# 02 Eurovan question-causes of engine oil in the airbox?



## Passat514 (Apr 1, 2005)

Hi all,
Looked at an '02 EV today and found engine oil in the airbox-a good amount of it too.
Van only has 86k on it.
Possible causes?
Bad PCV system?
"Blow by"? (never heard of this as an issue on a VR6 before)
They are hard to come by these days, but is this one worth it if a good deal can be had?
Thanks all!


----------



## enordrum (Sep 23, 2001)

*Re: 02 Eurovan question-causes of engine oil in the airbox? (Passat514)*


_Quote, originally posted by *Passat514* »_
Possible causes?
Bad PCV system?
"Blow by"? (never heard of this as an issue on a VR6 before)


That's what I would guess.


----------



## Passat514 (Apr 1, 2005)

*Re: 02 Eurovan question-causes of engine oil in the airbox? (enordrum)*

dealer found that the oil had been badly overfilled. Is in process of fixing that plus new MAF / cleanup the intake tract due to oil contaminating it. Will be checking it out again after repairs...


----------



## vwbugstuff (Mar 27, 2004)

*Re: 02 Eurovan question-causes of engine oil in the airbox? (Passat514)*

Our '03 has been doing this for awhile and the crankcase has never been overfilled.

Here is my original post:
http://forums.vwvortex.com/zerothread?id=4044119
No definitive answers, unfortunately.










_Modified by vwbugstuff at 10:52 PM 5-27-2009_


----------



## VW_Enthu1 (Oct 23, 2004)

*Re: 02 Eurovan question-causes of engine oil in the airbox? (vwbugstuff)*

Mine did this too - it was the valve assembly...


----------



## vwbugstuff (Mar 27, 2004)

*Re: 02 Eurovan question-causes of engine oil in the airbox? (VW_Enthu1)*

Mark,
I'm assuming you replaced the PCV? How much did you end up paying and where?


----------



## VW_Enthu1 (Oct 23, 2004)

*Re: 02 Eurovan question-causes of engine oil in the airbox? (vwbugstuff)*

Go here. He'll set you up. Good guy....tell him your problem...share with him...
http://store.europarts-sd.com/...age=1


----------



## Passat514 (Apr 1, 2005)

*Re: 02 Eurovan question-causes of engine oil in the airbox? (vwbugstuff)*

I don't see a PCV valve listed for the EV at 1stVWParts.com. Does the combi valve handle the function?
What's interesting is that my Bentley repair manual says there's one.


----------



## vwbugstuff (Mar 27, 2004)

*Re: 02 Eurovan question-causes of engine oil in the airbox? (Passat514)*

http://store.europarts-sd.com/...=2953
Price has dropped considerably. I might have to order from them. Do you have the OEM part number for comparison?


----------



## Passat514 (Apr 1, 2005)

*Re: 02 Eurovan question-causes of engine oil in the airbox? (VW_Enthu1)*

Mark,
Did you get enough oil into the air filter/airbox for it to drip out of the airbox after extended highway driving (consistant 70mph)? 
We just drove the van and made it 60 miles before the van started "bucking" , EPC and ASR/Traction control warning lights illuminated again. 
Stopped at a truckstop and more oil draining onto the ground (about 1/2 to 1 cup of oil)


----------



## VW_Enthu1 (Oct 23, 2004)

*Re: 02 Eurovan question-causes of engine oil in the airbox? (Passat514)*

Uh oh. No, not that much. I just had a coating. That needs to be peeked at...


----------



## Passat514 (Apr 1, 2005)

*Re: 02 Eurovan question-causes of engine oil in the airbox? (VW_Enthu1)*

That's my fear. I did some browsing via Google and it's said that a bad pcv valve can cause oil deposit into the air filter as well as oil into the intake tract. 
I wonder that the valve is not functioning as it should, causing this much oil to flow into the intake tube and down into the airbox? 
What else could cause this much oil to flow into the airbox? It could only be coming from the Crankcase Breather, right?


----------



## duncan1 (Dec 11, 2005)

*Re: 02 Eurovan question-causes of engine oil in the airbox? (Passat514)*

I just found out that our van too has the same issue but it is just a fine residue in the intake with some drop on filter element. I called my trusty dealership and they think its is the PCV.


----------



## Passat514 (Apr 1, 2005)

*Re: 02 Eurovan question-causes of engine oil in the airbox? (duncan1)*

OK, disconnected the crankcase breather tube from the valve cover and the intake. It's not blocked in any way. There's no "PCV" valve per se in this crankcase breather tube and there's no valve that I could see in the valve cover where the breather tube connects. Is that how it's supposed to be?? 
What regulates the amount of crankcase vapors being introduced to the intake air stream on this engine?? Shouldn't there be a vacuum operated/controlled valve of some sort?


----------



## Passat514 (Apr 1, 2005)

*Re: 02 Eurovan question-causes of engine oil in the airbox? (Passat514)*

Problem solved...
Disconnected the Crankcase ventilation tube from the valve cover and the intake pipe. Disconnected the small vacuum hose that runs parallel to the ventilation tube from it's own vacuum port on the end of the valve cover, just below where the check valve plugs in and just above where the intake valve control is located. 
Vacuum tube was almost completely plugged and the 90 degree elbow that the vacuum hose connects to on the larger crankcase ventilation hose was also plugged/gummed up with tar. 
Took the 90 degree elbow off, cleaned it out, cleaned out the orifice that the elbow connects to on the breather hose, replaced the 10 inches of vacuum tube and a couple of fresh O rings on either end of the breather hose assembly.
NO MORE OIL in the airbox!!!!! 
Plus, I saved the $110 for the new crankcase ventilation assembly (www.europarts-sd.com had the best price I could find, plus Steve's a class act there) 
Thanks to all for their advice, knowledge and wisdom!


----------



## Passat514 (Apr 1, 2005)

*Re: 02 Eurovan question-causes of engine oil in the airbox? (Passat514)*

Followup:
There is another vacuum line that connects to the intake just opposite of the crankcase breather. It runs down in front of the engine to the lower right corner of the valve cover, just behind the radiator.
When dismantling the intake and crankcase breather assembly, I also disconnected the "front" side vacuum connection. This seems to be where the oil was entering the intake, which then ran down the intake tube and filled up the air cleaner with oil.
The plugged vacuum line for the crankcase ventilation hose must have been causing it to not allow enough vapors/crankcase pressure to vent into the intake. This would have raised the pressure inside the engine, causing oil to push up the "frontside" vacuum hose and into the intake.
Also checked compression on the engine (prior to taking everything apart) to make sure it was worth the effort. 155 to 163 psi accross all cylinders (5 of the 6 are within 3 lbs of eachother and #4 is at 163lbs). Converting PSI to BAR, all cylinders are 10.7 BAR or higher.
VW spec, per Bentley CD Rom is 10 to 13 BAR for a NEW engine and a wear limit of 7.5 BAR (109 psi) with no more than 3 BAR of difference between cylinders.
Not bad for a motor with 86k on it and questionable maintenance (lots of tar/gunk inside the valve cover)


----------



## rensho (Jan 21, 2002)

That thin 1/4" front line should be the air shroud for the injectors.


----------



## vwbugstuff (Mar 27, 2004)

*Re: 02 Eurovan question-causes of engine oil in the airbox? (Passat514)*

Passat514,
Could you post some pictures of the hose and the elbow and the location of each please?
Thanks!!!


----------



## Passat514 (Apr 1, 2005)

*Re: 02 Eurovan question-causes of engine oil in the airbox? (vwbugstuff)*

Sure.
Here's a closeup of the breather hose where it connects to the intake. It's at the top of the picture, on the firewall side of the intake. You can see the white 90 degree elbow with the vacuum line attached.








Here's a pic of the entire crankcase ventilation/PCV assembly, courtesey of http://www.europarts-sd.com. They sell the whole unit for $110. My dealer was $160.








Good luck!


----------



## phenob (Jun 7, 2009)

*Re: 02 Eurovan question-causes of engine oil in the airbox? (Passat514)*


_Quote, originally posted by *Passat514* »_
The plugged vacuum line for the crankcase ventilation hose must have been causing it to not allow enough vapors/crankcase pressure to vent into the intake. This would have raised the pressure inside the engine, causing oil to push up the "frontside" vacuum hose and into the intake.

Excellent write up. This is exactly what I found today. Always wondered where that oil on the belly pan was coming from.
That small vacuum line along the PCV hose crumbled almost instantly when I yanked it. Should be no problem to replace with regular old 2mm.
Edit: 4mm hose did the trick.


_Modified by phenob at 8:40 PM 6-7-2009_


----------



## duncan1 (Dec 11, 2005)

*Re: 02 Eurovan question-causes of engine oil in the airbox? (Passat514)*

I did exactly what you did: remove the big breather hose with the little hose but they were in good shape and not plugged at all. I wiped out the air intake a week ago and have NO new oil in the intake.... I just wish I knew what made it stop.... What really bothers me is the price of $110.00 for a foot of plastic tubing. Wow.


----------



## troverman (Aug 30, 2005)

*Re: 02 Eurovan question-causes of engine oil in the airbox? (duncan1)*

The question is, does this oil ruin the MAF?
I have check engine on, code P0171 (too lean condition). I have oil in the intake pipe, a considerable amount. Some has leaked back to the MAF. 
I will check the vac. lines and try to clean it all out tonight.


----------



## enordrum (Sep 23, 2001)

*Re: 02 Eurovan question-causes of engine oil in the airbox? (troverman)*


_Quote, originally posted by *troverman* »_The question is, does this oil ruin the MAF?
I have check engine on, code P0171 (too lean condition). I have oil in the intake pipe, a considerable amount. Some has leaked back to the MAF. 
I will check the vac. lines and try to clean it all out tonight. 

Too lean usually means an air leak between the MAF and the engine. Usually a cracked hose, sometimes leaking manifold gasket.


----------



## Passat514 (Apr 1, 2005)

*Re: 02 Eurovan question-causes of engine oil in the airbox? (troverman)*

Check all of the fittings along the intake tube that connects the airbox/MAF to the throttle body. 
Our van's check engine light came on this weekend (not a happy moment for my wife, considering all that we've been through with this van). Same code(s) you had: Bank 1, too lean, Bank 2, too lean. Accelaration was noticably slower as well.
Took a look and the heating element for the Crankcase vent tube (the same one that's in the pics in the previous posts) had snapped off of the air intake tube. 
Nice, I thought. VW just glues the f'n thing on and expects it to last? 
So, some epoxy and a couple of zip ties around the base of the heating element and the "oxbow" in the intake tube to keep it from ever disconnecting again and we are back in business.
As to the question of the oil contaminating the MAF: yes it will. If there's enough oil that you see it has soaked into the air filter, your MAF will likely be getting coated with oil. Get some MAF sensor cleaner spray and clean off the element (do a search on how to clean a MAF).


----------



## troverman (Aug 30, 2005)

*Re: 02 Eurovan question-causes of engine oil in the airbox? (Passat514)*

Well I checked it all out last night. Even though on Saturday I cleaned the intake tube, there was fresh oil in the pipe last night. There is none in the airbox, though. There is enough oil in the intake pipe that it will drip out of the end. The PCV pipe is clear, and I can stick my finger into the port on the valve cover where it connects. There are some deposits around the inner edges of the valve cover port, but not too much and I didn't want to push them into the valve cover so they stay for now. The small vacuum line that connects to the PCV plastic pipe is clear, as are the connections into the pipe and into the valve cover. 
What do the two electrical connections on the PCV plastic pipe do? (One is the plug right at the end where the tube connects to the intake pipe; the other is smaller at the vacuum line in)
I cleared the MIL and it hasn't come back on yet, but I bet it will. I poured rubbing alcohol over the MAF sensor and diode in an effort to clean it. The van seems to run fine. My last theory is to check the secondary air injection valve and see if it is stuck open, causing unmetered air to exist at the oxygen system, making the van think the system is running lean?


----------



## Passat514 (Apr 1, 2005)

*Re: 02 Eurovan question-causes of engine oil in the airbox? (troverman)*

The top electrical connection on the PCV tube where it connects to the intake pipe is for the heating element. I don't recall a second electrical connection on the PCV tube or vacuum line that runs along with it. 
Our van is an '02.


----------



## troverman (Aug 30, 2005)

*Re: 02 Eurovan question-causes of engine oil in the airbox? (Passat514)*

You are right--the other connection is nearby but goes to something else. What does the heating element do? I mean, what needs to be heated? 
As for P0171--I took the belly pan off and checked the lower vacuum lines--everything seems fine, but the large plastic hose that goes from the intake up top down to the lowest point of the manifold was loosely inserted at the bottom. Not to the point where it would leak (I think) but loose. I reinserted it and it seems tighter now. 
I thought maybe the SAI valve was stuck open, allowing unmetered air to flow across the o2 sensor, but I could not blow through the tube that comes off the SAI pump with the engine off, so apparently the valve is shut. 
Maybe its the MAF after all? Could a bad o2 sensor cause this? I think they have a life of about 80k? The EV has 98k now.


----------



## phenob (Jun 7, 2009)

Note the bentley does not even think about looking at an O2 sensor for P0171. Vacuum leak as described above is the common cause, and replacing the MAF is the final solution. It also notes a look at the fuel pump. Have also heard a bad evap valve can do this. Replacing maf and evap later today, will update asap. 
In my case, there was not too much oil at 100k. Throttle body looked like maybe 40k, very clean. No oil on air filter. Still looking for better than pep boys vacuum hose. 4mm works but could be tighter. Also that PCV line is surprisingly noisy without braid. Maybe that's where your $110 goes.

_Modified by phenob at 10:16 AM 6-24-2009_


_Modified by phenob at 10:19 AM 6-24-2009_


----------



## troverman (Aug 30, 2005)

*Re: (phenob)*

I am probably going to suck up the $200 for a new VW MAF and hope that cures the problem. That will be in addition to $300 worth of VW front brakes, and $1000 for a new suspension compressor for the Land Rover which recently failed.


----------



## phenob (Jun 7, 2009)

europarts has the VW MAF for $150. The evap valve was $100.
Found more oil on the old MAF and in the tube than when I first cleaned it out. Now that air can get through the breather tube I suppose it's blowing around what oil is left. There was oil on the MAF housing now where there was none before. Cleaned it again, replaced MAF and evap valve, replaced all the little vacuum tubes. No codes after 40 miles. Was previously throwing fuel trim lean code religiously at around 8 miles. We'll see.


----------



## troverman (Aug 30, 2005)

*Re: (phenob)*

Did you just go ahead and change both the MAF and evap sensor? Or one at a time to try and see which one? 
I think we're going to do the MAF, it is $190 + we can get 10% off, and the dealer has it in stock.


----------



## phenob (Jun 7, 2009)

I changed them both outright, although had there been more time for this, i'd have gone slowly to see what made the difference.
From what i can tell, my maf went to hell after taking a jumpstart. The evap valve was known bad/going out for months, as it will make a horrible clicking sound when it starts to go. sounds like valves tapping, can't miss it.
100ish miles now, no codes. Will take the intake apart again tomorrow and re-check for oil.
http://store.europarts-sd.com/...=2162
$145 MAF - Arrived OEM Bosch as indicated. Europarts rules.


----------



## troverman (Aug 30, 2005)

*Re: (phenob)*

Glad yours seems to be fixed. We're not getting any unusual clicking, so it probably is just the MAF. EPC and ESP warnings are on now, too. Its running fine, but I expect these will go away with the next restart.


----------



## CHETVW007 (Jul 25, 2001)

*Re: (troverman)*

Great write up. Super detailed...thanks guys!


----------



## troverman (Aug 30, 2005)

*Re: (CHETVW007)*

Replaced the MAF with new one from VW. It has gone 120 mi, no codes. Still some oil in the intake tube.


----------



## phenob (Jun 7, 2009)

Road trip from Los Angeles to Sedona, AZ, almost exactly 1k miles, no codes. Running like a total champ.


----------



## chendermi (May 20, 2004)

*Re: (phenob)*

Well, except for the brakes.









_Quote, originally posted by *phenob* »_Road trip from Los Angeles to Sedona, AZ, almost exactly 1k miles, no codes. Running like a total champ.


----------



## rensho (Jan 21, 2002)

I just changed out to a new MAF. The throttle is so smoooooooth now. I would not have said the old throttle was not smooth, but with the new MAF, it is noticeably smoother.
I'm hoping for a mileage bump too.







Have been getting 18.0mpg combined, driving very easily.


----------



## Jalendragon (Dec 1, 2012)

I'm a little worried about this now. I have a very fine sheen of oil on my intake, and lots of crud on the valve. However, there was only a little oil on the air filter (looked more like oily fingerprints) and no visible sheen of oil on the air filter side of the assembly. It was all on the intake side of the hose. 

I'd be taking the thing apart again, but now I have a freezing and below weekend coming up.


----------



## Passat514 (Apr 1, 2005)

A light "sheen" / coating of oil in the intake tube, downhill from where the crankcase vent hose connects to the air intake tube is not uncommon-especially in colder temps where the crankcase vent will be carrying a lot of condensation/moisture out of the crankcase as the engine heats up.

My severe "puking" of oil out of the crankcase vent hose and into the air intake, down to the airbox/fouling the air filter and draining out the bottom turned out to be caused by sever sludge buildup on the valvetrain that blocked lubricating oil from the valvetrain aread from draining back down into the block. The backed up oil would get sucked into the crankcase vent chamber and up the crankcase vent hose, into the air intake. 

The crankcase vent chamber/oil separator is inside the raised section of the valve cover on the left end of the head where the crankcase vent hose connects. It uses stainless steel wool inside that chamber to separate the oil droplets from the air/water vapor being sucked out of the crankcase. In the case of our engine, the entire chamber/steel wool was solidly caked with sludge, so that there was no separation of oil from the air possible. 

Removing the valve cover and manually cleaning the vent mechanism/stainless mesh of the sludge buildup as well as cleaning all of the sludge from the valvetrain area completely resolved the issue of oil buildup in the air intake tube/air cleaner.

Your problem could be due to the crankcase vent filter/mesh being less efficient at separating the oil out of the crankcase vent gasses


----------



## FreeMovin (Aug 4, 2016)

Hello,

Thanks for the description and help on this problem. Several months ago, also facing with oil in the airbox I proceeded in changing the Crankcase/PCV Valve with this new piece (http://europarts-sd.com/crankcasepcvbreatherhoseassembly2001-2003.asp) as I have a Eurovan 2002.
Last week, after fixing a windshield wiper reservoir leak, I had to take the MAF out and noticed there was still some oil in the airbox.:banghead:
I noticed Passat514 mentioned that it's not uncommon in colder temps and as I have moved to Colorado it's pretty cold these days. Anyone have an idea on where the problem could be ?

Thanks
Frederic


----------



## masta shake (Apr 19, 2016)

*P1151*

I have this condition of oil in the throttle tube but a P1151 code in my 03. I recently replaced some vacuum hoses along with my brake booster. While looking under the hood today prior to cleaning the mass airflow unit I looked at those hoses. A couple of them seemed to be a little squished. I'm wondering if the vacuum hoses I used arent stiff enough to hold the pressure. I'm going to do the checking over of the PCV hose and all the associated Lions there too. It's possible that I have a clog. I'll let you know what I find. I also have a P0420 and a P0507 that just popped up. I don't think they're related.

My catalytic converter has a little crack in it that I'm going to try and seal up. These vans are interesting. This one is a Weekender has 227,000 miles. I've put about 10,000 miles on it since I got it. Ive done a rebuilt motor purchased from VW and installed by a local shop, and rebuilt transmission done locally. Once I can round up all these little problems it should be a solid van.


----------



## robinson1509 (Nov 25, 2009)

I would guess the P0420 is a symptom and not the cause. Check the diaphragm in the secondary air and also in the pcv. The diaphragm may have ruptured causing a vacuum leak increasing the idle (p0507) allowing air and oil to be pulled in from the block causing the p0420. Just unplug the flexible hose going into the air box and blow in it. If the kombi valve is good you shouldn't be able to blow through the pipe. Just my guess easy enough to check.

Sent from my SPH-L900 using Tapatalk


----------

