EGR Return pipes x351 3.0D

Black_xjd · January 10, 2020

Hi all,

Just a heads up for anybody getting a EML with an EGR code. I got a P0401 code a month ago relating to insufficient flow but after a day it went off and never returned. No running issues at all. The other day it came back on so I began to speculate if there was an underlying issue and if there were any potential blockages that were building up. The next day no light again? I know the EGRs are tucked down the sides of the engine meaning that they are fiddly to get out but I wanted to at least do some sort of inspection..

I decided there must be some blockage in the upstream part of the EGRs cycle leading to the inlet and I had a problem with this on an Audi one time so I took off the return pipes (one each bank) that come from the EGR into the box just before the inlet in the centre top of the engine bay. With these off it gave me access to have a partial look into the EGR units themselves (which were lined with soot but looked clear/ clean enough to have no worries).

Both ends of these pipes I took off have a piece that protrudes into the housing they bolt to and appear to touch/ join up inside this housing as they are opposite each other. Each one has four holes on the end like as though these holes are used to let the gasses out into the inlet again. These were clogged up. With a scrap and some brake cleaner and a few rags they were cleared up and fully functional.

No light as of yet but just incase there are any issues try this first, two 8mm bolts on the EGR valve end with the gasket fixed onto the pipe so no lining up, one 8mm bolt in the middle which holds it in place and two I think T25 star key screws on the plastic housing at the top. A bit tight but a fairly quick and straightforward job, don’t drop any bolts so be careful, take out/clean/place back the big o ring on the plastic housing end and don’t worry if the end against the housing doesn’t fully go in, it’s the o ring so tighten the top end in first then the EGR end after so it lines in, once the pipe is in place.

Car feels a bit better after this and I suspect the EGR temp sensors set the code due to rising temps in the EGR due to a back up of gasses. Sorry for the lack of pictures as the light was going out and I was on the driveway but this picture shows what it is like after 95000 mls.

The top end of the pipe totally clogged and the bottom (EGR end) ok. Definitely worth doing especially where they are and the design they consist of, I don’t think barely any gasses we’re getting through at times.

Thanks for reading