2011 Polo TDI (CFWA) fault code

[DIYspanner]

Engine Management warning light is on.

The code reader has reported P0405 and P0405 P

Anyone know what the common issues for this are?

 

[Burnerman]

It means the EGR system is unhappy, probably due to it being bunged up with crap.....how is the car running?
John

 

[DIYspanner]

No running issues, the light has been on since Friday last.

Is the arrow pointing at the part to take off and clean?

http://i67.tinypic.com/2e51wg9.jpg

 

[Burnerman]

Yes, the valve is the thing arrowed, and all the ports need to be clean too.
Enjoy
John

 

[DIYspanner]

The pod I pointed to is actually a motor when I got it off, photo below!

Fiddley as hell!
The geared arm in the main body, which the gear drives, is spring loaded so presumably the valve in question is operated by the arm. I worked it against its spring and seemed to be free enough. Anyway, reassembled, the warning light stayed on for a short while then went off so presumably, the fault was cleared.

The code reader still indicates pending code so if the light stays out, do I just plug the reader in and clear the fault record?

 

[Burnerman]

Yes, clear the code so if it comes back you’ll know its current rather than historic.
John

 

[DIYspanner]

Thanks John!

Will be tinkering with the car again shortly when I change the fuel filter so will clear the logged then.

 

[DIYspanner]

Warning light is back on!

Are there any decent EGR valve aerosol spray cleaners?

 

[Belle427]

Not really, a can of carb cleaner and a toothbrush or similar is the best way. Very messy so an old washing up bowl is good for this.i

 

[DIYspanner]

Wynn's Diesel EGR Valve Cleaner?

Decent reviews at Halfords!

 

[Burnerman]

I think the only real way of testing is to look at the EGR, then add the product and check again after treatment.... only personally speaking but I find so much baked on crap in there only scraping shifts it.
Nothing to stop anyone giving it a try of course!
If these products did all they are claimed to maybe we'd see more of them?
John

 

[DIYspanner]

Any carbon dissolved off the valve will end up in the exhaust and impede flow perhaps.

As you say John, take it off and clean it manually.

 

[Burnerman]

Just to add fuel to this particular fire.....
A pal has a 67 plate mini, 2 litre diesel and he's had 2 new egrs under warranty. Mini say that any cleaner mustn't be used but of course they would!
John

 

[DIYspanner]

Can the sensors on a clogged EGR stop the engine from running?

The warning light's been on five weeks but the engine still runs fine.

I don't know if cleaning the EGR on a VW CFWA engine is feasible but if not, a genuine VW exchange replacement is around £300.

 

[Burnerman]

If the engine is performing well then I really wouldn't worry about it......maybe the EGR is jammed shut (if that's what the fault is!)
It may prove to be an issue at MOT time though.
John