I've read that sometimes when your Skoda is consumming a lot of oil then the crankcase breather system needs a clean.  I've got a 1.4 2002 Fabia Comfort 16v.  Could anybody here give some advice on how to clean the above.....and hopefully not be too techincal.? Thank you.

Well, my experience is, with the BBY 1.4 16v 75PS engine, that something starts to go wrong within the air/oil separator - and  I don't think that you can take it apart - it is made to have no serviceable parts. I took a big risk and just ordered in a new one, though I did consider that it would cost quite a big of money as it has a motor fitted into it. In the event it cost £80>90 from VAG, but the oil usage has dropped dramatically in the roughly 4 months since I fitted it. It has been said that it is this oil usage that can lead to pinking, but I am still running the "super fuel" from Shell in it as that did halt the pinking and made that car a lot more lively - which means a lot with the BBY engine. Sometime I will probably open up the old air/oil separator and see if I can work out what has/can go wrong - maybe it is as simple as the wall surfaces of the vortex area getting fouled up - or the motor not working as intended.  That air/oil separator is secured with 3-off bolts and they are a bit challenging to reach - but very do-able - which is handy as my daughter's late 2009 Ibiza SC 1.4 16v 85PS is spraying oil out on to its inlet manifold and it seems that this is due to the air/oil separator seal(s) failing, so that will be job for the spring!

I would think that that task is beyond me run4mo but thanks for posting it.  But I have seen a couple of people mention that the crankcase breather system should be cleaned.  It can't do any harm to do this.  Any advice on how to do it?

The trouble is, the older simple oil/air seperators were reasonably easy to wash out, but this new one, if that is what is fitted to your car (is the engine a BBY 75PS one?), is quite big and full of "unknown/unseen" voids - so you would never to able to see what/where is clogged up and if you had cleaned it. All you can do is clean up any interconnecting pipes and restrictor/one way valves if your engine has any fitted. From memory, there is an "input" which is a large hole in the top of the engine, the oil drop out point which is a smaller hole near the bottom of the engine, and the purging point which takes the waste gases into the engine induction tract. So that only leaves the purging point pipework etc to clean up. As I've said already, apart from being a bit tricky to reach the fixing bolts, it is easy enough to remove - being tall and flexible does help as you end up leaning on/over the engine and working blind with your hand taking out one bolt at a time. Remember that I said that this assembly, if same as my one, has a flap control motor fitted into it, I'd guess to throttle the flow of purging gases during periods of high vacumm - which was an issue with older cars as if this was not done, then the engine would run too lean or stall - these newer engines tend to have a MAP sensor closer to the throttle body so they don't care where their incoming air is coming from and so will continue to happily run with too much purging which might lead to them drinking too much oil - just my thoughts that is all. 

I'd like to quote what somebody said in another thread:

 

The crankcase breather system is a rubber hose that comes from the back of the block (behind the dipstick area) and connects to the side of the air filter. There is then an internal pipe that runs the length of the air filter, open at the throttle body end, rubber mushroom vavlve at the other. Often there are generous deposits of mayo in the pipe whcih need cleaning out with carb cleaner or solvent. I do mine every 5000 miles with an oil change, if it starts to block you will notice increased oil consumption. I havealso used engine flush a couple of times, but I've done 85k miles. A search will throw up plenty on both problems.

 

 

I've been looking down that 'internal pipe, and there is a solid membrane at the rubber hose end.  Am I correct in saying that this shouldn't be there?

I'd like to quote what somebody said in another thread:

 

 

I've been looking down that 'internal pipe, and there is a solid membrane at the rubber hose end.  Am I correct in saying that this shouldn't be there?

 

Can you work out which engine is fitted into your car ie BBY or A?? I will have a look at my ETOS parts catalogue wheh I get home. I'd suspect most of the talk about cleaning these systems relates to the older 8V engines - but I could be wrong.

I'm sorry but I'm not sure how to find out whether it's a BBY or A.  I've tried searching on the web but no joy.

This is the thread I've just found:

 

http://www.briskoda.net/forums/topic/154743-14-16v-crankcase-breather-system-where-is-it/?hl=%2Bclean+%2Bcrankcase+%2Bbreather+%2Bsystem#entry1951301

SWMBO had, latterly, a BMW E46 320d mSport.

The crankcase breather was, as with your car, a pain, to get the bolts out of, but, and bearing in mind this was a BMW maintained car, am I glad it was changed..... Gunge and goo sums it up, and that's with proper oil etc.

If you can't do it, then take it to a local trusted garage (my local did it for £40, including removal, cleaning, and refitting of the egr valve)

I've found out the name of this pipe; it's called the 'Vent hose'.  Does anybody know if the partial blocking of it the rubber pipe attachment end is of importance?  There was a kind of membrane in there and I thought it was solidifed gunk.  I'm worried that this maybe not the case as I poked a hole in it.  How will this effect the running of the car?  Anybody know?

I've found out the name of this pipe; it's called the 'Vent hose'.  Does anybody know if the partial blocking of it the rubber pipe attachment end is of importance?  There was a kind of membrane in there and I thought it was solidifed gunk.  I'm worried that this maybe not the case as I poked a hole in it.  How will this effect the running of the car?  Anybody know?

 

It won't affect the running of the car.

 

However, you're clearly out of your depth with this and you need to go pro, a new breather box is about £80 and fitting is about 15 minutes work with the car on a lift, the pipework itself will be fine, ask the mechanic to give you the old box back so you can clean it, simply chuck the old box in an ice cream tub, submerge in degreaser and leave to soak, after a few days you can clean it out using using some washing powder dissolved in hot water then clean cold rinse and leave it to dry somewhere, then next year you can swap it out and repeat the process.

Oh d**n!  That membrane was a disk which is part of the mushroom valve.  It's come off in one piece.  It might be impossible to get it back on.  Any advice?  How does this work?

Thanks sepulchrave.  Do you now what the mushroom valve is for and is it possible to re-attach the 'membrane'.  Yes....lesson learnt.  I'm out of my depth.

Thanks sepulchrave.  Do you now what the mushroom valve is for and is it possible to re-attach the 'membrane'.  Yes....lesson learnt.  I'm out of my depth.

 

Yes, that valve prevents fungal spores from entering the inlet plenum and thence growing into a nice patch of mushrooms.

 

Just kidding, it's a valve to prevent an overpressure event in the inlet from pressurising the crankcase.

I'm sorry but I'm not sure how to find out whether it's a BBY or A.  I've tried searching on the web but no joy.

Take a look in your car's documentation, or if that is missing, the identical information "label" in the spare wheel well, that label holds a few clues as to what bits are in your car, there will be an engine field and a gearbox field etc, the engine field will either have A** in it or B** - in each case three letters., you might be lucky enough to find it on the cambelt cover.

 

Just kidding, it's a valve to prevent an overpressure event in the inlet from pressurising the crankcase.

 

That sounds pretty important.  Isn't it?

 

That sounds pretty important.  Isn't it?

 

Theoretically, however such events are extremely rare so I wouldn't worry too much if you've broken it.

Take a look in your car's documentation, or if that is missing, the identical information "label" in the spare wheel well, that label holds a few clues as to what bits are in your car, there will be an engine field and a gearbox field etc, the engine field will either have A** in it or B** - in each case three letters., you might be lucky enough to find it on the cambelt cover.

I've looked in some documentation and it looks like it's AUB (Engine Code).

Theoretically, however such events are extremely rare so I wouldn't worry too much if you've broken it.

 

And if such an 'event' happens.....what actually occurs?  Sorry to be such a pain.

I've looked in some documentation and it looks like it's AUB (Engine Code).

 

Yes, that what I was guessing it would be, so the air/oil separator for that car will be cheaper than my one, and sounds like easier to clean - as you have been advised, although to do what has been suggested you would need to buy a new second one. Maybe, if you hand it into a garage, AND, they do replace the separator, you should tell them to return the old one for you to clean up and store in a warm dry place (airing cupboard) for repeating this task next year.

 

Years ago, when the crankcase systems were not sealed, I used to have a spare venting cap which I treated to a clean in an ultrasonic bath using Freon!!! Sorry Earth, I was probably not alone in doing this!!!

Edited 17 December, 201312 yr by rum4mo

And if such an 'event' happens.....what actually occurs?  Sorry to be such a pain.

 

There is a small chance there could be a combustion event in the crankcase, not a chance the manufacturer can afford to take, hence the valve.

This mushroom valve doesn't happen to look like this?

 

 

I only ask 'cos on my '91 Golf there is such a thing, and it's called 'mushroom type valve' in ETKA, and only a couple of years ago was available separately under part number 026 129 820 for a few quid. May well still be.

 

Sorry if this is a bum steer.

It does look similar except it doesn't have the 'handle'....just a hole in the middle.  Did I break off what was attaching it to the vent hose I cannot say.  I'm beginning to think that this hard resin type stuff I managed to remove was holding it in place.

It does look similar except it doesn't have the 'handle'....just a hole in the middle.  Did I break off what was attaching it to the vent hose I cannot say.  I'm beginning to think that this hard resin type stuff I managed to remove was holding it in place.

 

Humm, maybe, best to replace that pipe assembly though it is not unknown for individual parts to disappear from newer model's part numbers - for example, just try to order in ahandbrake equaliser yoke for that car, if I remember correctly "not available" "must buy complete handbrake assembly" - or if you are smart, order one in for, again an old Golf - exactly the same part - that will be due to VAG being supplied with the handbrake handle/cables etc as a complete assembly for easy cheap and quick fitting at the factories.

Should I try and re-attach the old mushroom valve for the time-being?