M59 uneven running at low revs

[Ed D]

Hi
I have an 07  HDI 90 Peugot MPV with 140k on the clock.
Following advice I tried running it at high revs for a few miles the other day at the end of a long trip, as it often just gets short journeys. After that it ran well when over 2000 RPM but is lumpy / uneven when at low revs. After a couple of weeks it started running normally, and well.
Later I tried the high rev routine again and it was followed by the same problem of uneven running.
I have looked around the forum expecting to find this is a known problem and perhaps even something I can do to get the car back to smooth running quickly. So far I've not found anything hence posting this and hoping to get some learning and advice.
OK so I won't bother trying the high revs routine again and am hoping that it will return to good running  in  time.
Thanks

[Ed D]

After more reading here I guess this is something to do with the EGR. Fixing that sounds difficult especially if it requires some remapping of firmware (beyond me and my local garage).
I'll hope it sorts itself out. Mmmm

[brodfather11]

The EGR and the air flow sensor are related .

Sometimes by disconnecting the air flow sensor it cures problems like yours. It sits in the air intake pipe.

Just unplug it and see if it makes any difference if not nothing lost just plug it back in .

[Kieron G]

I'm having the same problem with 2.0 hdi fitted in my sister's Dispatch.
It runs fine when warmed up but is almost un driveable when cold until engine gets to revs where turbo kicks in there is almost no acceleration.
Was thinking to use an additive in the diesel I hadn't considered EGR.
I read on another forum that Wynns Formula Gold sorted out a C5 2.0 Hdi so might try that first

[Ed D]

The EGR and the air flow sensor are related .

Sometimes by disconnecting the air flow sensor it cures problems like yours. It sits in the air intake pipe.

Just unplug it and see if it makes any difference if not nothing lost just plug it back in .

Thanks, 
I will give it a try, although right now the issue seems to have almost sorted itself so I will wait a bit until I have something definite to fix.

[Ed D]

I'm having the same problem with 2.0 hdi fitted in my sister's Dispatch.
It runs fine when warmed up but is almost un driveable  when cold until engine gets to revs where turbo kicks in there is almost no acceleration.
Was thinking to use an additive in the diesel I hadn't considered EGR.
I read on another forum that Wynns Formula Gold sorted out a C5 2.0 Hdi so might try that first

An additative was also my thought, but then I got confused by the number opf them around, hence this post.
Right now it seems to be running a lot better so I'll leave well alone but if it starts playing up I'll try the air flow sensor and then Wynns Gold
Thanks