So I was looking in my throttle body the other day, and its a bit oily/sooty (76k miles).  I'm going to clean it, but this got me thinking about any PCV or EGR system on the car.

 

The breather valve on the rocker cover:

Non-Return Valve Škoda 04E103175 (skoda-parts.com)

 

Which way is this meant to flow?  On mine, I can blow through it into the rocker cover, and feel the air push from the filler cap hole if I put my hand over it.  But when I suck, nothing, the valve is closed.  I initially thought this was a PCV valve designed to extract crankcase fumes into the intake, but its pipe links before the throttle body, so there would never be any inlet vacuum there, and in any case my valve won't allow sucking.  Is it designed to leak makeup air into the rocker cover (in which case my valve only letting air into the head means it is correct?).

 

Diagrams/pictures of the inlet manifold show 3x green seals for the individual runners, and a 4th smaller seal to one side.  Does anyone know what this is for?

   

 

It looks to enter the inlet tract just below the throttle body, which would make it a good position for any EGR or PCV system and therefore a source of oily soot.... or is it for coolant?

 

If I clean and refit the throttle I think I will need to "relearn" it with VCDS, but some people say it self learns if you leave the ignition on first click, any preferences?

 

Cheers,

 

Bread

13 minutes ago, bread82 said:

Is it designed to leak makeup air into the rocker cover (in which case my valve only letting air into the head means it is correct?).

 

Yes, this.

 

Which car and which engine? The linked valve and thread location suggests not the one in your profile.

Edited 12 February, 20233 yr by Breezy_Pete

Sorry, I should have put details; 2013 Citigo, 1.0 mpi CHYA.

In that case I'd think it probably hasn't got an external EGR valve, judging by the lack of any such diagram title here

 https://www.lllparts.co.uk/catalogs/skoda/CZ/CIT/727/1

 

Not sure what that manifold hole is for.

Could be coolant as a way of applying a bit of warmth to the throttle body area above, to prevent potential icing?

Edited 12 February, 20233 yr by Breezy_Pete

Yeah, I noticed that too on ETKA, no mention of EGR. Perhaps it's PCV controlled by the oil separator big plastic plate down on the front of the block, via an internal gallery? The exhaust mani is siamesed inside the block so there could be anything going on in there.

 

Could be coolant, but I just realised there's only one hole so I don't know where it could form a circuit to.

 

I'm gonna take a look into the intake mani when I remove the throttle, in case I can see where the hole comes out.

 

Thanks for your help 🙂