Technical Breather thingy?

[tessiedog]

Hi.
Stilo 1.4 16v 2004. Got a noticeable amount of oil at the top end of the engine, which appears to be coming from what I think is a breather pipe (see photo). Any ideas on cause and cure?
Cheers.

 

[astacheva]

Most likely the PCV (positive crankcase ventilation). It must have a hose connected to the airbox pipes betwen the filter and the thottlebody.

 

[tessiedog]

Thanks for that. Any idea why it might be putting out engine oil and how to cure it?
Cheers.

 

[Artermis]

Thanks for that. Any idea why it might be putting out engine oil and how to cure it?
Cheers.

It's natural behaviour - it's what it's supposed to do.

The engine naturally produces oil vapour as it runs; the crank case ventilation is designed to relieve this pressure so it doesn't build up and blow seals.

Crank cases once upon a time used to just vent to atmosphere, however emissions regulations prevented this and so the vapour is recirculated through the engine intake to be burnt and passed through emissions control devices (i.e. CATs, DPFs).

You can take some basic steps to help your engine and potentially limit the amount of vapour you produce by making sure you run a good quality oil of the correct spec to your engine. Look beyond the simple viscosity rating and think about the oils actual rating, ACEA for euro vehicles I think it is.

Also make sure you don't overfill the oil and adhere to the scheduled changes so you're running good clean oil.

 

[tessiedog]

Hi again
Closer inspection looks like what is in fact only a small amount of oil coming from this (rather than the breather as I had previously thought). Any ideas?
Cheers and tia.

 

[Ralf S.]

I presume that in the first photo there is a rubber hose attached over the hole and that it's not just left open to the atmosphere..?

Are you really, really sure the leak is not from this hose? Stick some Blue Hylomar or gasket goo over the metal stub and then re-attach the hose and clip. If the clip is a Klik clip then chances are that it's become stretched over time... (if you buy a new one, you'll be amazed at the difference) coupled with a hardened, slightly expanded hose, it's a prime candidate for a leak.

The oil could also be seeping out from that sensor next to the plug.

The button next to it looks like a blanking plug for a sensor of some sort (possibly for a different version of the sensor you have next to it) or it's for some tool access used during the engine manufacture.

Anyways, if it has a hex head you can unscrew it, clean up the threads and stick some gasket goo in there to re-seal it. If it's just a round hole in the top, then it's more tricksy.. but then these tend to be "sealed" and don't ever leak... which is why I think the mess is coming from the hose, or possibly the sensor.

Ralf S.

 

[tessiedog]

Hi Ralf S
Thanks for that, I'll give these things a go.
Cheers