I own a 04 Fabia hatchback, 1,4 liter 16v. 

 

Firstly, I searched hi and low for an answer to my enquiry, but was unable to find a satisfactory one.

 

So this is the story :

 

My CEL went on one day, took it to mechanic, he told me I had an  egr valve fault - the valve needed a cleaning. He cleared the error, and the light did not come back on. The car also made a kinda 'tic-tic-tic' sound when starting cold, and when I gave it just a little bit of throttle. Mechanic said this was related to the egr valve fault, in that the valve needed a cleaning and therefor made the ticking sound. Few months later CEL came on again, this time I cleared it my self, and decided to try and clean the egr valve. I cleaned out the sucker with 'succes'. CEL isn't back on, but the ticking sound is still there. When I took off the egr valve to clean it, the guides I read all mention a hose that one needs to disconnect in order to get the valve out. I found no such hose. It is clear on the valve, where the hose is supposed to be (see picture) , but there is no hose connected. I looked for any loose hose, but didn't not find any. So basically I just cleaned out the valve best I could and put it back on there. My question is regarding this lack of hose, (see picture) what is its function? Is it important and do I need to fit a new one on? 

 

Hope this make sense, thanks for reading.

 

 

Torbjorn 

You have everything there that is supposed to be there. The short length of rubber hose ends in a very basic air filter (the black and white plastic cylinder, I haven't opened one up, so I don't know what it looks like inside, probably a labyrinth of passageways to make it hard for particulates to get through).

 

The following is my best attempt at explaining why a filtered air supply is needed, based on cutting up a (1.2/12-valve) one and looking at it, rather than any education:-

 

There's no water cooling on these EGRs, so the valve stem probably will be very hot, maybe hotter than a rubber seal could survive. So there isn't a rubber seal, or any other gas-tight seal between the valve stem and the valve guide.  Whenever the EGR valve is open, there will be lower than ambient pressure in the inlet manifold; and that is connected to the EGR by the steel pipe, so the pressure in the EGR valve will also be lower than atmospheric.  So any gasflow in the clearance between the valve guide and the valve stem will be inwards, from the ambient air in the engine bay.  To reduce the amount of particulate debris that might contaminate the valve guide/stem, filtered air is allowed in through the basic filter and short hose in your photos.  It may be that this inevitable small airflow also serves a cooling function for the valve stem on the way in.

On some variants (e.g. 1.2 12-valve engine) the hose is connected to the engine's air filter (clean side) instead of the plastic thing; this is possibly where you've seen reference to disconnecting a hose? 

 

Did you find the EGR valve very dirty when you've cleaned it?  Usually, the dirty area is at the far end of the steel pipe, where it connects into the inlet manifold. At that point it meets up with oil mist from the PCV system and tends to condense tarry crap in and around the end of its outlet.  There's a 'how to' guide in the Fabia guides section about cleaning this end of the pipe on an AUB code engine.  What's your engine code?

 

 

Thank you for the highly detailed response! 

 

I accidentally deleted the fault codes, before writing them down. Brilliance at work. I will not make that mistake twice. 

 

The valve didn't seem very dirty at all, there was some soot, but not a lot. I scraped some of it out (only at the inlet and outlet, made sure not to poke into it), and use egr valve cleaner. Bear in mind I haven't seen many, so it's based on very limited experience. I'll attach some photos, hard to tell from them though. 

 

I did not check the far end of the long metal pipe. Should I take it apart again and have another look? I'm thinking that waiting to see if the CEL comes back on may be the way to go, or is that wishful thinking? 

 

Thanks! 

On these (petrol engined) cars the EGR valve itself is very hot, so it tends to be self-cleaning, as any soot deposited will just burn away during hotter running conditions. It may even be that the air (oxygen part) coming through that crude/simple plastic filter is there to help with this! (I've just thought). I think removing the throttle body will give you enough visual/manual access to see if the far end of the EGR pipe is clogged. Have a look here https://www.briskoda.net/forums/topic/357611-14-16v-aub-egr-service/, but if your engine code is BBY or BBZ it may be easier than what you see there.

Why does that plastic filter thingy look like a non-return valve then? I thought it was to allow pressure equalisation so that the pintle can't be lifted by positive pressure pulses on the inlet side.

9 hours ago, sepulchrave said:

Why does that plastic filter thingy look like a non-return valve then?

Dunno, but it isn't one.  037133843A, described in the parts catalogue as " air filter" , and I can blow or suck either way through mine. 

Working on getting mine apart (non-destructively) to examine the innards, but it's putting up a bit of a fight so far.

 

Can't see pressure pulses being able to get enough purchase on the valve head to move it, the cross-sectional area they'd be acting on is tiny.

 

Hehe, it is a tiny little proper filter, a fine metal gauze in the black bit, and a disc of foam filter in between the black and greyish bit:

 

 

Edited 7 September, 20178 yr by Wino
Added info/pic