Intercooler Outlet pipe, EGR and DPF I did ask this question on the DPF thread so mods please close if you think this is a problem but that thread is a bit long and not sure how much activity it gets.
...anyway, i have been having intermittent DPF issues over the past year and i know in general that it's down to not doing enough motorway driving but there have also been cases where i've done a long journey then towards the end of it the DPF light comes on. I then have to continue for an extra 15 mins to clear it. In some cases light light has not cleared and the MIL light comes on.
Before i booked it in for a regen, i decided to clean the EGR valve again and as i started to remove some of the pipework i noticed that the pipe from the intercooler out to the throttle valve had a large break in it and someone had tried to seal it up with a screw clamp. The break must have got worse as it was now quite large and you could easily slide a 50c coin into it.
Anyway to cut a long story, the EGR was still prettly clean from the last time i did it so i reassembled everything and replaced the pipe with a new one @120$ from nissan the car seems to run fine and hopefuly the regen will clear the current dpf issue.
Is it likely that the hole in the pipe could contribute to failed dpf burns as i know the exhaust gasses contribute to the temperature increase needed to do a dpf burn however i can't seem to work out the flow of gasses through the EGR valve to support this.
Re: Intercooler Outlet pipe, EGR and DPF John I know this is an old post now and you would have moved on. The EGR valve when open is used by manufacturer to reduce cylinder temp which in turn reduce, in short, emissions. So when a regen is happening I would suggest EGR is closed to assist in raising cylinder temp along with a longer fuel injection mode.
2009 XTrail TS Diesel Auto
TBH as per my other post in another thread i have moved on quite a bit since this. I ended up replacing a few pipes that had splits as well as the egr valve as it started to stick.
Regens seem to be fine for now although the soot mass never seems to get to 0. I actually think this is due to an aftermarket DPF and differences in the baseline differential pressure causing the dpf sensor to read higher that it should. I guess i will never know unless i replace the dpf again and the soot mass reads 0.
I tend to nurse the car a bit at the mo, so i watch the soot mass go up and then make sure i do a motorway run to bring it down. I usually go from around 30g to 10 after a regen which seems to be fine.