Hi,

 

Anyone done an EGR Valve clean or swap-out?

I'm getting repeated Engine inspection light, or what the manual calls "Control system for exhaust".

There's no change in performance, and not got to point of flashing Glow plug light or DPF faults.

 

I'd like to open the EGR Valve and see if it needs cleaning. Seems a common situation with modern emission controlled diesels.

 

Anyone know how complicated it is?  How long would it take?  It would be great to find a guide workshop manual account of what's involved.  It looks like just  3x hex bolts,  but its in a tight location.

 

Here is a picture of the EGR Valve.

Thanks in advance

 

 

Sorry - can't help you with the EGR.

 

But rest assured the fault won't be DPF.  Roomster 1.9TDI doesn't have one.

EGR on the old PD do get gummed up, but normally it is a replacement, fairly easy job

 

take off the big air pipe (a pull up clip) and split the pipe a bit further down so you can remove the pipe

 

you have 8 x 5mm hex bolts, 3 on the antishudder valve in front of the EGR and 2 or 3 connecting the EGR to the manifold and 2 connecting the EGR to the turbo

 

remove the vaccum lines and take the EGR out

 

at which point have a can of carb cleaner and a tooth brush to hand and away you go, also have a look at the point it connects to the turn to make sure it is not blocked.

 

some have had success cleaning them, others haven't

 

I think you can get 2nd hand replacements on ebay for about £30-£40 or less depending on the "guarantee"

Ive seen these being blanked off on other vehicles, could the same be done and would it make any difference to the running of the engine.

Ive seen these being blanked off on other vehicles, could the same be done and would it make any difference to the running of the engine.

yep, know as EGR delete

 

but it needs programming of the ECU as well

Hi,  Thanks for all the helpful posts ! 

When I started exploring the ERG valve,  I discovered a broken vacuum pipe,  and I'm currently working on that line of inquiry.
 
A bit of back story in my case.  Last week I put the car into an independent VAG garrage to have the suspension coil replaced. The bottom coil had snapped off, and was making a jangling noise when ever the wheel went over a bump.  The vacuum valve and junction box is mounted directly ontop of the suspension coil, driver's side.  So it seems very possible that the plastic spigot for the rubber tube was broken by the engineer working on the suspension coil,  and grabbing the side of the plastic junction box.
 
The replacement part is £45 + VAT  and looks a bit like an octopus, consists of the connection strip with 5x tubes and the rubber 'legs'. I think VW TPS had to ship it from Germany [or Czech]  cause its taking 2 days to get to Guildford, Surrey.   So I'm hoping that when that is fixed,  the vacuum 'pressure' will be restored to the ERG valve, to allow it to work again at high revs.  Then I just need a VCDS kit to clear the fault codes / Diagnostic Trouble Codes on the engine management controller.  And back to a MOT/road worthy car.
 
Image of broken vacuum connector.

Edited 2 June, 201511 yr by wwoking

The broken vacuum connection will cause the problem you have. I had the very same issue when an overzealous approach to something or other on my part fractured a connection on the box you describe.

£45 seems about right. Ensure that you take a picture of the where the vacuum tubes connect before you pull them all off to fix the new box in place.

Assume your user name is a clue as to your location?

If so, search the VCDS owners map to find a friendly local Briskodian to extinguish the CEL for you

Ive seen these being blanked off on other vehicles, could the same be done and would it make any difference to the running of the engine.

 

Ho, ho,  This is effectively the situation I currently have. The upshot of this is that I get an Engine Warning light on the dash,  and that renders the car an MOT failure. 

 

I believe the  EGR valve is failing to open at high revs,  due to a failure of the control signal reaching the EGR valve and opening it.  I believe the EGR is controlled by a supply of vacuum suction,  under the control of the  -N18- Exhaust gas recirculation valve [to quote the service manual].  And this is failing due to a broken tube on the supply of vacuum suction. 

 

This pesky modern car has way too many temp/pressure sensors and electronic control circuits for my liking. At least now that its starting to spring failures and need some attention to bring it back to a smooth running MOT/road worthy car.

 

As I understand the purpose of the EGR and its impact on emissions,   the objective is to cut down the nitrogen oxide NOx gas,  which is created in a narrow range of engine temperature,  once the engine has got heated up.  By feeding some of the exhaust gas back to the inlet manifold,  the engine designers have achieved 1) cooling the engine down to a point where less or no NOx nitrous oxide gases are generated, 2) unburnt fuel is burnt. So the emmissions are better for the environment and future generations :-)    The cost of exhaust gas recirculation is that less 'moving gas' energy if fed into the turbo, and so less power is delivered by the engine. Which is less exciting for the driver of the car,  but probably better for their fuel economy.

 

I have posted references to other forum posts that give more background of ERG systems  and ERG blanking-off,  in VW Transporter diesels,  and a YouTube vid of  cleaning an ERG on a Peugeot Clio,  using oven cleaner.

http://www.briskoda.net/forums/topic/272158-egr-fault-is-this-common/#entry4262571

the EGR opens under low engine loads when the engine is running at its leanest mixtures, under these conditions the combustion temperatures increase and cause more NOx emmissions

 

to reduce this the EGR opens to allow exhaust gasses into the inlet manifold , this has the effect of reducing the amount of oxygen in the cylinders and reduces the "leanest" of the mixture and so reducing the combustion temperature and NOx emmisions

 

the various sensors in the inlet side can work the amount of air coming in through the air filter, and how much exhaust gases are being fed into the inlet manifold, hence it can tell when the EGR is bust and light the MIL lamp

 

as to the octopus of rubber pipes, have fun it is not to bad, one goes to the air filter, one goes to EGR, one goes to turbo wastegate (down back of the engine, easiest to access from underneath with car on ramps) one goes to the T piece on the brake servo line (this is where it gets the vacuum feed) and one goes to the vacuum reservoir (round ball on front of the engine)

^  Very nice description of how it works.

 

It's peak combustion temperatures that are lowered, which isn't the same  thing as "cooling the engine down", even though it might sound like it.

And nothing to do with burning unburnt fuel.

Hi.

For some reason I joined the forum yesterday. As it happens I'm in the process of changing my 1.9tdi Roomie for a 64 plate 1.6tdi scout Roomie. (I've put down a depisit). So I started looking at forums and before you know it I'm a bit panicky that I've made a mistake. The issues around DPF's and EGR's are the reason. I live in a village and a fair bit of the driving will be trips to the 'big city' which involves about a 25 minute drive. Sometimes the trips are longer, maybe up to an hour or so.

I don't want to have to go out on social trips to clear DPF warning lights. My mother in law has a 10 plate fabia 1.6tdi and had EGR problems a year or so ago yet she does a lot if out of town driving. She got a goodwill discount off the price of the repair but was still out of pocket a fair few quid. Her husband on the other hand got a Roomie 1.6tdi about a year ago and has been trouble free.

I really do prefer diesels and the 1.6 seems pretty smooth. I see that a lot of folk on the forum love the 1.2tsi but I'm not convinced. I don't want to change my mind about the new car so am wondering what folk think about the matter. I'm also thinking that because the car is only 6 months old (newest car I've ever had) and only cost 10k (cheaper even than a lot of tsi's) I'll probably aim to change it shortly after its 3rd birthday.

Any feedback greatly welcomed (and sorry for going off at a regent from the original post but I don't think I'm allowed to start new threads of my own yet as I'm a newbie).

if you have a 25 minute so long as it isn't all low speed twisty roads you should be ok, the biggest enemy of a DPF is short runs with no longer runs to allow the DPF to regen properly

 

a school run mum with only a couple of miles each way is not for a modern diesel,

 

a modern diesel will do a passive regen about 150-300 miles depending on conditions (number of cold starts etc), so long as you don't ignore any warning lights to give it a drive to do an active regen you should be ok

 

EGR valves are normally good for 80,000+miles, our old VRS mkI fabia had a EGR failure at 95,000 miles and 10 years

 

good servicing and understanding how the parts work are the key

Indeed. Thanks. Yes I will relent and use the skoda dealership for servicing at least whilst it remains in the warranty period (haven't owned a car with a proper warranty before)..... difficult to overcome your roots..... ie tight Scottish git!

Hi,  a couple of updates. 

 

1) Problem solved with MIL light.  By replacing the damaged plastic junction connector on the 'head' end of the octopus of vacuum pipes,  I seem to have fixed the problem with faulty exhaust gas operation.  It was easy to pull the pipes from the unit at the top of the engine bulk head,  and the pipes+connector are labeled with numbers,  so you don't get the plumbing mixed up.

 

2) This Roomster 1.9 TDI DP has done 45k miles, and has a good mix of  30min daily commute and once a month 3 hr motorway journey.  So there should be no problems with soot build up. Except where it gets gummy in the inlet manifold when mixing with oily air from the engine.

 

Bizarrely,  the fuel gauge display has stopped moving since the fix.  I'm investigating that now,  and wondering if the use of an unregistered [reduced function] VCDS-Lite software + Ebay interface cable are mis-programming the settings on the car?

 

I'm going to run down the fuel level to see if its just an issue with the fuel gauge not showing movement till the tank is,  say half empty. I found one post where someone took a Fabia with same problem into a garage,  to be told 'the fuel tank needs adjusting'. They thought that meant a software download.   http://www.briskoda.net/forums/topic/193510-fabia-faulty-fuel-gauge/

 

And I found comments on other VW/Audi  VCDS users forums about how to test the operation of the fuel tank level sender [resistance of rheostat as the level drops],  and some options to adjust where the needle sits on the red warning level of the fuel gauge.  I'm about to discover if these features are available with the free-to-use  VCDS-Lite software. 

http://forums.vwvortex.com/showthread.php?4868432-Fuel-Gauge-Adaption-2010-Jetta&p=66099017&viewfull=1#post66099017

 

Wow,  I'm glad I'm not putting all these jobs into a main dealer.  The hours to investigate and diagnose the problems would cost more than my mortgage!