c5 hdi

[cachaciero]

Just to give you an idea of fuel consumption on my 2001 2.2HDi Ec SE, 106K miles (inc cylinder head rebuild when cambelt failed t 70K miles).

I commute 25 miles each way on a stretch of A1 dual carriageway. For a few years I have "religiously"recorded the mpg with cruise set to 60mph over that 25mph distance, twice daily!. Of course I have to come off cruise occasionally but averaging out over 2-3 years I generally get 58-64mpg. Anything less than 52mpg is very rare and often only occurs after Ive had to disconnect the battery and the injector computer has reset. The better figures are in the summer due to less choke. Now, in Jul, I would be disappointed with less than 60mpg.

Are you sure thats mile and not kilometers????? those figures are way better than those quoted by citroen and most people with 2.2's would consider those optimistic.

The subject of 2.2 fuel consumption has gone around on this forum a few times and most would do well to get 45 on the motorway and considerably less in town or short journey motoring.

Strange but I have no choke control on my 2.2 must go and have another look maybe thats my problem.

cachaciero

[cachaciero]

hi,i have recently purchase a 2001 c5 2.2 hdi sx saloon with 76,000 mls,after reviewing the car before i bought it, i was looking foward to having a good return of miles per gallon(after having a discovery)but unfortunatly this is not the case,can anyone help with this problem as the fuel consumption is shocking to say the least[/b]

Question 1 Auto or manual?
Question 2 what distance are your average journeys?

The 2.2 is really a motorway car with everything set up right you should get around 45 (auto) maybe a little more manual.

It does not like short stop start journeys at least in my experience a collection of such journeys particularly from cold can return consumption figures of less than 25mpg.

If an auto-box try driving it manually for a few days and then see what you are getting.

cachaciero

[sixat6]

hi,it is a manual and i probably dn't do alot of miles in one go but i still think is abit heavy

[myglaren]

Do as citroenmad suggests and give it a good thrashing, it can work wonders and is the easiest and cheapest 'fix' to try first.

[cachaciero]

hi,it is a manual and i probably dn't do alot of miles in one go but i still think is abit heavy

Well by my calcs £40.00 equates to about 7.5 gallons which gives a consumption of approx 17mpg. Yes that is heavy under these situations one might expect to see clouds of black smoke out of the back but with a working FAP that may not happen in this case. I would say that there is something badly wrong, yet presumably you have no service light or other warnings that there is a problem. Would be worth getting the ECU read to see if there are any faults. A blast down the motorway might help as well. Sticking injectors keeps on coming to mind but that really is a stab in the dark.

cachaciero

[Citroenmad]

My trip computer under reads by 3-4MPG, as does our SX C5 but the 05reg over reads by the same amount. They are a guide but not to be trusted.

[sixat6]

hi,just give it a run down the motorway,ESP not functioning comes up along with anti-pollution problem.then into slow mode which i have read about,

[cachaciero]

hi,just give it a run down the motorway,ESP not functioning comes up along with anti-pollution problem.then into slow mode which i have read about,

Well that's a serious problem when it goes into limp mode.

Normally I would say go and get the ECU codes read with a Lexia but in this case I would put money on it being a problem with the vacuum control to the turbo and swirl valves.

Failure of the swirl valve control will increase the fuel consumption at the low end quite markedly, which is a problem you have.

Failure of the swirl control diaphragm will result in lack of vacuum to control the turbo which will give you overboost and LIMP mode, which is a problem you have

This subject has been well covered on this forum do a search on swirl valves and / or my name and it will throw up several references including a quick frig that can be done to verify the problem.

cachaciero

[helena]

Yes, its a manual. I too check the mpg guage against actual fuel uptake. I measure commuting MPG on Trip1 (resetting it twice daily) but run Trip2 in parallel for each tankload (ie Trip 2 reset at each tank fillup). To ensure consistent results, I always top-up by allowing the petrol pump cut-off to stop the fuel flow 3 times, and I nearly always wait until near empty (60 - 63 ltrs).
When comparing Trip2 to actual fuel uptake and miles driven it is very accuarte - to within 2-4% every time - so I judge th mpgguage to be accurate (if not "precise" due to the car computing litres/100km and then converting to mpg). All sounds a bit geeky, and yes, I have a spreadsheet too, but such records are easy to keep and readily show any trends and potential faults.
As an aside, for 4 years I used to commute weekly from Bristol to Grantham - M5, M42, M6, M69 - 150 miles. For those journeys I would regularly return 50mpg door to door with cruise on (at 65mph)where possible.
Now for commuting daily I relax at 60mph!!
My partners C4 1.6HDimpg guage is as much as 10% out (eg reading 70mpg compared with 65mg in relaity.

[KevMayer]

The clue to your exceptionally good fuel consumption may be in the name of the location where you live.

Are there any hills in Lincolnshire... apart from in Lincoln itself ?

I've looked around the net for clues about common rail diesel performance and it looks like it is most important to make sure your injectors are clean. Using inferior fuel may cause deposits to build up. Could the Eolys oil in a 2.2 be an issue here.

There are a few companies who will refurb your injectors. There are videos on YouTube which show before and after leak off tests. Excessive leak off means a partially blocked injector nozzle. It would be interesting to see leak off results for the 2.2 which is the subject of this post.

I've just put a diesel injector cleaner sollution through my 2.2 and, I do believe it is now running smoother and has a little more perk in its response. The economy looks slightly better too. I did this because lately I have been getting very rough tickover to the extent that it even cut out sometimes. I've changed the MAF but still had a lumpy tickover. I was on the verge of contacting a local firm to get my injectors refurbed but tried a cleaning sollution first. My tickover feels nice and smooth now.

[KevMayer]

Any news on this one?

[sixat6]

hi,i took it back to garage i had it from and they had it look and said it was faulty injectors so replaced three of them,got on motorway on saturday morning 3 miles in same problem again,i e-mailed all imformation everyone gave me on this site but they didn't think that was the problem.they have got it back again,

[Citroenmad]

I guess replacing three injectors was not a cheap operation, are they not £250 each??

[cachaciero]

hi,i took it back to garage i had it from and they had it look and said it was faulty injectors so replaced three of them,got on motorway on saturday morning 3 miles in same problem again,i e-mailed all imformation everyone gave me on this site but they didn't think that was the problem.they have got it back again,

A trawl through this site and others would leave you with the strong impression that most garages don't really have a clue about the C5 and the 2.2 in particular, so unless you are lucky you could be in for a fair bit of to'ing and fro'ing before they get to discover what the real fault is which will be what I have already told you and which apparently they have discounted without even doing any basic checks, I would suggest that you print out the relevant bits of the following and tell them to check it before they do anything else.

http://www.frenchcarforum.co.uk/forum/v ... highlight=

cachaciero

[sixat6]

hi cachaciero,thanks for your input,there mechanic says there's a problem with the injector relay so he has changed it and he says it's fine now.his diagnostic tool picked the fault up.