[Engine] M59 Air intake box

[Wakou]

I am in the middle of trying to replace the gaskets on the "rocker cover" on my 2005 Berlingo (EJ05ZXY).
Now I have the "air-box" (is that the right name?) off. In the air inlets, and the manifold, is quite oily/dirty.
Is it safe to wash-out the airbox?
What is actually inside? Any sensitive electrical or other parts?
Is it worth doing, or needed?
The car has always only just managed to get through the MOT emissions, and I wonder if a cleaner air-intake would help?
I'll go down and get some pictures...

Here is a diagram of the part I am speaking of, it is very oily inside.

[geoff]

Good to clean and worth doing.

[Kieron G]

The thick black gunge in there is from the EGR. After spending a long time cleaning all the intake parts I blanked it off at the exhaust manifold. EGR might work on low milage engines but our dw8 was totally choked and runs a lot better now.

[Wakou]

Thank you for this! Kieron G.
Unf, most of it is over my head! What is the EGR? I vaguely remenber some kind of exhaust regurgitator thing? Can I just dispense with it ("blanked it off at the exhaust manifold") Get rid altogether (!!!???)
Does it affect emissions? Or anything? What does (did) it do?
Sorry for so many stupid questions!

[Kieron G]

There is a stainless steel pipe that runs from the exhaust manifold and recirculates some of the exhaust gas back through the engine. When I changed head gasket I had to remove the pipe to access one of the cylinder head bolts. The bolts that clamp it to the exhaust manifold wouldn't come undone so had to snap the pipe. When I had head off I ordered a universal blanking plate off ebay to fit on the manifold. EGR is supposed to reduce harmful emissions and I hear it is illegal to blank it off but I'm sure this engine will run cleaner without it in the long term as it won't get chocked up again.

[Wakou]

https://www.berlingoforum.com/user-22958.html
Thank you! I am having a similar problem getting mine off! 5mm Allen/Hex heads??? Now rounded off, of course!
But! I also saw this after reading your post and doing some google research, so gan canny!
https://www.evanshalshaw.com/blog/what-is-an-egr-valve/