C5 2.2 'turbo lag' ?

[wideboyno1]

Hi all,

Occasional lurker but first time poster! Have done a quick search but can't seem to find the exact scenario i'm experiencing.
Got a '53' plate 2.2 Vtr that is otherwise perfect and really looked after with very low mileage but has an annoying problem at low revs.Basically until it reaches 2k it suffers from what feels like extreme turbo lag,with fairly slow pick-up but as soon as it goes past this you get a really nice shove in the back and it takes off like a rocket (compared to the 2.0 anyway!) If you bear this in mind it drives beautifully but i do occasionally forget and have gone for gaps a few times to find theres no power,much to other peoples annoyance! I don't really drive foot to the floor anyway but if you do and keep the revs up you wouldn't know there was anything wrong.It is spoiling what is (dare i say it!) so far the best c5 i have ever owned.
There are no warning messages about particle filter etc on the dash and according to the last owner this has recently been taken off,cleaned,and eolys topped up.At the time it was connected up to computer and there were no associated error codes.However,when i took it to my local inde the other day he said that his computer indicated a 'Particle system fail' message.This i believe is unusual as it is normally a 'fault' as opposed to a 'fail' if you get what i mean.His suggestion was to get it de-fapped and it is booked in for Fri to maybe get the ball rolling but obviously i would rather save the few hundred quid it's going to cost if the problem lies elsewhere.I originally thought it may be a problem with the egr valve after some reading up but he hasn't looked at it as he believes its got nothing to do with it.Fuel economy isn't as good as the 2.0 but i wasn't expecting that anyway and there are no large amounts of smoke coming out the the exhaust so he may be right? It's a very low mileage car for its age and has been used very little over the last few years,in fact when it was took in for mot last month it had only done 321 miles since the last one! i have given it a bit of stick to try and clear any blockage anywhere but it's not really improved at all.Was fun doing it though!
I should just add that after coming back from holiday and it being left for a week,when i started it i noticed VERY briefly a message on the display about esp/asr fault but it was gone before i really took any notice and hasn't come back since.I put this down to battery voltage after it sitting for a while as i know full well what gremlins this can cause having owned a very fussy '05' 1.6 that didn't settle down until it had a brand new one but obviously you guys know a LOT more than me!
Any advice would be really appreciated as i plan on keeping this car due to the vast amounts of money and work that have been done to it before i got it and although good as it is i know it's not quite right.Hopefully something simple but having owned many Xantias/C5s over the years i'm betting not!

Cheers,
Paul

[oneday]

hi what area are you in and is any members close to you that can do a lexia sesion for you

[djadams]

At a guess a sticky EGR valve or sticky/damaged variable turbo - one way or another it sounds like it's not generating boost at low engine speeds. That's not based on specific C5 experience, just general knowledge. Using a diagnostic tool to read the boost pressure while driving, or temporarily plumbing in a boost gauge could confirm that this is why the performance is poor - you'd then need to find out whether the lack of boost is caused by an EGR or turbo fault.

Either would cause increased black smoke at low engine speed/high load but that would only appear as the DPF (particle filter) filling faster, no smoke would be visible out the back because that's what the filter is for.

I don't think removing the filter will fix those performance symptoms, it'd just make any smoke that goes with them more visible. If the performance was OK at low engine speeds (low exhaust flow rate) but poor at higher engine speeds (higher exhaust flow rate) then cat or DPF damage causing high back pressure could be the cause, but not if it's the other way round.

Basically, as I spend my working life developing future engines for good performance and low emissions I'm rather prejudiced against removing emissions reduction kit generally (cos it undoes all our good work), though I know a lot of people do it.

[wideboyno1]

Thanks for the quick replies.
I'm in the Walsall area so any members with a Lexia who could help would be ideal and of course would pay for their time.
Dj,i'm also inclined to agree about it being related to the egr valve but only being able to do a basic oil/filter change etc i'm not about to go arguing with my local inde who i use all the time! I too can't really see how getting rid of the dpf system would help with this particular problem but it was something i was looking to be doing eventually anyway but not as soon as buying it.He did talk to me about variable turbos and how the fins don't allign as they should because of build up but said would be surprised if this was the cause.Have got a citroen service centre about 10 mins away and was thinking of taking round but to be honest all they are going to do is hook it up to their computer and ask me to pay them a large amount of money for little work.May just have to bite the bullet though as the car really is worth it.
Cheers again.

[oneday]

look in the supersticky on the main board index it will tell you where all the lexia owners are

[Monkeyfeet]

Hi Wideboyno1. Just a thought before you go splashing out: (Apologies if you already done this)

Have you checked the swirl valve operation? It's easy to do. You'll need to find the small ball joint operating a lever on the rhs of the cylinder head ( as you face the car, looking onto the engine) With someone operating the throttle you should see the lever move (back towards the bulkhead, I think) when the revs get to 2200/ 2300 rpm. If its all the way forwards all the time the motor makes no power at all at low revs. Mind you this should show itself when trying to pull smartly away from a junction ('cos it won't!)
Anyway, takes only 1minute to check so got to be worth a look.

[djadams]

Good point - had forgotten they had variable swirl. That could conceivably cause issues so yes, well worth a check.

[Monkeyfeet]

Don't quote me which way the lever moves, just that you need to tie it down to the low rpm position. From a picture I took it looks like it should be tied towards the bulkhead though......

[wideboyno1]

Slight update......
Went to Citroen and they of course did the predictable.."£60 for an hours labour and computer check then we MAY know whats going on" !
A quick trip up to my inde to mention the particle filter may not be the way forward followed with him insisting it MUST be the cause and to get it de-fapped,the specific message being 'diesel additive fail'.His thoughts were that the ecu controlling the system may have failed.It is going into a place in Bham tomorrow morning for an initial assesment for dpf removal and flash.Maybe their computer may throw up something different.Was going to get it done eventually but not quite yet especially as it has very recently had a new dpf and eolys top-up.Seems criminal to smash the guts out of such an expensive part.
Not tried looking yet for the lever Monkeyfeet kindly pointed out but will try my best in the light tomorrow to have a nose round.
Cheers again all.

[Monkeyfeet]

I loved smashing the guts out of the dpf, a pleasure I'd heart-fully recommend to any dpf owners. However I think you're right not to want to touch it at the mo' as it's been recently changed and topped up. But I've just reread the posts - has it definitely been replaced and fluid topped or just cleaned as you say in your initial post please?
I you do want to de-fap you could diy for next to no dosh, but get in some advice first ( you need to modify the ecu slightly)

[wideboyno1]

Right...bit the bullet.
Looks like the dpf hadn't been renewed,just cleaned and replaced.The computer at the remapping place threw up 3 codes..2 relating to the additive sytem and one concerning the egr valve.His box of tricks even told him that the car had tried to regen 5 times in the last 300 or so miles so was of the opinion that the particle filter was blocked.He also showed me the error messages that should have at some stage come on the multifunction display but this must have been with the previous owner as i've seen nothing.
Anyway,whole bloomin lot took off now and engine remapped so hopefully no more trouble from that.He also blanked off the egr valve too.He was originally going to clean it but said it had 'seized' i think.The result is that i've now got lots of low down power and torque and i know people have said it before but it really does feel like a different car.Must be looking like a new car too cos i was talking to another customer while waiting for final checks to be done and he offered to buy it off me there and then!
So for now (fingers crossed!) very happy.The only thing that slighty concerns me now is that i can hear the turbo spinning up virtually as soon as you touch the throttle.I assume this is because of the remap but am wondering whether this is going to mean premature failure or damage to it.I only ask as all the 2.0 c5s i've owned your couldn't hear it untii 2 to 2.5k at all.

[djadams]

Cool, so in all probability the DPF was actually fine, but was continually filling up with the smoke from the EGR fault, hence it having to try to regen more often than it thought it should have to and so on. Either way sounds like the DPF isn't going to need a regen any time soon(!) and blanking the EGR valve will have "fixed" the actual problem... Of course, the NOx emissions (smog, acid rain) are now through the roof, but apart from that all's good...

[wideboyno1]

Know what you're saying about the emmisions etc but if i'm perfectly honest i don't really care! Not politically correct i know but i suspect that the government will actually be more concerned than i am and only then as they are losing out on money which they could be charging me for a higher tax rate due to pollutants.
As for the original problem,i still can't believe how much a of difference there now is..these dpfs and egr valves really are the work of the devil! Still slightly concerned about overworking the turbo now the ecu has been remapped but have been reassured by the mapping place (well they would i suppose) and local inde that although audiblly working harder it should still be well within safe tolerances.Fingers crossed.