C5 2.0 hdi 110 egr issue

[Dac02]

Hi all
Sorry if this has been asked a million times before but cannot seem to find a diffinative answer, I just got a 2004 C5 2.0 110 auto Diesel and its gone into limp mode, wont rev past 3000 and hardly any power, eml light and service on. Plugged in to obd2 reader and throws up p0401 egr valve fault. Never has an egr on a diesel before but looking at it there does not seem to be any sort of electrical connection to it. Is this normal?
Is it just a case of removing it and cleaning it up?
Thanks in advance

[spider]

Removing and cleaning it would be a good idea.

I think (later models) are electrical but there is generally a vacuum hose to it as well as one (or two for later models) solenoids to control the vacuum. One to actually open/close and one to regulate it.

The solenoids may be fitted to the bulkhead area. I'd actually start by examining all the small bore vacuum pipework simply as this is slightly easier than getting at the valve. You may find a perished or split / disconnected vacuum hose is the cause possibly.

[Hell Razor5543]

Sometimes a proper EGR valve cleaner can work, but make sure to not only follow the instructions on the can, but see if there are any warnings (either on the can on the makers' website), as spraying in too much could cause the engine to run away.

If it works, the EGR cleaner can cause the crud to break down and allow the EGR valve to operate smoothly.

[Dac02]

Hi
Thanks for advice will examine all hoses tomorrow and look for splits, 1 thing I didnt mention was that when you start her up and hold the revs high it will sit there quite happily with your foot down but once you stop 5-6 seconds and eml light and no power.
Thanks

[Dac02]

Hi didnt see the second post but have heard bad things about egr cleaners doing more harm than good. But might be left with no choice as it doesnt look like a simple job to remove the thing.
Thanks

[Gibbo2286]

Check all those thin vacuum hoses carefully, they can have tiny splits very difficult to see.

I've not seen a C5 with an EGR itself actually faulty, almost always a lost vacuum or faulty electrovalve.

Looking from the front the control valves are to your right hand and back against the bulkhead under the plastic cover.

[Dac02]

Hi
Got the egr valve off along with the the tube attached to it, the valve does still move with a bit of force and was fairly clean. The tube it was attached to was filthy with black gunge, also the large metal unit the air intake is connected to was full of black gunge. Not worked on diesel engine for 15 years, they are very different now.
Going to put back tomorrow as is now chucking it down

[SwissSPEC]

Mine was all gunked up as well, but i had no error, so err'd on the side of caution & got the egr blanked off. Car is more spritely as a result & of course it's never going to now go wrong

[Dac02]

Hi
Fitted another egr vavle to it and made no difference, car ran ok at driving speed but as soon as idle, eml light back on and limp mode.
Next to renew the electovalve things or will be better to blank off, does thisput the emllight back on.
Thanks

[Dac02]

Ok egr blanked off and still no change, so i unplugged the electrical connector to the vacuum valve on the right side as you look at it and no eml light, plug it back in and eml light and limp mode within seconds.
So think the problem is with that valve as Gibbo2286 suggested.
Going to try a second hand 1 from the bay, if no change have to shell out for a new 1.
Thanks for advice all