[Engine] EGR Valve. Clean or replace?

[darrenchadwick]

Dear all
Ive got an unresolved issue with my 2ltr HDI van (2006). Engine starts, ticks over and runs pefectly until accelerating beyond 2000 revs. Above 2K revs it dies and surges almost in a rhythmic fashion but then starts to die more than surge. If I drop the revs below 2K it instantly recovers and its fine. If I keep my foot on the accelerator and try to keep it above 2K revs it doesnt like it and starts to starve its self of fuel and would stall. I fitted a new air and fuel filter but no cure. Mentioned it to my local mechanic and he said its probably the EGR valve. It hasnt been hooked up to any diagnostics yet mainly because my local garages diagnostics (Im high up in the Yorkshire Dales) isnt reliable (their words not mine). So, just wondered whether to clean or just replace the EGR valve as an experiment but I dont know how awkward a job it is. It looks reasonably accessible. Any advice about the fault or about the EGR valve very welcome.
Should add Ive not got any engine management lights showing or STOP light, all seems normal apart from the 'above 2K' reving issue.

[Johny555]

Give it a clean see how it goes,

[ffrenchie]

Disconnect the MAF sensor on the air intake pipe and see if that makes any difference. Mine went and it gave the symptoms you are showing. A new one cost me about £40 but it was worth it.

[darrenchadwick]

Thanks Frenchie. Im only guessing but does MAF stand for main air flow? I dont know where the sensor is but Ill have a poke around at the weekend. The annoying thing is that the fault is not continuous. It has had spells where it didnt happen. Today it drove badly from the start of the journey with the typical sporadic fuel starvation sympton at 2500 revs. Then later in the trip it ran fine for a few minutes before going back to being a pain again. Its mostly faulty but not always. I have a hunch its an electronic fault rather than mechanical or fuel blockage because its so sudden when it happens. I might be wrong of course but bizarrely it returns perfectly to normal the instant if I drop the engine revs just below 2K revs.
Thanks for all the help.

[geoff]

So, just wondered whether to clean or just replace the EGR valve as an experiment

Given the ease with which an EGR can be removed for cleaning then it would be worth doing, I always advocate the free and easy work first as to spend money for an experiment goes against the grain with me sorry .... anyway how else are folks going to learn ???

[cancunia]

From what I've read, unless you're overly concerned about emissions on low revs, it's worth removing or disabling the EGR anyway as they're likely to fail at some point. Blanking plates are available for about 3 pounds and can be put in place quite easily from the looks of things.
I've not done this personally so would be interested in opinions on this.

As an example, this is made from stainless so should last.

http://www.ebay.co.uk/itm/EGR-Valve-Blan...xy2LJRBYHl

[brodfather11]

Your MAF sensor, (Mass Air Flow) measures the amount of air going into the engine ,simply put it adjusts the fuel delivery accordingly .
It will be in the pipe between the air filter and manifold.

[ffrenchie]

Thanks Frenchie. Im only guessing but does MAF stand for main air flow? I dont know where the sensor is but Ill have a poke around at the weekend. 

Maf is mass air flow and the sensor is in the pipe from the air filter to the intake manifold. Lift the bonnet look at the rubber pipe and there is a black plastic cylinder with a grey connector and wires. Disconnect it and start the car it will take 3 minutes at most and you will know if it making a difference. It does not show any fault code or engine light so why leave it till weekend when it is so simple ?