C5 2.2 HDi - Poor Economy??

corsehf · Post by **corsehf** » 18 Feb 2009, 04:49

Hi, I have a newly acquired C5 2.2HDI SX Estate. It has got quite a few miles on it but was at the right price and had full service history.
However, I am unable to better 30.4mpg and that is with a very careful right foot. I see on this forum that i should be expecting somewhere between 40 - 50 mpg.
I have had the dreaded ESP / Anti-Pollution fault which seems to only come on when driving on the Motorway at 70 with cruise control. The car then starts to lose power.
I have had the fault codes read and the 3 that i can remember were:
Glowplug Fault; Mass Air Flow Sensor; Swirl Chamber??.
Apparently, there is a fault with the glowplugs which will not clear on the reset, as regards the swirl chamber, i am not sure where that is and whether i have the discription right.
Would any of these faults cause my poor economy, its a great car but needs to improve its economy!!
Any help gladly accepted!

DickieG · Post by **DickieG** » 18 Feb 2009, 07:28

The 2.2 HDi is not noted for its economy but then with fault codes recorded in the ECU the engine won't be running at its optimum settings. If you're getting the Anti-Pollution fault light then the car needs to have its "Eolys" fluid topped up and maybe have its particulates filter cleaned/replaced, until that is completed then I think you'll struggle to achieve optimum economy.

When you had the fault codes read/reset was it done at a Citroën dealer or was a Lexia or Proxia diagnostic tool used? The reason I ask is that quite a number of fault codes cannot be reset with generic code readers as there is a procedure which involves either turning off the ignition or totally resetting the ECU (you get up to 50 resets).

steelcityuk · Post by **steelcityuk** » 18 Feb 2009, 12:19

The swirl chamber fault sounds like the actuator is faulty that controls the swirl function on the induction system. It could be a split pipe or faulty solenoid. A vacuum gauge could point you in the right direction.

If you're lucky just the Eolys fluid will need refilling and the dosing ECU updating. At a rough guess when cruising at steady speed the car is trying to regenerate the FAP but if there's no Eolys fluid it can't and will flag a fault.

However if this doesn't fix it then the FAP filter could be ready for replacing. If it isn't attended to in reasonable time then expect that the pressure sensor could also need replacing. From others experience Citroen/Peugeot or specialist garages are the best bet for such work. I've heard several tales of people paying good money without a satisfactory outcome.

Diesels with DPFs don't take kindly to short servicing or missed intervals.

Hope that helps?

Steve.

corsehf · Post by **corsehf** » 19 Feb 2009, 00:39

Thanks for the replies so far.
I was under the impression that the Eolys fluid would bring up its own warning? Also, as it has full service history and the Eolys is topped up every 50,000 miles?, then i should be around 20,000 miles away.
The fault coded were read from an independant garage who i trust, the fault codes were cleared except for the 'glow plug' fault which is still current as i have not tackled them as they look an absolute B*****D to do!!!!!
All the other faults have cleared but it is still drinking the fuel??!!!
The car also occasionly ticks over very roughly - almost as if it was firing on 2 cylinders yet pulls ok when you drive off.
I was kind of hoping that it may be the Air Flow Meter tricking the ECU????
Does this make sense to anyone??

DickieG · Post by **DickieG** » 19 Feb 2009, 07:43

I've just taken a look through my Info Rapid's for C5's and found one that appears to fit your car quite well (is your car's RP number between 9156 - 9198?) namely poor consumption and a fault with the swirl butterfly position being inverted which requires the ECU to have a reconfiguration with Lexia/Proxia.

SWMBO bought a brand new Picasso HDi in 2002 that came complete the recorded fault in the ECU of "Glow Plugs", no matter what I tried with generic fault code equipment the fault wouldn't clear whereas Lexia did it first time by resetting the ECU rather than simply clearing the fault, a different procedure unavailable to generic equipment. At the end of the day a fault with the glow plugs is only likely to affect starting under very cold conditions so unless that is a problem you could leave that fault recorded.

steelcityuk · Post by **steelcityuk** » 19 Feb 2009, 08:16

I think you really need to have the live data read using the dealer tool. You should then be able to see what the injector correction is, this should give an insight as to where the fault lies.

If it has glowplug faults it could be the cause of the rough idle because although an HDi doesn't need them to start it uses them for a short period when starting from cold to smooth the idle.

Steve.

corsehf · Post by **corsehf** » 19 Feb 2009, 16:41

Sorry, meant to say that the rough idling appears when on a normal drive and the engine is up to temp. First sign of it is when you slow down and stop for traffic lights etc.

KevMayer · Post by **KevMayer** » 19 Feb 2009, 20:46

My C5 2.2 Hdi gives me 36 mpg pretty much however I drive it. I think the 2.2 generally gives 36 to 38 mpg. Unless you drive very carefully.

I had a problem with my airflow meter and replaced it with a unit off ebay. It performed better with the new meter.

My C5 has always been sluggish and hasn't appeared to drive like a 136 BHP engine. But, recently, while looking for an electrical fault I removed the cover from the engine ECU compartment (Above the battery towards the windscreen). I pulled the multiplugs off the ECU and removed the fuses. I generally waggled all the fuses and plugs about to try to clean up any dirty contacts and then put it all back together. Since then, the car is transformed and It pulls like a train. It generally drives much better.

I don't know which connection I managed to clean up but I obviously did the whole system a lot of good by moving about as many electrical plugs as I could.

The antipollution fault can be caused by a turbo overboost (which can be caused by a dirty turbo boost control sleeve) or a problem with the boost pressure sensor on top of the intercooler. At 70mph on cruise control the engine boost may build up to maintain speed up an incline. If the Anti pollution warning is produced as engine load picks up (like when going up a hill) then it's probably a turbo overboost thats been detected.

As far as the swirl control, I have a cable tie holding my swirl butterfly control arm in the open position. This improves throttle response below 2100 rpm. 2100 rpm being the point at which the butterflies should open.

The rough idling sounds like the injection timing is out. The timing is determined by the ECU and if it's 'out' that means that a sensor feeding info to the ECU isn't working properly. This could be airflow or boost pressure or several others.

There are lots of independent diesel specialists who could diagnose your problem. It certainly sounds like something fundamental needs a dose of looking at. I used one once, Swadlincote Diesels near Burton Upon Trent. I was impressed by what they could do. They took my C5 for a run with their computer connected to it.

steelcityuk · Post by **steelcityuk** » 20 Feb 2009, 09:33

A lexia should soon show the cause of the problem with the rough idle. Personally I doubt the timing is out. If the sensor for the cam/crank was wrong I doubt the engine would even start and then if it would, I should think that the engine management light would illuminate. As can be seen from the image I posted the ECU checks for synchronization of the cam and crank sensors if one went faulty it should be flagged. If an injector flow correction is out by more than a small amount that injector needs looking at because the ECU is trying to smooth the idle via that injector because the flywheel sensor has detected a hesitation in the engines rotation. Injector 3 in the image shown really should be investigated for correct operation.

From what you've said about cruising at 70 when the ESP fault triggers I'd be inclined to think the engine isn't overboosting unless it happens at all speeds when accelerating hard. It still sounds like a regeneration fault to me.

Steve.

mooseshaver · Post by **mooseshaver** » 21 Feb 2009, 10:26

My C5 2.2 had the Anti-pollutions and esp fault. It was casued by a fault electrovalve that low pressure on one side.
The dealer had told me it needed a new Turbo, but fortunatly for me I took it elswhere for a correct diagnosis.

dexy350 · Post by **dexy350** » 21 Feb 2009, 19:22

how recently was the fuel filter changed ?i noticed my mpg was on the way down 38mpg down to 34mpg i thought give the car a service ,even though it was supposed to have been done at a garage before i bought the car ,the fuel filter was on its last legs ,so 40 quid later new bits new fuel filter on car ,mpg went up 40mpg on a mixture of driving best ive had is 47mpg motorway driving 70mph,just worth checking these things
dexy

corsehf · Post by **corsehf** » 22 Feb 2009, 00:18

Yes, i thought of that too, especially as the air filter box was full of wet mouldy leaves!
Emptied and cleaned the housing, changed all filters: air, oil & fuel, new oil (even though the last dealer!! bodged the sump plug!!) but to no avail, fuel consumption averages out at 28mpg. Crap really as my previous cars were a Vauxhall Omega 2.2 TD Estate which averaged 42mpg and a Citroen Xantia 2.1TD which also averaged 42mpg.
The ESP / Anti pollution fault lights up whilst driving at 70mph on the motorway but will go off (eventually after a couple of days) of gentle town and countryside driving.
As i said earlier, the only fault codes showing were:
Mass Air Flow Meter
Swirl Chamber?
Fault with Glow Plugs.

I have tried to look at the glow plugs butr they are such a pain to get to and seeing as the car is starting ok i will leave that one until later unless i'm told otherwise??
The Mass Air Flow Meter looked ok when i cleaned the sludge from the filter housing but not able to check if it is ok?? - and....
The Swirl Chamber?? - not sure where that is as yet so unable to check it. Can someone point me in the right direction please??

Post by **myglaren** » 22 Feb 2009, 01:18

You might try cleaning the MAF with carburettor cleaner spray BUT be very careful, the sensor wire is delicate and very easily damaged, don't actually touch it with anything, just spray it.
If you drop it, it is dead and gone!.

You might also remove the battery for a while. This is a pretty involved procedure and while it is off it is a good idea to charge the battery at least overnight.
Best done in a garage! The driver's window should really be left open.
Switch off the ignition.
Leave the car alone for at least 15 minutes.
Disconnect the battery.
Short the battery lead terminals (not the battery terminals

) through a low resistance - a light bulb is fine, for a couple of minutes, then clamp the terminals together in a dead short for half an hour. (or overnight if charging the battery)

When refitting the battery, connect the terminals then go and have a cup of tea.
Through the driver's window, insert the spare ignition key, leave it a minute.
Lock and unlock the doors with the remote. This should reset the central locking and immobiliser. Do it too soon and it all goes haywire.
Turn the key, through the window, to "Acc" and leave it five minutes.
Start the car and let it idle for five minutes.

You will need to reset the automatic lights and windows.
The car will re-learn your driving habits which can take a few days but will be all the better for it.

Give it an "Italian Tune-Up"

One day, I will perform this procedure on my heap.

Monkeyfeet · Post by **Monkeyfeet** » 28 Mar 2009, 12:07

I know that this thread's a bit old now but...
I always see a slight increase in economy after changing all the filters.I will need to do this in a couple of weeks but for now am still seeing 42.8 mpg - light footed most of the time, mixture of short and m'way runs, some with roof box and fully laden.
Got 47mpg on the 90 mile A road (4 up, boot load of luggage) run to Norfolk last weekend though.
Whereabouts is the swirl control arm please? Would like to try that mod.
ps - some nice advice in this thread too.Ta.

corsehf · Post by **corsehf** » 29 Mar 2009, 20:42

Ok, many thanks for the replies so far.
Just as an update really, I have not managed to get at the Turbo Solenoid sensor or EGR bits & pieces as yet but have checked out most of the vacuum pipes which appear to be ok.
However, i did find a hole although not visible in the intercooler. This could not be repaired, checked with 3 repairers so am now awaiting a new replacement.
What do you think, could the intercooler be messing with the Mass air Flow Sensor and Turbo Solenoid Sensor??