this a couple weeks ago because mine was cracked. You seem to be referring to a different one though.


Here is the link to my thread


03-16-2007, 12:13 PM
I think he's talking about this goofy looking hose. It is a pain to get to. I tried to replace it without removing the intake manifold and it wouldn't budge. Part of the housing it mounts to broke off so the clip wouldn't work anymore. I ended up pulling the intake manifold off to get to it. That is when I decided to build the engine. It was the biggest stretch of the "while you're in there" credo yet.


03-16-2007, 05:48 PM
i just replaced that whole assembly on monday w/o removing the intake manifold. my hand looks like it's been through a meat grinder.

03-16-2007, 05:52 PM
i can get that hose for you. pm me tomorrow and ill price you.

08-28-2008, 05:07 PM
I'll bring this thread back from the dead to ask a question.

Does anyone know where (other than the stealership) I can get the crankcase breather hose that runs under the intake manifold. It has a clip at the bottom right above the oil cooler / bracket and goes up and then back. Mine is literally split in half or seperated from another hose (hard to see down there). ECS has them for AEB / ATW only [confused] I've had a slight boost leak for some time now and this is probably the cause. I can't see onemoremile's picture above anymore but I think it's the hose I need or similar.


ON a side note: What ever happened to b0000sted_Audi ??

08-28-2008, 05:13 PM
What about purems? I know they have alot of parts like that. Plus they have some coupon codes for AZ members in the GB forums.

08-28-2008, 05:53 PM
Checked Purems. Didn't see it. I sent an email / part request to ECS, maybe they can get it for me.

08-28-2008, 06:15 PM
Mine was covered in oil a couple months back. I checked it out, cleaned it up and seems to be fine, I didn't spot any rips/cracks. I wanted to replace it anyway but also had a problem finding the part.. I gave up seeing as how it seems to be fine - but if you find the part, let me know!

08-28-2008, 06:28 PM
The first one listed on this page seems to be it...... not sure if I want to pay that much especially without seeing a picture to make sure first.


or HERE (http://www.statracing.com/oem-replacement/wizard.asp?year=2001&make=AU&model=A4-QT-003&category=B&part=Breather+Hose)

OEQ Breather Hose
2001-2003 Audi A4 QuattroOil Filter Bracket/Housing to Valve Housing.

08-28-2008, 06:54 PM

I think that's everything

08-28-2008, 07:44 PM
The link you posted is for ECS part #5942 which is the one below. If it's the same for AWM I'm all for it but it says ATW & AEB only. [:(]

ECS/OEM Crankcase Breather Hose Kit ES#5942
"S" shaped & "T" shape breather hose kit for crankcase breather, comes with all related harware - ATW & AEB engine codes only learn more

08-28-2008, 07:50 PM
Checked Purems. Didn't see it. I sent an email / part request to ECS, maybe they can get it for me.

Too many parts to put them all on the website. Give them a call.

08-28-2008, 11:56 PM

Second hose down. Don't forget the o-ring that should be replaced at the same time. Also, since you're down there (and it sucks bad, I just did it two weeks ago), might as well replace the rubber t-hose and check valve that it attaches to.

My hose was disintegrating, and had broken apart in three places.

08-29-2008, 05:17 AM
Always a reliable source Autohaus AZ (http://www.autohausaz.com/search/product.aspx?sid=tfa515qslhdufn55vxazc045&makeid=800002@Audi&modelid=1368109@A4%20QUATTRO%20&year=2001&cid=22@Fuel%20%26%20Air%20System&gid=6344@Air%20Intake/Breather%20Hose)

08-29-2008, 11:15 AM
i had the same problem with my hose i just replaced the hose and the t fitting cost like 50 bucks and i did it all in one day

08-29-2008, 01:29 PM
This is the one. Thanks for the AutohausAZ link and everyone's assistance. I ordered it this morning along with a bunch of little things like o-rings, check valves and some other hoses in that area. Looks like I'll be removing the intake manifold because it's a real bitch to get at! [wrench]


#2 on this ETKA diagram for future reference. PArt number written in pen is NOT correct. That is part number for the 3 way hose on back of valve cover that I replaced a few months back.