EGR valve

[Guest 4123]

In theory yes but in practice the EGR becomes less affective at NOx reduction as engine mileage increases. As cars are only tested when new to check that they comply with the euro 3 / 4 etc standards they pass, but if the same engine was to be checked at say 50k miles the NOx will have increased due to the lack of effectiveness of the EGR plus general engine wear
If you replace or clean the EGR and the inlet manifold etc then the NOx will drop as the EGR will be more effective. It will not drop to the original levels when the engine was new
however the EGR will always increase particulate matter so by disabling the EGR the particulate matter will be reduced (this is what the mot tests for) and the NOx will not be increased because the EGR and I let manifold are already coated in crap

Any evidence to support this theory?

This is my take on the EGR after a lot of reading some years ago.
90 % of NOx is created by domestic combi boilers anyway so if I can reduce particulate matter then I'm doing what I can to run a cleaner engine.

According to this article:

https://tfeip-secretariat.org/asset.../Ghent-2014/KKing-London-Domestic-Boilers.pdf

in London, heating systems using natural gas are responsible for 16% of NOx emissions.

RAB

 

[Dave M]

I think you mean Euro 5. There are diesel A2's that meet Euro 4 (ANY, BHC & ATL) and they don't have DPF's. Any evidence for this being a cause of neat diesel getting into the sump? Very doubtful indeed!

Deleting EGR is illegal for road use and you can be fined up to £1,000 I believe.

RAB

Is disengaging the EGR via a remap illegal RAB or does it refer to the physical removal of the EGR valve ?.

 

[Guest 4123]

Is disengaging the EGR via a remap illegal RAB or does it refer to the physical removal of the EGR valve ?.

They are both illegal because in function they are the same. With EGR disabled, your vehicle will not meet its emission standard.

RAB

 

[Dave M]

Understood thankyou.

 

[A2Steve]

I physically have no egr valve in place and it passed the MOT fine with emissions of 0.33

 

[Guest 4123]

0.33 of what? NOx is not measured as part of the diesel MOT, only smoke, which does not mean PM.

RAB

 

[Olerype]

I think you mean Euro 5. There are diesel A2's that meet Euro 4 (ANY, BHC & ATL) and they don't have DPF's. Any evidence for this being a cause of neat diesel getting into the sump? Very doubtful indeed!

Deleting EGR is illegal for road use and you can be fined up to £1,000 I believe.

RAB

My 2007 Touran is Euro4L and has DPF.

Google diesel in oil due to regeneration of DPF. I will also try to find VW own litterature on the subject. Problem is the post injected diesel that does not combust but is supposed to end up in the DPF to generate heat, but instead end up in oil sump. Reason for longlife intervals of 30000km never is a good idea; make a oil analysis at 8-10000km and you will see that the oil is degraded already.

No fine for disabling EGR in Norway. It would fail MOT but they do not check the software/emissions for such.

 

[Olerype]

During regeneration the fuel consumption approximately doubles
—
A disadvantage of active regeneration is engine oil dilution caused by small amounts of fuel entering the engine crankcase during the post-injection phases. This has made it necessary, in some circumstances to reduce the oil service intervals.
—
Some examples taken from here;
https://www.honestjohn.co.uk/faq/diesel-particulate-filters/

 

[andrewparkeruk]

Is disengaging the EGR via a remap illegal RAB or does it refer to the physical removal of the EGR valve ?.

@Special edition Dave this is a UK government article I found
https://www.gov.uk/government/publi...ions-the-legal-safety-and-health-implications

Andrew

 

[Bri957cc]

When disconnecting the vacuum pipe from the EGR (and plugging it with a suitable sized bolt), is it necessary to plug the exit from the silver flying saucer as well?

 

[Catnip64]

When disconnecting the vacuum pipe from the EGR (and plugging it with a suitable sized bolt), is it necessary to plug the exit from the silver flying saucer as well?

There's no need to block the pipe to the vacuum actuator. I assume that you have a 75 TDI?

 

[Bri957cc]

There's no need to block the pipe to the vacuum actuator. I assume that you have a 75 TDI?

Yes, just a 75.

Is there a diaphragm in the actuator? Just wondering if it was split, if that could affect running when exposed to air when the vacuum tube is disconnected.

 

[Catnip64]

Yes, just a 75.

Is there a diaphragm in the actuator? Just wondering if it was split, if that could affect running when exposed to air when the vacuum tube is disconnected.

Yes, there's a diaphragm in there. but it vents to atmosphere through a small hole in the body of the EGR, so it won't have any impact on the running of the engine. Of course if it's already split, then removing the pipe won't have any affect!

 

[Bri957cc]

So if the diaphragm is split, or the pipe is disconnected - the EGR is effectively disengaged and no air is diverted into it? all gasses will flow straight into the exhaust?

 

[Catnip64]

So if the diaphragm is split, or the pipe is disconnected - the EGR is effectively disengaged and no air is diverted into it? all gasses will flow straight into the exhaust?

Yes, it's spring loaded in the closed position, so no exhaust gas will get into the inlet.