Leak around Oil filler cap

[Bow]

Evening,

Has anyone had any issues with the oil filler cap leaking? I’ve started to notice that the engine is leaking oil around the cap down into the engine bay.

Is it just a simple swap out for a new cap or is this something more serious?

 

[DXX]

Possibly excessive crankcase pressure from blow-by gases.
How old and what milage?

 

[Bow]

It’s 2017 87k

 

[DXX]

It’s 2017 87k

If it consuming oil? Do you need to top up regularly?

 

[Bow]

Never topped it up in 10 months. Hardly used a drop same goes for the coolant.

 

[DXX]

OK so sounds like serious cylinder / piston ring wear is not the problem.
Obviously check that the rubber seal on the cap is not damaged.
Have a look at this, the Boosted Crankcase Pressure section applies to a T6 (turbocharged)

PCV System Pressure Managment in Turbocharged Applictions

On a naturally aspirated engine,the crankcase pressure is directly related to the piston movement. Turbocharged engines require a more advanced PCV system.

www.knowyourparts.com

Also a video to show what blow-by is, perhaps better videos available

 

[VanDamMan]

One other cause could be Oil/engine pressure regulator fault….there’s a thread link
Regulator valve

 

[Bow]

Great stuff DXX will have a look now. Just panicked when I saw it. Just whacked in a new clutch last week as well

 

[Bow]

Just checked it and attached a few photos not sure how you send a vid but the cap dances round like a goodun when off not loads of smoke out though but it was cold on start up.

 

[DXX]

From the photo it doesn’t look like there is much oil spillage around the filler cap?
Not sure how many miles since your last oil change but see if you can smell Diesel in the engine oil.
Has the fuel economy / performance got worse since the oil leak developed?
Videos need to be uploaded to Youtube first.

 

[DXX]

VW implementation how to eliminate oil from crankcase breather system getting back into air intake:

• Specifically about Transporter EU5 engines on page 13 in VW Self-Study Programme 455: 2.0l TDI engines in the T5 2010, which is available at SSP_455 EDIT: also in the Forum downloads --> SSP 455 - 2.0 Litre TDI Engines in the Volkswagen T5 2010
• More details about the principles in general on pages 18-21 in VW Self-Study Programme 403: 2.0l TDI Engine with Common Rail Fuel Injection System, which is available at SSP_403

 

[RayT6]

Did you find what was causing these problems. I'm having the same issue. Replaced the oil cap but it didn't work.

 

[Bow]

RayT6,

It’s been fine since I cleaned the cap seal and filler neck and refitted