Uneven Running - C5 2.0 Hdi 2005

[227duke]

Can anyone help with this issue? My Hdi runs well most of the time,

except for when the accelerator is just pressed slightly - not quite

closed throttle, not fully open - that spot which one uses to maintain

a speed, rather than increase speed. The motor will seem to 'surge' on

and off, giving a sort of (gentle) kangarooing effect. As soon as I

alter the accelerator position, either coming off the gas or gently on

the gas, the problem disappears. This is only noticeable around town -

I can't really detect it at motorway speeds. Any suggestions

appreciated - I have heard that the EGR valve may be suspect - if so,

where is this located on later C5 Hdi's (mine is a type 2, 2005 model).

[72dudes]

Can anyone help with this issue? My Hdi runs well most of the time,

except for when the accelerator is just pressed slightly - not quite

closed throttle, not fully open - that spot which one uses to maintain

a speed, rather than increase speed. The motor will seem to 'surge' on

and off, giving a sort of (gentle) kangarooing effect. As soon as I

alter the accelerator position, either coming off the gas or gently on

the gas, the problem disappears. This is only noticeable around town -

I can't really detect it at motorway speeds. Any suggestions

appreciated - I have heard that the EGR valve may be suspect - if so,

where is this located on later C5 Hdi's (mine is a type 2, 2005 model).

 

M'mm, interesting: My 2001 2.2 HDi has started to do this occasionally - most noticeable at 35-40 MPH in 4th gear, light throttle but not on overrun, so I'd be interested in opinions too.

[paul.h]

Cleaning inside the throttle body and plate with carb cleaner and a rag to remove carbon build up may help (at least it has on my previous petrol cars where idling has been poor). Maybe also check the air filter is clean.

How many miles have the cars done, could there be a worn spot on the accelerator pedal electrics ?

[72dudes]

Cleaning inside the throttle body and plate with carb cleaner and a rag to remove carbon build up may help (at least it has on my previous petrol cars where idling has been poor). Maybe also check the air filter is clean.

How many miles have the cars done, could there be a worn spot on the accelerator pedal electrics ?

 

Thanks for this - mine has done 59,000.

[Randombloke]

M'mm, interesting: My 2001 2.2 HDi has started to do this occasionally - most noticeable at 35-40 MPH in 4th gear, light throttle but not on overrun, so I'd be interested in opinions too.

 

If you have cruise control then you can use this to see if the throttle position sensor has a dead spot.

 

At the same speed and engine load but on cruise does the fault disappear?

[227duke]

This problem is found even when using cruise - again, only noticeable at town speeds. So the pedal / throttle pos sensor would appear to be guilt free...