egr valve - mot requirement?

[dervman]

Hi all

The egr in my 2.0 tdi dsg needs replacing - need to get it done, but my first MOT date is first thing in the new year - ive read other threads about its only there to prevent shudder on shut down so my questions are
1). will i need the egr replaced for the emissions test (or anything else)? and
2). will a warning light on my dash prevent me from passing?

Thanks for your help

 

[james.g]

Not sure where you've got your info, but it's about as accurate as a politicians expenses...



The EGR system recirculates NOX from the exhaust into the inlet. This reduces emmissions and combustion temps. Depending on how badly defective your EGR valve / system is, it may or may not cause you to fail the emmissions test. Chances are if it's not woking you'll be seeing reduced mpg or performance - or both!

 

[dervman]

Thanks for the reply.

I'll get on to my Ministerial team and ask them how they could inform me so badly!

A dealer indicated at a service a few months ago that it had no real effect on the car and didnt present a problem and i could get it done whenever it suited, so i just havent bothered; theres been no obvious sign of increased consumption / loss of power, so i just drove on.

So, youve just confirmed my thoughts - emissions will be affected if i dont sort it - cheers. Downside is i suppose i wont have as much drinking money for Christmas now

 

[james.g]

Ha, ha

Before you go spending hard earned dosh, most EGR problems are down to carbon build-up and can be largely addressed by using an EGR cleaner spray or a strip and clean. Exactly what works depends on whether your car has a vacuum or electro-mechanical system, but it's always worth trying a clean before you replace the part.

I don't profess to be a VW group specialist but EGR systems are generally either:
1. Vacuum valve
2. Vacuum valve + solenoid valve
3. Stepper motor variable valve

All three types are susceptible to carbon build-up which tends to make the valves stick. Stepper types can suffer corrosion product clogging interfering with the armature. A good clean can go a long way to solve all these.

 

[Viking]

How do you know the egr needs replacing?

On the 2.0ltr TDI the egr is right next to the antishudder valve, and this is notorious for burning the motor out and throwing a fault code. Is this what you're talking about? If so it's not an mot failure or anything, as it just closes a flap in the intake to stall the engine when you switch off.

 

[CrispDust]

Egr is on top of anti shudder valve. If you're egr is fooked it may be stuck open - this will affect mpg /performance. There is also a motorised falp at the exhaust end of the egr I think. This can fail or fault too.
None should affect your MOT unless the egr body is really choked up.

 

[Art0ir]

Can't you just remove it?

 

[CrispDust]

Only if you have a replacement straight pipe. Easiest thing is to take it off, clean then either unplug the vacuum feed or put a blanking plate from exhaust feed. However both will throw a cel fault light.

 

[AndrewJB]

EGR Removal is common on 1.9TDI PD130's

Remove it , Fit a straight pipe instead and then get it mapped out

Pros of doing this on the PD130 atleast are that the Manifold Temperature comes down

 

[loadswine]

I have a spare egr that we can discuss if you still need it. I had my intake manifold flap mechanism fail, but my original egr valve was just encrusted with vast amounts of carbon which I cleaned off. Might be that's all that's needed here.