2008 Multivan 2.5 tdi oil leak in air inlet before turbo

[Silver Caravelle]

Gday all,
Lately I have been investigating oil pooling and leaking through black plastic elbow join from air inlet to turbo of the Multivan (128kw tdi)

My mechanic has cleaned it up and is inquiring re new seals for this elbow to stop the oil leak onto the under tray to at least slow down the leak for now and monitor. We discussed whether the turbo is leaking oil into the elbow as the route cause.The engine runs great with no performance issues and I skeptical that the turbo is in need of replacement. Has done 149,000k.

I am now thinking it is excess oil coming out of the PVC into the air inlet tube ( that then joins to the black plastic elbow and pools oil there). I have pulled the PCV hose off and there is a reasonable amount of oil residue, more than just blowby mist.

There is also only oil mist in the intercooler pipe side of the turbo which is a great sign of no oil spewing from the turbo outlet.

If the PCV is knackered letting excess oil to blowby from the rock cover, is there way to test this without accessing the rocker cover? I cannot see that it is straight forward to access this and replace the PCV without major surgery to remove the plastic rocker cover and intake manifold.

Thoughts would be greatly appreciated.

Regards,

Scott

[Greg Roles]

PCV for sure. My turbo is at 267kms and still pretty oil free. Unlikely to leak BACK out the intake, it blows any bearing leak blowby into the intercooler. You'd be wise to fit a Provent 200 catch can in between rocker cover and intake inlet, here's a pic of mine, with a drain hose down to the bottom of the engine with a small plastic irrigation tap at the end for periodic draining. The cheap Provents on eBay are China ones with a basic mesh grid, nowhere near as good as the real deal at about $180, but better than nothing. I run the real thing, and have a China first stage with real Provent second stage on my Yeti, seems to work well.

Ribbed hoses from HKBPerformance on eBay out of SA.

53883

53884

53885

[gregned]

Hi Greg
Thanks for the pics, how and where is the provent attached to the van?

Any pics of the bracelets or how it’s attached?

Cheers

Greg

[Silver Caravelle]

Hi Greg,

Thanks for this and noted re Turbo. I have been checking out whether to go the Provent path as alternative fix. The absolute level of tear down it seems to replace a PCV inside the rocker cover, forces one down the Provent path. The only thing though now, is potentially topping up with oil periodically, given oil still escapes from rocket cover to Provent. Otherwise engine has not needed top ups between each service.

Regards,

Scott

[Greg Roles]

Hi Greg
Thanks for the pics, how and where is the provent attached to the van?

Any pics of the bracelets or how it’s attached?

Cheers

Greg

Zipties to nearby things using the supplied Provent can holder. I'll make it better down the line.

[Greg Roles]

Hi Greg,

Thanks for this and noted re Turbo. I have been checking out whether to go the Provent path as alternative fix. The absolute level of tear down it seems to replace a PCV inside the rocker cover, forces one down the Provent path. The only thing though now, is potentially topping up with oil periodically, given oil still escapes from rocket cover to Provent. Otherwise engine has not needed top ups between each service.

Regards,

Scott

Mate I've never had to top up between changes with a Provent, it's still normal loss, the rocker cover system is hindered by the heat and short route it takes, hence why my Provent is over the other side giving the oil as much time and distance to cool as possible.

[Silver Caravelle]

Cheers Greg. If say the PCV is working correctly as designed, does this ordinarily minimize oil loss from the rocker cover with only prodiminately oily mist blow by? Where as when the PCV is faulty, more oil leaves the rocker cover into the Provent whether the hoses are long or short? Unless there is a good way of recirculating the oil?

Thanks,

Scott

[Greg Roles]

Yes, but the rocker cover PCV is a static "maze", it can't really "wear out" or stop functioning. In your case to stop the pooling it's catch can time. Rocker cover PCV systems work as intended, you add a catch can to stop the overflow the rocker cover still lets through, there is oil blowby "mist" from brand new, it just takes time to coat the intake and start pooling. Your EGR valve area where the engine also adds soot is where the real fun begins. Oil blowby plus soot equals 3D gunk buildup all the way to the cylinders. Problem of modern direct injection cars that don't have a carbie and wash the intake out.

[Silver Caravelle]

Many thanks for the info Greg.
Cheers,
Scott

[Silver Caravelle]

Hi all,

Please see the link below re PCV(s) for the R5 2.5 engine. Attribution to Gnits; Club Tourareg Forum.

It turns out the PCV(s) set up is a little more convoluted and is integrated into the rocker cover with two separate items. On the 2008 T5, it is even more complicated to remove the rocker cover to inspect for perforation of the PVC(s) membranes. If some of these individual membrane parts are not entirely available, then it looks like a complete new plastic rocker cover. What a nightmare.

If these PCVs are working correctly, the oil flow to air inlet duct from blow by should be minimal with predominantly oil mist. If there is a perforation, then oil flow with blow by is likely going increase.

I can see why a Provent is a solution to catch excess oil, but the route cause is still sitting under the rocker cover!

DIY: Touareg 2.5 TDI R5 valve cover PCV valve repair / diaphragm replacement | Club Touareg Forum
DIY: Touareg 2.5 TDI R5 valve cover PCV valve repair / diaphragm replacement | Club Touareg Forum (https://www.clubtouareg.com/threads/diy-touareg-2-5-tdi-r5-valve-cover-pcv-valve-repair-diaphragm-replacement.292643/)

Cheers,

Scott

[Greg Roles]

Do as you wish mate, it's your car, I fit Provent's to every diesel I have ever had, from new, and all my intakes are bone dry, and most important my intake valve stems remain clean! This "oily mist" is the whole problem! If the membrane does indeed eventually fail, I'm still covered. Happy days.

[Silver Caravelle]

Hi Greg,
Sorry I didn't get back to you. Been off line for a bit. As you recommended, I am going to installa Provent 200 or a maybe the Ryco one as it is nearby at Super Cheap with a universal install kit that I might be able to utilize some of the parts.

I have read your threads from some years back and also Transporter's. I am not clear on what you settled to connect the hoses to the PCV hose ends at valve cover and turbo air inlet? To maintain the 45 degree angle join on the turbo air let, 90 degree join at the valve cover end, could cutting the PCV hose off to keep these joins be an option? I did see it mentioned at some point alternatively using copper junctions. Also based on usage over time what type of silicon or rubber pcv hose worked best?

Cheers,

Scott

[Transporter]

Hi Greg,
Sorry I didn't get back to you. Been off line for a bit. As you recommended, I am going to installa Provent 200 or a maybe the Ryco one as it is nearby at Super Cheap with a universal install kit that I might be able to utilize some of the parts.

I have read your threads from some years back and also Transporter's. I am not clear on what you settled to connect the hoses to the PCV hose ends at valve cover and turbo air inlet? To maintain the 45 degree angle join on the turbo air let, 90 degree join at the valve cover end, could cutting the PCV hose off to keep these joins be an option? I did see it mentioned at some point alternatively using copper junctions. Also based on usage over time what type of silicon or rubber pcv hose worked best?

Cheers,

ScottHi mate, ideally you reuse the ends (connectors) or remove 1 connector only, so you void awkward angles to your new hose arrangement to provent kit. Ryco kit is good and for the cartridge maintenance.... I just wash in brake cleaner, dry and reuse. I've done that in my T5 for 140kkm despite I bought 2 spare cartridges. I've used silicon hose, it lasted 11 years and it was like new.

Sent from my SM-N986B using Tapatalk

[Silver Caravelle]

Hi Transporter, thank you very much for clarifying. I will reuse those connectors. Might take a little bit to separate the pcv hose from them in hot water, but yes will sort out the awkward angles for the new hoses. Great tip for the filter too!
Cheers, Scott

[Transporter]

Hi Transporter, thank you very much for clarifying. I will reuse those connectors. Might take a little bit to separate the pcv hose from them in hot water, but yes will sort out the awkward angles for the new hoses. Great tip for the filter too!
Cheers, Scott

Use the heat gun or hairdryer. Works very well.

[Silver Caravelle]

Good day all,
At present, I have not purchased a catch can, as I am still chasing an oil leak and it now does appear a turbo inlet pipe seal was not the culprit. In fact on a positive note there is negligible pcv oil blow by residue either side of the turbo inlet pipe and outlet ( intercooler pipe). The pipe to the intercooler is almost bone dry.

Post some weeks of driving after the engine was decreased is pointing to a leak higher up; and as best as I can view it is likely the rocker cover and less likely the tandem pump gasket.

Any body done a major tear down recently to replace rocker cover and or gasket? Number of hours and approx cost would be useful. This is the version where the intake curls slightly over the rocker cover. There is enough oil dripping down front and more at the back to make for a very oily under tray and oil drips on the driveway.

I think I am over it at present, and my local VW specialist is unable to tackle it due insufficient mechanics at present. So I am going to have track down another specialist ( Melb East).

Regards,

Scott

[Rebuild]

pretty sure you need to remove intake manifold to get to the rocker cover, on a 2.5
If you're mech inclined, here's how to do the manifold,
How to remove Intake Manifold 2.5 174 AXE - The Brick-yard (https://www.brick-yard.co.uk/forum/how-to-remove-intake-manifold-2-5-174-axe_topic77887.html)

Haven't done the rocker myself

[Silver Caravelle]

Hi Steve,
Thank you. Yes unfortunately with VW's crazy design, the rocker cover cannot be removed without major front end surgery as described.

Whilst I am mechanical...to a point, I am not prepared to take on large jobs like this anymore. Many thanks for the link.

Scott

[Silver Caravelle]

Hi all,

I forgot to update your all the outcome of this. It turned out to be turbo gasket oil seal to the head. Amazing where oil leaks travel too!

Resulted in a tear down of turbo and manifold whilst at it and made a call to replace the turbo and have the manifold skimmed to ensure no warping. Hopefully won't have to touch this side of the engine for a long time. Replacing the turbo and skinning the manifold ( and new studs and gaskets) was debatable, but if it did stuff up in the next 50,000 ks or so, it would have effectively involved the same job, so bit of a tough call that one..

Cheers, Scott

[Greg Roles]

Interesting Scott, I've never had a OEM tappet cover system fail, but then I don't normally keep my cars beyond 200thou kms. Yeti PCV system at 300thou still going strong, but yeah no doubt they can fail too.

Glad it got solved, and yeah the T5 turbo gasket setup is easy to get wrong / crush / damage, I wrecked one!!