Funny problem with Citroen Cactus

onlyroz

I've had a funny problem with my Citroen C4 Cactus these last few weeks (1.6 BlueHDi). It has been juddering and shaking in 5th gear at high speeds (55+ mph) or on hills (45+ mph) - as if I was driving in too low a gear. The dealer said that this was most likely a wheel balancing or tracking issue and so I toddled off to have this checked, and sure enough the wheel balancing was off. However, this failed to fix the problem.

And so today I drove it down to the dealer (with the car exhibiting the problem on the way), but I got a call this afternoon saying that they couldn't reproduce the issue. When I collected it I arranged to go on a drive tomorrow with one of the engineers to see if I could demonstrate it to them.

However, on my way home from the dealer today the issue appears to have disappeared. I was told that they inspected the car in the garage (including lifting it up and looking underneath) and that they took it out for a drive on a dual-carriageway A-road, but didn't see the problem. I'm now wondering if perhaps the issue was simply some blocked filters or something, and they managed to clear it just by driving it aggressively or something.

Does anyone have any ideas what's going on here? And if I can expect to see problems again going forward? The car is a July registered 15-plate, and is under warranty until next summer - so I need to make sure that this is sorted before then.

BeenThroughItAll

onlyroz wrote: »

I've had a funny problem with my Citroen C4 Cactus these last few weeks (1.6 BlueHDi). It has been juddering and shaking in 5th gear at high speeds (55+ mph) or on hills (45+ mph) - as if I was driving in too low a gear. The dealer said that this was most likely a wheel balancing or tracking issue and so I toddled off to have this checked, and sure enough the wheel balancing was off. However, this failed to fix the problem.

And so today I drove it down to the dealer (with the car exhibiting the problem on the way), but I got a call this afternoon saying that they couldn't reproduce the issue. When I collected it I arranged to go on a drive tomorrow with one of the engineers to see if I could demonstrate it to them.

However, on my way home from the dealer today the issue appears to have disappeared. I was told that they inspected the car in the garage (including lifting it up and looking underneath) and that they took it out for a drive on a dual-carriageway A-road, but didn't see the problem. I'm now wondering if perhaps the issue was simply some blocked filters or something, and they managed to clear it just by driving it aggressively or something.

Does anyone have any ideas what's going on here? And if I can expect to see problems again going forward? The car is a July registered 15-plate, and is under warranty until next summer - so I need to make sure that this is sorted before then.

If by any chance they've had the wheels off, an imbalance in one of the brake discs/hubs that happens to coincide harmonically with wheel position could be a possibility.

Had this on my first 528i, wheels where dynamically balanced, lower arm bushes new, discs checked for runout, etc... Fixed it eventually by going through one wheel at a time and turning them through 72 degrees (one wheel bolt) at a time. Found out eventually that with the right front wheel in one particular position there was no vibration at all. Weird, but marked the position and no more problem.

onlyroz

BeenThroughItAll wrote: »

If by any chance they've had the wheels off, an imbalance in one of the brake discs/hubs that happens to coincide harmonically with wheel position could be a possibility.

Had this on my first 528i, wheels where dynamically balanced, lower arm bushes new, discs checked for runout, etc... Fixed it eventually by going through one wheel at a time and turning them through 72 degrees (one wheel bolt) at a time. Found out eventually that with the right front wheel in one particular position there was no vibration at all. Weird, but marked the position and no more problem.

They would have had the wheels off presumably when I went in for the wheel balance check last week (which was at a different garage and didn't solve the problem). I'm not totally sure what, if anything, they actually did today other than give it a visual inspection and take it out for a drive.

Mr.Generous

does it feel like its loosing power?
Suspect the EGR valve every time.

onlyroz

Mr.Generous wrote: »

does it feel like its loosing power?
Suspect the EGR valve every time.

Is that something that can spontaneously fix itself?

If it makes any difference, the car has a stop-and-start system.

building_with_lego

Mr.Generous wrote: »

does it feel like its loosing power?
Suspect the EGR valve every time.

Would this be intermittent or constant? My Fiesta (1.4 TDCi) sometimes feels juddery, losing power, then it roars back into life. Mostly when I'm in 3rd but sometimes lower gears too and occasionally when cruising it'll judder before settling back down. My brother suggested the EGR but the garage couldn't find anything despite my description.

Norman_Castle

It has been juddering and shaking in 5th gear at high speeds (55+ mph) or on hills (45+ mph) - as if I was driving in too low a gear.

If it does it again change gear but keep to the same speed. If its a wheel balance or tracking problem it will be the same regardless of engine speed or gear.

neilmcl

onlyroz wrote: »

Does anyone have any ideas what's going on here? And if I can expect to see problems again going forward? The car is a July registered 15-plate, and is under warranty until next summer - so I need to make sure that this is sorted before then.

Are you sure that's not Summer 2018?

Strider590

Isn't fifth at 45mph the wrong gear?
Maybe op is taking fuel saving the opposite extreme and wasting fuel by labouring the engine?

neilmcl

Strider590 wrote: »

Isn't fifth at 45mph the wrong gear?
Maybe op is taking fuel saving the opposite extreme and wasting fuel by labouring the engine?

Not really, entirely depends on the car and it's gear ratio. I'd imagine most diesels would want to be in 5th at around that speed, I know mine does.

onlyroz

Strider590 wrote: »

Isn't fifth at 45mph the wrong gear?
Maybe op is taking fuel saving the opposite extreme and wasting fuel by labouring the engine?

The car is normally fine in 5th gear at 40mph on the flat, or 45-50mph on a hill.