C5 X7 2008 V6 auto judder

[c5rich]

Hi all, just noticed on my C5 X7 tourer, 2.7 V6, auto (mainly when engine is cold) when I hover around 2000rpm (just before gear change) or if I slightly press the accelerator (cruising behind someone) the engine judders a little... if I accelerate over the 2000rpm or change manually into gear I don't get it...

Nothing major, but it is annoying - any ideas?

[Stickyfinger]

Mileage ?

Citroen claim "sealed for life gearboxes", not true. If over 100k/130k have the oil in the gearbox changed. Changed in sets of 3 drains/refill and a reset of the oil counter by Lexia.

[c5rich]

Mileage ?

Citroen claim "sealed for life gearboxes", not true. If over 100k/130k have the oil in the gearbox changed. Changed in sets of 3 drains/refill and a reset of the oil counter by Lexia.

It has just over 82,000 miles....

[hattershaun]

Could be an EGR valve failing. Very common on this engine (and many other Diesel engines).
I had this with a C6 2.7HDi (same engine).
Slight hesitation on light throttle at 1750rpm.
Lexia diagnostic initially showed an 'airflow' fault.

There are two EGR valves on this engine and access to change them is 'interesting', workshop time is 4-5 hours to change each one.

[c5rich]

Could be an EGR valve failing. Very common on this engine (and many other Diesel engines).
I had this with a C6 2.7HDi (same engine).
Slight hesitation on light throttle at 1750rpm.
Lexia diagnostic initially showed an 'airflow' fault.

There are two EGR valves on this engine and access to change them is 'interesting', workshop time is 4-5 hours to change each one.

Thanks for the help.... my local main dealer said nothing came up 'on the lexia' last week (car was in for a service)....

[Old-Guy]

Could be an EGR valve failing. Very common on this engine (and many other Diesel engines).
I had this with a C6 2.7HDi (same engine).
Slight hesitation on light throttle at 1750rpm.
Lexia diagnostic initially showed an 'airflow' fault.

There are two EGR valves on this engine and access to change them is 'interesting', workshop time is 4-5 hours to change each one.

Thanks for the help.... my local main dealer said nothing came up 'on the lexia' last week (car was in for a service)....

So the 'fault' must be in your imagination - computers are always right.

Unfortunately, software is specified, designed and written by fallible human beings; and today far too little testing is done before software is released. When I started as a trainee programmer (1968), I was told to expect to spend 10% of my time writing (assembler) code, and the other 90% testing. That ratio is probably reversed today, with, I hope, the exception of avionics; triple redundancy doesn't help if the three 'separate' systems all have the same software with the same undiscovered deficiencies.