Juddering (kangarooing) At Low Speed

[bloomfield]

C5 estate, 2.0 petrol
I've been experiencing this juddering at low speed, (similar in effect to the kangarooing learners are supposed to do) but it has nothing to do with the clutch. It seems to me it's getting more pronounced and more frequent, so what I first thought was a normal feature now seems more like a fault. The juddering can happen at any time when travelling at low speed but is worses, a) soon after start, b) when going down an incline and c) when the accelerator is completely released. The juddering is a rapid switching between two states (1) the vehicle under power, driven by the engine, and (2) the braking effect when the car overuns and tries to turn the idling engine. This is why it's worse running down an incline with foot off the accelerator. It's as if some part of the control system says - the engine should be 'off' and provide braking effect - whilst some other part says - no keep the engine going. The rev counter is usually showing between 1 and 2 thousand rpm when this happens. I've noticed that the iding speed, which is normally around 800rpm, can sometime be held higher around 1300 for a few moment and I presumed it was the hydraulic system, or the like, demanding more power occasionally; that's why I thougth the effect was normal at first. But now it's hard to believe it's normal.

Has any one else experieinced an effect like this? I'm still trying book repair time at the dealer.

[truemouse]

[quote name='bloomfield' date='Aug 22 2005, 10:49 AM'] C5 estate, 2.0 petrol
I've been experiencing this juddering at low speed, (similar in effect to the kangarooing learners are supposed to do) but it has nothing to do with the clutch. It seems to me it's getting more pronounced and more frequent, so what I first thought was a normal feature now seems more like a fault. The juddering can happen at any time when travelling at low speed but is worses, a) soon after start, :o when going down an incline and c) when the accelerator is completely released. The juddering is a rapid switching between two states (1) the vehicle under power, driven by the engine, and (2) the braking effect when the car overuns and tries to turn the idling engine. This is why it's worse running down an incline with foot off the accelerator. It's as if some part of the control system says - the engine should be 'off' and provide braking effect - whilst some other part says - no keep the engine going. The rev counter is usually showing between 1 and 2 thousand rpm when this happens. I've noticed that the iding speed, which is normally around 800rpm, can sometime be held higher around 1300 for a few moment and I presumed it was the hydraulic system, or the like, demanding more power occasionally; that's why I thougth the effect was normal at first. But now it's hard to believe it's normal.

Has any one else experieinced an effect like this? I'm still trying book repair time at the dealer. [/quote]
Sounds to me like you're trying to treat the poor ole C5 like a Land Rover Defender with 'Descent Control'. Used to do that with my '96 AX back in the day, only because I had just passed my off-road test with the army. Stopped shortly after when the mechanic on Rhein Main airbase went ballistic, told me to go see the Frankfurt Citroen dealer, who went ballistisch, (Ballistic only with a German accent.)

Chances are you've confused the crap out of your ECU.

Best thing to do is change gear, or change your gearbox (Like automatic?)

"Learn to drive in a stick-shift, forget in an Automatic."

[aksMS]

hi. im from malaysia. got me a C5 petrol 2.0 automatic. im not sure wether that "juddering" is the same problem as mine. mileage is about 150,000+ miles. it has been serviced by the authourized dealer (on schedule) since i bought it 3 years ago. it happened every once in a while. it begin after i had to cross a small flood about 2 years ago. had to do major service on the gearbox then. :( and this juddering begin....

after i start the engine, there's this vibration or juddering from the engine and the info panel shows 'ANTI-POLLUTION FAULT' and 'CATALYCTIC CONVERTER FAULT'. As I step on the gas, the car will judder even more. as i put to Drive, the engine will judder and feels heavy and no power. but, sometimes, after driving it for a while, and restart the engine, it's just dissappear. everything is back to normal. no FAULTIES. no juddering. there are also time when this thing came up, i just restart the engine and it will dissappear. i've asked the mechanic at the service center to look into this matter everytime i went for scheduled service. seems that they cannot rectify it. anyone here knows?

[truemouse]

Never thought about that one. You might have water up your pipe. (Yeah, that totally sounded innocent, right?)

Could also be moisture in the carb, and that it's just at a certain RPM that it's getting sucked into the engine?