Citroen C5 X7, Annoying jerking at light loads in slow moving traffic.

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Adam82
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Joined: 30 Dec 2019, 11:54

Citroen C5 X7, Annoying jerking at light loads in slow moving traffic.

Unread post by Adam82 »

Hi all,
Hope we are all enjoying the long weekend.
Over the last few months I have serviced and replaced quite a few parts but this problem and another has not gone away and it’s really annoying.
Going to try and explain as best as I can.

Ever since I’ve had the car it’s jerky in slow moving traffic and up to 30mph.
It’s as if the car is in an intermittent anti stall mode.
It doesn't matter if i'm stationary or not if the clutch is depressed, the lightest of accelerator pressure will bump the revs up to 1300, (the rpm can be lower but it’s a fixed rev). The same events happen when in any gear, I have to slip the clutch in 2nd or 3rd as it’s impossible to drive smoothly in 1st if traffic is crawling.
If I keep this up I’ll be looking at replacing the clutch at 124k. I think it’s a SAC clutch too so not looking forward to spending additional money on the tool for this.

I’ve had diagbox connected and I can see both potentiometer signals. These are moving in a smooth linear fashion with no spraddic values over the full deflection range. I also moved the pedal by hand over the ranges where light loads and reves are required. I don’t see any number jumping to random values.
I initially thought this issue was temperature related but no, if it's a cold morning or the nice warm recent weather we have had, it makes no difference.

To finish I have checked all the pipe work visually and can’t see or hear any boost leaks.

VIN: VF7**************[VIN obfuscated, can be read by forum staff]

Any ideas?
Last edited by xantia_v6 on 24 May 2020, 20:59, edited 1 time in total.
Reason: mask VIN

ed_ronayne
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Joined: 26 May 2020, 09:03

Re: Citroen C5 X7, Annoying jerking at light loads in slow moving traffic.

Unread post by ed_ronayne »

Hi Adam82

I once had a very similar issue on a Peugeot 406, 1.6 16 Valve.
Turned out to be the EGR causing the issue.

not sure of the X7 has the newer 8 valve variant of that engine

As a quick test disconnect the multiplug connector to the EGR valve at the right hand rear of the engine.
you will get an EML on the dash. but the car will drive as smooth as silk and confirm if your having the same issue.

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GiveMeABreak
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Re: Citroen C5 X7, Annoying jerking at light loads in slow moving traffic.

Unread post by GiveMeABreak »

He has the 16 valve 2.0 engine.

Peter.N.
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Re: Citroen C5 X7, Annoying jerking at light loads in slow moving traffic.

Unread post by Peter.N. »

Both of mine seem to be a little erratic at small throttle openings, especially when cold. When I got the first one I was always stalling it pulling away, in fact I still do occasionally - could be something to do with the fact that my previous car was a Merc 220 diesel, a rubbish car in many respects but I couldn't fault the engine, it would pull a house down and would pull away with no throttle at all.

I thought that was responsible for me stalling the C5 but I have noticed it is prone to cutting out if you try to accelerate at very low revs. The second one I got is not so bad but still has a tendency to stall if you are not careful. My wife seems to manage OK but she probably revs them more than me. After 10 years of driving XMs and another with 406s I have got used to not having to rev them to pull away - and I don't like wearing the clutch out.

Peter

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Adam82
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Re: Citroen C5 X7, Annoying jerking at light loads in slow moving traffic.

Unread post by Adam82 »

Thanks for the comments.
It’s a 2011 2.0 16V HDI, 163PS
I'll pull the EGR system off this weekend and give it a clean if it needs it.
I forgot to mention, I notice that the car feels lumpy when it’s doing its DPF clean. With or without cruise control.
Does anyone else experience this?
Most of the time it runs really smooth and it’s such a comfortable place to be in.

I get around 560 miles, plus minus 20 miles out of a tank. So I presume it’s running well?
My record was in my old 1.4 16V HDI C3, 627miles from full to just the reserve light.

Adam.

Peter.N.
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Re: Citroen C5 X7, Annoying jerking at light loads in slow moving traffic.

Unread post by Peter.N. »

Mine does a phominal fuel consumption, but I drive phenomenally slowly. I tend to stick to the nearside lane of the motorway but can exceed 70 mpg when you include a few speed restrictions. It averages just under 50 in the winter but nearer 60 mpg in the summer. I also live in a rural area and drive mostly there.

Peter