EGR valve inspection/cleaning on 16v/1,4l (BBY) - a complicated task?

[gewstarr]

What is that thick red wire going across your engine, by the way?

 

Hehe, since this is a LHD car the drilled hole (through the firewall) for coupe heater is at the right side of the car (passenger), i.e. diagonal from the battery. I have a subwoofer lying in the trunk and the cable was just about long enough to make the run so it's a really wacky solution. It usually just lies on top of the plastic engine cover. It was though to be very temporary (till I got to buy longer cable) but it's been over a year. Time flies, really!

 

To be honest, you need to start at the beginning as I recon you now have an air leak after messing with the throttle body and egr system.

start by pulling the throttle body back off, and the egr spacer plate, make certain everything is spotless especially where the gaskets sit and clean the actual throttle body inside around the throttle flap, this will be covered in carbon deposits and oil from the egr and breather system, make sure everything is clean and refit carefully, then before starting the engine, do adaption 00 save, then basic settings 60 to adapt the throttle body, sometimes can take a few goes at this

and basic settings for the egr valve (cant remember if its 70 or 74).

also check with the engine running for leaks on the brake servo pipework they usually split where the joins are.

 

I've re-adapted 074 and 060 several times. No progress. Is doing 00 really absolutely necessary? Doesn't this reset just about everything. I'm not keen on needing to redo windows, central locks, etc.

 

Oh, well that's what it's for, that and for attaching a fuel pressure gauge for diagnostics.

 

Nice! I saw some article where they explained that most engines has a testing port for fuel pressure. I was actually meaning to ask here if the Fabia has such. Now I know. Those tools are pretty expensive (> £ 200) where I live though. I found one box on eBay (from far East) for only ~ £ 20 though. I wonder if this will fit, it was told to contain a 1/4" adapter. It said nothing about Schrader, though.

 

 

I'm not sure, but I think EGR may not be active at idle on petrol engines, so unplugging the valve then wouldn't make a difference.

 

I think just 1 or 2 amps will be plenty to move the valve. What you should probably do though, is use VCDS.  It has an 'actuator test'* mode where you cycle through operating things like the fuel pump, EVAP purge valve, EGR valve listening for them to work at each stage.  I confirmed a faulty EGR valve on our 1.2 by doing this actuator test a couple of times.  Absence of a heavy 'click' noise at the time movement is requested suggests a fault situation.

 

You could also measure the dc resistance of the solenoid between pins 1 and 5, if you can get probes into the connector. I can't remember now what is typical but maybe 6-12 Ohms territory?

 

* may not be the exact name, but it's something similar.

Edit: Looking at one of your photos up there ^, maybe it's "Output tests".

Oh. But then I guess I could let my lady hold the throttle steady on let's say ~3000 RPM while I stand before the engine bay and plug/unplug the connector, back and forth. Would be a sufficient test for seeing any instant results? Loved that idea about "Actuator test", you don't remember exactly what "Measuring blocks" page it was on? I found this article on Ross-Tech webpage, which seem to be a pretty handy for knowing what groups to look for. Not sure about how accurate it is for the Mk1 Fabia, though. I also found this old thread here on Briskoda, with someone getting output tests (really sorry for my bad grammar earlier) on resistance. I haven't done any Ohm readings myself just yet, but I did take the valve out just half an hour ago, took it in and with some help managed to test feeding it with a 12/2A power supply. Look below, you can see both sides of the valve. On one side, the pin in the middle is just spinning around, and on the other side, it's moving up and down, but it looks like it doesn't go all the way. I'm not sure about how it should look. Anyone who can lay me a verdict out of this?

 

 

Cheers!

[Breezy_Pete]

Hard to tell from your video whether the valve is staying open without current sometimes?

 

The VCDS thing is here I think?

 

[gewstarr]

My EGR valve may be healthy after all. Haven't got it confirmed but I found this thread where someone is checking his EGR valve with multimeter. Now I did the same, and my results are defenitely not far from his.

Between pin 1 and 5 -> 8.4O Ohm
Between pin 2 and 3 -> 2.13 kOhm
Between pin 2 and 6 -> 2.38 kOhm
Between pin 4 and 6 -> 1.03 kOhm

I guess this would pretty much rule out the possibilty of a faulty valve. One thing I haven't tried yet, though, is unplugging the valve and read voltage from the actual connector when pushing throttle, i mean to see that it's actually getting feed. Could be the loom / wire harness after all? Perhaps, perhaps. Oh, by the way, not to sound completely stupid but, if the valve is in fact a pretty basic thing, being either open or closed, what's the need for all it's pins? Shouldn't two single pins be enough? Or is the EGR acting some sort of controller itself? Pretty confusing.

 

Another thing I wonder is about the possibility of some clogged hose. You know the black rubber hose that goes into the engine cover (containing air filter). Should I feel either blowing or suction from this hose when the engine is running? If so, it's probably clogged, because it's completely windless calm from that hose. I also found this ancient thread about the crankcase breather. I'm getting confused of all dozens of possibilities. This couldn't have nothing to do with my situation, now could it? I will run the "Output tests - 03" in VCDS Lite tomorrow, @Wino.

Edited 14 November, 2015 by gewstarr

[sepulchrave]

Your breather is clogged, you should be able to blow down the tube and pressurise the crankcase yourself.

[Breezy_Pete]

EGR valve isn't just open or closed, it can be at any position in between those extremes.  The power to pins 1&5 will be pulse width modulated to achieve differing levels of pull from the solenoid. Balanced against the return spring, this will result in partial openings, the exact position being fine-tuned by the ECU getting position feedback from the potentiometer.

 

All that aside, because of its high temperature working environment, and with it having a moving part, mechanical (sticking/sealing) issues are just as likely as electrical, if not more so.

 

Most EGR faults should produce directly related fault codes though, so you may be right to question whether there is a problem there.

 

Can you post a picture of the black rubber hose you mean?

[gewstarr]

Can you post a picture of the black rubber hose you mean?

Trying to blow air into it right now. It's not completely clogged but blowing takes some real effort, like twenty times more than to blow air into a balloon. Not sure how this passage is supposed to be, though.

[Breezy_Pete]

I wouldn't expect to feel much, if any, suction on that hose at idle. If you use your tongue instead of a fingertip, you may be able to feel a bit. If you unbolt the one-way valve at the rocker-cover end of it, you'll feel a little more suction at the hole in the cover, in my experience.

The one-way valve is just a little rubber diaphragm if I remember right. You can, with care, disassemble it to inspect, but there's not really much that can go wrong with it.

 

The idea is that a small quantity of fresh filtered air is drawn in there, to help ventilate the crankcase. The amount will vary with inlet manifold vacuum, and so the PCV valve's state of open-ness at the block breather assembly (minimally open at idle).

Edited 15 November, 2015 by Wino

[sepulchrave]

Surely shome mishtake?

 

Crankcases pressurise over time due to ring blowby, a PCV system is designed to actively prevent that pressurisation by using inlet depression to remove it. The one-way valve is designed as a flame trap to prevent any inlet backfire from travelling down the breather and detonating the air/oil mist in the crankcase.

 

I would be surprised if the breather labyrinth were not blocked since the OP lives in a colder climate than us which means more yoghurt formation from condensation.

[Breezy_Pete]

I believe gewstarr's PCV system is probably identical to the one on my Polo (just the one thin hose going up to airbox?), which is nearly identical to the 3-pot system shown here (differently positioned one-way valve and labyrinth/cyclone/PCV components, but functionally same):

 

 

 

I can say though that with engine off, I am able to blow easily into the rocker cover via the hose that the OP is pictured with. Removing the one-way valve from rocker cover, I can't blow out through it towards the air filter, confirming the edited comment at the bottom, regarding the directionality.

 

 

@gewstarr: was the engine running when you were trying to blow down that hose?

If so, it might be confirmation about sepulchrave's blocked labyrinth separator idea.  If the crankcase is pressurising, it will be harder to blow into there, against the internal pressure that isn't being negated by the PCV system.

Edited 15 November, 2015 by Wino

[sepulchrave]

That's the three cylinder Skoda engine. not the four cylinder VW engine, are you sure that the PCV system is the same?

[Breezy_Pete]

That's the three cylinder Skoda engine. not the four cylinder VW engine, are you sure that the PCV system is the same?

99%.

On mine, I've substituted my 120k cyclone/labyrinth/PCV thing (breather box for short) for a cleaned out one, and all those bits seem the same. The hosework is functionally the same - output of breather box goes to a point below throttle body, and the hose to airbox is same as his.  I think on earlier iterations of the engine, the output of the breather box went direct to airbox? Yours is like that isn't it?

[sepulchrave]

99%.

On mine, I've substituted my 120k cyclone/labyrinth/PCV thing (breather box for short) for a cleaned out one, and all those bits seem the same. The hosework is functionally the same - output of breather box goes to a point below throttle body, and the hose to airbox is same as his.  I think on earlier iterations of the engine, the output of the breather box went direct to airbox? Yours is like that isn't it?

 

It is. Mine has no separate arrangement for the cambox, just the labyrinth bolted to the back of the block and the hose going to the air filter, easy to keep clean.

[gewstarr]

Guys, I have some news.

Actually, I'm not sure if it's a laughing matter or a crying matter, but doubtlessly it's a bit comical when pieces of the puzzle are being put together.

Anyways, yesterday I sort of panicked about us going for a ~370 mile drive to my in-laws for the upcoming Christmas, not having a functional car. To make a long story short, me and my girls took the train to Stockholm, went to a dealer, and bought a 02-reg Toyota Corolla Verso with ~137k miles in the odometer, more or less without thinking straight, at all.



We drove our new car home. This was yesterday. Today, I went outside to continue messing around with the Fabia, even though I had pretty much given up hope on it. I reassembled the EGR along with pipework, and also the TB. Then I restarted the engine. It started, but hesitated, stalled, and were drive since not willing to even get into it's really rough state. I turned the key and tried giving throttle at the same time, sort of when trying to get an old cold carburetor car running. It hesitated, not willing to live. Suddenly the low fuel warning symbol came up, along with it's beep. I decided to not kill the battery entirely by tormenting the starter engine. I got a 5 liter plastic gas tank and took my bike down to the station and got it filled up. Back to the parking lot, filled the tank, and tried starting the car again. Now engine fired up, but it was really rough. Sounded even worse than before.

 

So, earlier I had constant misfire specifically on cylinder 1 and 2, hence my belief that I was dealing with an air leak, since this online article had explained cause and effect pretty well.
 

The leak may cause the nearest cylinder to run leaner than the others. The ECM will indeed richen up the overall mix in an attempt to bring the excess oxygen in the exhaust back to the appropriate low level — but that will force the other cylinders to be too rich, which may cause a whole menu of issues — misfires, unstable idle, etc. — that might set a trouble code and turn on the Check Engine light.

 

Anyways, I had taken out all plugs / coils in order to perform that compression test earlier, and since that they had just been lying in random order on the floor of the car. Now I had re-plugged them, just as randomly. When I re-read codes in VCDS Lite at this stage I seemed to get specific misfire on cylinder 1 and 3, all of a sudden. After clearing and re-running, the same codes reoccurred, over and over again. Three times, four times, always the same first and third cylinder. Weird, huh? I did some more swapping only to make sure it was consistent, and then let one earlier assumed dead spark coil back into play, and redid the test. Now there was suddenly only one cylinder misfiring, #2. I suddenly recalled what I had been told at an earlier stage in this discussion, "It's electrical", an idea which now re-bloomed in my head.

 

I got on my bike and went to Biltema, which is pretty much a Swedish equivalent to Halfords. They have aftermarket spark coils and I always buy them there since they are roughly half the price of OEM VW coils. Unsure about how quality differs, but when I bought this car there was only VW coils and two of these were burned in only a four month period. Anyways, now I bought myself one, and bicycled back and swapped the final spark coil. Cleared codes, and restarted engine. Voila, all of a sudden I had smooth running again. Did play with the gas pedal and revs came smooth as a whistle, no sign of engine management light coming on.

Now, first I suspected that the spark coil that I had had lying in the trunk in case of emergency ever since this summer had simply been bad from the get-go, and that this stupid aftermarket piece had not only led me not only into spending days of beating around the bush for troubleshooting, but also into going for a new car. To be honest, I was pretty angry for a moment there. Now, what's done is done, and it got to be a somewhat happy ending after all, right? I gathered my two bad spark coils from the asphalt and laid one last good look on them.

 

Then I noticed something. The black rubber gasket in one of them was much thicker than in the other one. Really weird. Then the pieces fell into place, in just a second. You know that rubber piece that is often seen inside of spark coil sockets, to help one fish the spark plug up from the hole? Earlier when changing spark plugs I had noticed that the rubber on my spark plug socket was only like, half, but I had quickly dismissed it as something that came from some earlier episode. Now, however, I finally understood it all. When I had messed around with the spark plugs earlier, one spark plug must have had the rubber piece still on it when I pushed the spark coil onto it. Damn it, I recall how I noticed how one spark coil felt stiff in the end when pushing it down, but I had dismissed it like some sort of other wear.

Yeah guys, this story is comical and tragic at the same time. I was inattentive when doing the spark plugs, a piece of rubber from the socket managed to get stuck into the new spark coil, not allowing it to sit hence work properly, leading me to think the problem originated elsewhere in the system. I still wrap my head around trying to figure how in the process I ended up with two bad spark plugs, given I replaced one that was obviously dead with a new one I managed to get a blocking piece of rubber into, should be only one bad coil in the cylinder bay, in total? Anyways, I did lots of swapping in desperation, so I must have thrown the first faulty one back in somewhere in the process.

Anyways, I'm not bitter, not at all. Before this mess, I had never dared touching the petrol fuel rail or it's injectors, I didn't know where the MAP sensor sat, and I did not know that you could push the rear seat forward and gain access to a hidden lid where you can unplug and withdraw the entire fuel pump assembly from the fuel tank. I have learned so much through this lesson, and grown as a person during the process. Also, now I have not only one but two cars in my possession. I look back at an encouraging one-liner ("Keep fighting, you will win") dropped earlier in this thread, and find myself smiling.

Yeah, I finally won. Can't thank you guys enough for being on my side throughout this long journey. I would have collapsed early if I hadn't had the great support from @Wino, @sepulchrave, @rum4mo, and @felicia16v. You guys are the best, I don't think any car brand in the world has this awesome online community.

Cheers!

TL;DR:
Car runs great now!

Edited 15 November, 2015 by gewstarr

[Breezy_Pete]

Glad you fixed it in the end.

In my opinion, it's always good to explore new areas of your car that you haven't got involved with before, life is one long school-day.

  

What's the Toyota like to drive; I've never driven one?

Edited 15 November, 2015 by Wino

[rum4mo]

That is excellent news!  The trouble when chasing problems sometimes is that you get tunnel vision - and it can only get worse the longer the work goes on. As you have said, you have been forced to take things apart that you would never have thought about being confident enough to take apart - now all you need to do is to store that information in your head for a long time - just in case!

 

So, which car is it for the Christmas trip - Fabia to prove your "car fixing ability" or Corolla Verso in case you get too many presents?

 

Ah well, it will be easy to laugh about it now, though certainly not at the time when you were thinking that the car had beaten you.(time for some beers?) - I would think that it is getting a bit too cold up over there for working on cars outside.

 

Enjoy!!

 

Edit:- Just a thought, what is next, or how are you going to spend all the free time that you now have - preparing for Christmas maybe??

Edited 16 November, 2015 by rum4mo

[Jamesgil]

Hi there,

 

Greetings from Dominican Republic! I have one question, been getting a related code with VCDS P3130 (EGR) Limit Exceeded 

I have a Skoda Octavia tour 1.9 TDI 2006 Engine code : ALH 

My EGR is leaking fromt the side, the mechanic said he took it off and cleaned it and put it back, I don't think he put new seals or anything like that, then erased the codes, but the CEL light came back on within days. The EGR is visibly leaking, but I have read on this thread that if you take it off to clean and then put back on again, it needs to be 'readapted' with VCDS? I don't think the mechanic did that, he just erased (reset) the codes. 

I am planning to take off the big pipe that goes into it from turbo just to see if I can visually inspect that the diaphragm is in fact moving (opening and closing) if I turn the engine one without the pipe. Although I don't have a lot of mech knowledge, thanks to Briskoda I am learning about this problem as I have just bought this beautiful car, I am although thinking of replacing the hose that goes into the EGR, as I can see that it is a bit damaged (lots of strings from the weaving have come of) as the local Skoda Distributor in the country wants aprox $600 US for a replacement valve, I just want to see if it is a leak of air that is setting the code, and to be 100% sure that I have to ABSOLUTELY replace it.

 

Many thanks in advance,

 

James 

Edited 5 August, 2016 by Jamesgil

[Breezy_Pete]

Diesel EGR valves are very different to the one being discussed in this thread.  You would do better to post the same information in a new thread in the Mk2 Octavia forum (assuming your car has 1Z in the VIN number; if it has 1U go for the MK1 Octy forum).

[lunga]

Hi Guys.  I would like to know where the vacuum pipe from the EGR connects to.  My vehicle has displays EPC.  I have changed everything. MAP sensor,EGR valve, Coils. Still without solving my EPC problem.  I have taken it to different mechanics to solve the problem and even went to the dealer to no avail.

I have the following error code

Barometric / manifold pressure signal

    p1553 35-10 - Implausible Correlation - intermittent

 

Intake Air system

   p1504 - 35-00 - leak detected

 

readiness : 1010 0101

 

I have noticed that the pipe from the EGR is cut short and a bolt put inside to cover the air from entering I figure.  It is not connected anywhere.

 

 

Your help is greatly appreciated

[sepulchrave]

I'm guessing you have a petrol engine of some sort, we need to know what sort.

The vacuum pipe is not a vacuum pipe, just an air pipe which usually goes to the filter box or simply vents to atmosphere.

You need to repair the EGR system with new pipework and get it working or you'll never get rid of that EPC light.

[rum4mo]

Are you sure that it is a bolt that someone stuffed up that small air pipe end, or is it what it should be a plastic rough and ready filter to stop any major nasties getting drawn up that small pipe.  If a bolt has been stuffed in the end of that pipe, that EGR might now have problems as a theory was that that small pipe was to allow some air to pass through the body and so slightly cool the EGR assembly.

 

Back to basics, checked that the pipe from the EGR valve "output" - or at least where that pipe goes at the Throttle Body, has a clear air way into the manifold and is not choked.

 

Remove the MAP sensor and carefully spray clean it and refit.

[lunga]

It's is a petrol engine. Here are pictures of the eye and the pipe I am concerned about.  

So I must change the EGR pipe system not the only the EGR itself?

[sepulchrave]

Yes that pipe is supposed to vent to the atmosphere, not vacuum. Remove the bolt blocking it. Reconnect the EGR valve and disconnect the battery for a few minutes to clear the ECU.

[lunga]

Thank yo very much, I will do that.  You have been very helpful.

[Malume]

I have the same problem with my egr valve i try to clean it and that silve pipe and throttle body but still show error P0401?

Edited 26 April, 2020 by Malume

[sepulchrave]

1 hour ago, Malume said:

I have the same problem with my egr valve i try to clean it and that silve pipe and throttle body but still show error P0401?

 

If the error clears when you unplug the EGR valve then you need a new one.