Increasing Blowby and oil seeping from injector plug

Invig

Active member
Joined
Aug 15, 2021
Location
Adelaide
TDI
Mk5 Jetta BKD
I've owned a Mk5 Jetta BKD (260kkm) for about a year and noticed increasing Blowby from the oil filler. There's also oil seeping from the electrical plug for the injectors, off the side of the head.

What's weird is it doesn't blow smoke, doesn't chew oil, but there's lots of oil in the vapour. 12 months ago the mechanic said compression was fine on all cylinders.

FYI the PVC valve works and I have a catch can installed. Albeit on a long run. Any help?

 

Andyinchville1

Veteran Member
Joined
Apr 7, 2016
Location
Virginia
TDI
2003 Jetta TDI wagon, 5 sp, 226K miles
Hi

I've been reading about catch cans and crankcase pressures and to me it looks like your system has too much restriction which is why your oil filler stick is pushing out.

Restriction is caused by either excessive length of tubing or tubing that is too small and also the fittings that you have as far as the 90s excetera also compound problems as far as restrictions go.

I saw YouTube video where one of the mishimoto oil catch cans had some brass filter in it and that was found to be very restrictive.

While not as elegant , maybe try simply running an elephant hose ( or nose I think some people call it ) and see if your dipstick still pushes out.

If it does not then you know you have too much restriction with your system and will have to find ways to try to reduce the restrictions.

Hope this helps you good luck and let us know how it turns out

I'm particularly interested because I'm looking at either the catch pan or elephant hose mod myself because I am going to be using silicone turbo hoses and silicone hoses don't do well with oil so I need to get the oil out of the system one way or another

Andrew
 

Invig

Active member
Joined
Aug 15, 2021
Location
Adelaide
TDI
Mk5 Jetta BKD
Hi

I've been reading about catch cans and crankcase pressures and to me it looks like your system has too much restriction which is why your oil filler stick is pushing out.
Andrew
Hi Andrew, what's an "oil filler stick"?

If you mean the dipstick, it's not pushing out.

The tubing is quite wide, and shouldn't have too much difficultly venting. You can see the mist coming out the front of the car where it vents.

I'll try removing a join halfway and see if it improves the blowby pressure.

Thanks, Ben
 

Invig

Active member
Joined
Aug 15, 2021
Location
Adelaide
TDI
Mk5 Jetta BKD
I might have overreacted. I changed the oil yesterday and it might have had extra in the tappet cover.

Yet there's still oil seeping out of the electrical connection.

Anyway this is how it looks with the cap rattle.

 
Last edited:

Invig

Active member
Joined
Aug 15, 2021
Location
Adelaide
TDI
Mk5 Jetta BKD
I took your advice on flow and adjusted the catch Can for maximum flow rate, including by drilling holes in the side and removing the valve entirely. I blew down the pipe and it's now very low air resistance. So I'm hoping that the oil seepage will be reduced.
 

jmodge

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Joined
Jun 18, 2015
Location
Greenville, MI
TDI
2001 alh Jetta, RC2 5speed daily commuter and 2000 alh Jetta 5spd swap, 2" lift, hitch, stage 3 TDtuning w/502's backroad cruiser
Not sure if your oil seepage on the electrical plug is external or internal. You may want to put some time into figuring that out. When I worked fleet maintenance our Mack/Volvo trucks had an internal harness oil migration that lunched a couple ecu’s before we caught it. In that case it was an inherent issue and the manufacturer supplied us with harnesses to replace. This story is Just a point of reference, I never owned a PD motor.
 

Invig

Active member
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Aug 15, 2021
Location
Adelaide
TDI
Mk5 Jetta BKD
Thanks, I was relieved to find that oil isn't conductive. And the plug is also a 'port' that takes the injection harness from the camshaft area to the outside, so the oil can only be coming from there.

I also note this isn't something that is mentioned in forums so I think it must be unusual, and therefore likely caused by something I've done that's also unusual. That would be catch Can setup, and it's previously constricted flow leading to high pressure in the top of the engine.

I'll see if lowering that pressure helps, or if I've defeated some seals in the meantime.
 

Invig

Active member
Joined
Aug 15, 2021
Location
Adelaide
TDI
Mk5 Jetta BKD
Not sure if your oil seepage on the electrical plug is external or internal. You may want to put some time into figuring that out. When I worked fleet maintenance our Mack/Volvo trucks had an internal harness oil migration that lunched a couple ecu’s before we caught it. In that case it was an inherent issue and the manufacturer supplied us with harnesses to replace. This story is Just a point of reference, I never owned a PD motor.
Mechanic just suggested injector seals could be gone. The engine runs very well otherwise.
 

Invig

Active member
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Aug 15, 2021
Location
Adelaide
TDI
Mk5 Jetta BKD
Ok thanks for clarifying! Damn.

Just wondering - would you drive the car in this condition, and if so, how long for before it does permanent damage?

It could be my imagination but it seems to be quickly worsening...


Nah it's the valve stems/seals. Engine tear down. Screw that.

Btw it's not blowby but head pressure. My bad.

"What's involved in changing out the Valve stem seals? | TDIClub Forums" https://forums.tdiclub.com/index.ph...-in-changing-out-the-valve-stem-seals.189415/
 

Invig

Active member
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Aug 15, 2021
Location
Adelaide
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Mk5 Jetta BKD
Ok thanks for clarifying! Damn.

Just wondering - would you drive the car in this condition, and if so, how long for before it does permanent damage?

It could be my imagination but it seems to be worsening...

I only drive 2000km/year so it would be great to just ignore it for a while.

Nah it's the valve stems/seals. Engine tear down. Screw that.

Btw it's not blowby but head pressure. My bad.

"What's involved in changing out the Valve stem seals? | TDIClub Forums" https://forums.tdiclub.com/index.ph...-in-changing-out-the-valve-stem-seals.189415/
 

csstevej

Top Post Dawg
Joined
Aug 12, 2004
Location
north nj
TDI
2001 golf tdi 4 door auto now a manual, mine, 2000 golf 2 door M/T son's,daughters 98 NB non-TDI 2.0, 2003 TDI NB for next daughter, head repaired and on road,gluten for punishment got another tdi 2001NB,another yellow tdi NB
Your fine with that….. I don’t see an issue.
 

Invig

Active member
Joined
Aug 15, 2021
Location
Adelaide
TDI
Mk5 Jetta BKD
Your fine with that….. I don’t see an issue.
Thanks - my other concern is it's gotten worse in only a short time (100km). It's now quite difficult to take the oil filler cap while the engine is running, and the amount of oil splatter is higher once it's off.

I'm wondering if the gap in the valve guides is being tunneled out by exhaust gases from the piston?
 

B3achbum

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Jul 7, 2015
Location
North Florida
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(Nigel) 2004 jw GLS 5sp / +332K miles, (Hildegarde) 2008 R320 CDI / +132K miles
One thing which hasn't been mentioned, check the condition of the vacuum supply hose and connection at the back of the vacuum pump.
(, The main one supplying the brake booster and rest of the vacuum lines)

IF you have a leak there, the pump exhausts the air it's pumping down - into the crankcase.
It can add quite a bit of air into the crank, and by necessity at pressure greater than the ambient crankcase pressure.
 

Invig

Active member
Joined
Aug 15, 2021
Location
Adelaide
TDI
Mk5 Jetta BKD
One thing which hasn't been mentioned, check the condition of the vacuum supply hose and connection at the back of the vacuum pump.
(, The main one supplying the brake booster and rest of the vacuum lines)

IF you have a leak there, the pump exhausts the air it's pumping down - into the crankcase.
It can add quite a bit of air into the crank, and by necessity at pressure greater than the ambient crankcase pressure.
That's the rubber hose? Yes it's in good condition at the pump, and elsewhere in the engine bay.

I'm going to take the rocker cover off over the weekend and see if there's any visual evidence of exhaust gases from the chamber escaping. I might see if turning the engine either manually or with the starter shows where gases might be.
 

Invig

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Aug 15, 2021
Location
Adelaide
TDI
Mk5 Jetta BKD
Turns out that it is the CCV valve. I discovered this by starting the engine with the oil filler cap off. The air pressure was reasonable and not putting out visible gases. However when I replaced the oil filler cap and removed again these symptoms had appeared.

I checked the CCV outward flow and it was only working under the high pressure conditions. However when I started the engine with the oil cap off there was no flow from the CCV.

Today I will take off the rocker cover and see if I can cleanup the CCV. Any advice on doing so would be appreciated. I'm guessing that soaking in degreaser would be most effective however I wonder if it won't damage the diaphragm?
 

Invig

Active member
Joined
Aug 15, 2021
Location
Adelaide
TDI
Mk5 Jetta BKD
It turns out that the BKD CCV is a throw-away item (but may be serviceable following this method).

However, I did undertake soaking in degreaser, and then applied a (hand pumped) vacuum to the port. Initially it was stuck, and eventually some chunks came through with the degreaser solution. After a few more cycles, it seemed to move easier. I left to soak for a couple of hours.

When I tried the vacuum again (since you can't apply pressure from the other side) there was no resistance at all. It was working perfectly.

Nevertheless I was worried about the condition of the innards. So I proceeded to crack open the puck. I planned on gluing it back together.

The rubber diaphragm was in great shape, however i wanted to try to get it out to see what was underneath. It wouldn't come out, and in the process I pulled out the plastic cone. Which after cleaning would not go back in.

So the moral of the story is that the BKD CCV can be serviced, using degreaser and hand vacuum pump (for bleeding brakes, $25). If I had my time again, I'd just make sure to rinse well with a hose from the inside, and let dry, then reinstall.

But now I'm buying a new one from VW - not sure what they'll charge given there's no OEM available (or that I could find).

If people want pictures, I can supply.
 

Liverpool-Lad

Member
Joined
Jan 18, 2022
Location
Liverpool
TDI
1.9 AXR
Hi folks, just come across this interesting post as also have a leak from the injector loom my 2006 Polo AXR PD100. It also has a stage 1 remap.

Im wary of just replacing the loom as this could be a symptom rather than the cause, is there a definitive way of checking the CCV valve is all ok (either with the rocker in situ or removing it). Also have a small leak on the turbo - ic pipe at the turbo, have had the pipe replaced but still does it.

Any advice most welcome

Cheers
 

Liverpool-Lad

Member
Joined
Jan 18, 2022
Location
Liverpool
TDI
1.9 AXR
Thanks for the video, still interested how you tested the CCV as I have a feeling I have the same prob possibly. Car has done 99,000 miles
 
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