Strange Rough Running At ~35 & 72 Mph Only!

[Guest JPWILL7675]

Hi - I have a C5 2.2HDi Auto estate (2001) Its a great car put with a strange problem. The car runs well at all speeds but under constant throttle either at about 35mph or 72 mph it runs roughly. its more "lumpy" at 35 mph at 72mph you can just feel a slight hesitancy or a misfire.

 

The car has been properly serviced and has a new cambelt fitted around 80k miles. It now has 90k miles.

 

The car also runs roughly on start-up especially during the last winter. It also used to blow white/grey smoke on acceleration when cold. I had new injector seals fitted which seems to have solved the smoke problem.

 

I wondered if anyone else has come accross this issue and perhaps knows the solution.

 

 

Thanks for any help,

 

Regards, Jim

[paul.h]

This may not be your problem, but on the 2.2 hdi there is an actuator at the gearbox end of the cylinder head with a plastic cup on the end of a long rod which breaks. It is called a diaphragm and controls the swirl plates. It is a common failure and there are numerous posts about it.

[Randombloke]

This may not be your problem, but on the 2.2 hdi there is an actuator at the gearbox end of the cylinder head with a plastic cup on the end of a long rod which breaks. It is called a diaphragm and controls the swirl plates. It is a common failure and there are numerous posts about it.

 

When it breaks it usually leads to an "Anti Pollution" fault warning.

[paul.h]

'usually leads to an "Anti Pollution" fault warning'

 

This did not happen when mine broke, unless it was just before I lifted the bonnet. However, previous few trips, I had been getting nearly 60 mpg and once replaced, it was back to 50 ish.

[Guest JPWILL7675]

Thanks very much for the comments and suggestions. I took the car for a run up to Bristol yesterday. Actually the problem (of rough running ) occurs at about 2200 -2400 rpm when on constant throttle. Does a valve or switch operate around that rpm?

 

I think I may have to take it in to a garage before it gets worse or breaks down. Are there any good independent Citroen specialists in Dorset?

 

Appreciate any further advice.

 

Regards,

 

Jim