C5 2.2 Hdi Slight Shudder On Medium Acceleration - Drive Shaft U J

[Guest Old Mosher]

Hi Everyone. My C5 2.2 Hdi auto has a slight shudder on mid acceleration. Its smoove at very gental accelaration and if you give it a boot full. I also can't get past 36mpg avrige, no mater how I drive it even on cruse controle. :unsure:

[Guest mechcanico lee]

Can you get it code tested and look at data parameters , could be an egr valve bleeding in gases, you could guess at allsorts of things.

 

A good man with decent scan hardware should be able to identify the problem , diagnose properly and not waste money guessing at this and that .

[Guest Old Mosher]

I had that done and the chap that did it said the EGR valve was working OK :unsure:

[Guest mechcanico lee]

The man who looked at it is good and comes well recomended?? so next look at swirl flaps working ? injector correction factors within limits ? fuel pressure and high pressure rail monitoring all good , inlet manifold dozer flaps working as they should ( had a fault on my 607 2.2 hdi with the dozer unit ) some of the items like dozer and egr can be isolated by plugging the vaccum source off and then see how fuel consumption goes.

 

Like i say you need a good man .

 

Lee

[Guest Old Mosher]

Yes He's good. The only anomaly he found was the second oxygen probe on the exhaust on the probe had flagged up as a fault, but at the time it was working OK. Also he spotted a slight whistle from the turbo, but again it was working. I did however find a rusty flange nut in the under tray M6 or M8 I cant remember. Could that be a manifold or turbo nut and could it be blowing rather than a whistle?

[Guest mechcanico lee]

not sure about the oxygen probe thing ....sounds more like a petrol termanology, could it be the catalyst temp probes ?? does it have a dpf on that year ?

the nut you mention could be a flange nut or exhaust manifold to cyl head nuts , does it sound blowy when you accelerate ?

[Guest Old Mosher]

I blanked off the EGR valve= still the same. :(

[Guest mechcanico lee]

Does it have a dozer unit ....were the boost hoses go into the inlet manifold there is two of them controled by two butterflys.

 

One hose comes from the intercooler (cool charge air) the other is a heated supply bypassing the intercooler (for emmission shite on start up )i am not sure on the c5 but my pug 607 has this, if its only got the one hose to the inlet it makes it easier.

 

The butterflys are controlled by vaccum actuators, if you take bothof the big hoses off and look in the openings you will see with engine switched off , 1 butterfly is open and the other is closed , find the small vac pipes to the butterflys and blank them up with ball bearings if you have some (small bolts will do if not ).

 

This will rule out the butterflys doing mad things when running on the road , my 607 had a fault with the control solenoid to the intercooler butterfly and was shutting it partially making the car miss and shake also white smoke somewhat on the road .

 

Sometimes you just have to rule out things and move on with the diagnosis, all these emmission related stuff........ dozers, egr , manifold flaps are a pain in the arse on all cars.....the engine doesnt need them to just to keep the euro regulation be kind to moths squad happy....... good for the enviroment but shite for your engine .

 

Try these things and report back

[Guest Old Mosher]

Cool! I'll look at that. It has the two hoses I think.

[Guest Old Mosher]

If you haven't hit it on the head your certainly in the right ball park :) OK so with the engine off, remove cover, hose clips, hoses and vacuum pipes. The valve for the inter-cooler hose is normally open and the valve for the direct hose is normally closed. I connected a clean vacuum pipe to the valves and sucked the air out. They both work OK but I couldn't help noticing the diaphragm actuator support bracket is cracked and looking rather flimsy on the non inter-cooled valve.

I ran the engine at idle (which was still hot from the drive home) and checked the vacuum lines. No vacuum for the non inter-cooled valve but a small amount of vacuum could be detected on the inter-cooled valve pipe. I connected it to the valve but it wasn't sufficient to move the valve flap, not at tick over anyway.

I put the hoses back on and plugged the vacuum pipes with cap head bolts. took it for a drive an it feels much better but not quite fixed. Mpg still looks naff though. Also I noted a surprising amount of sutty looking stuff stuck to the middle of the underside of the top cover. Couldn't see where from though :(

I can see I need so replace the non inter-cooled valve and the vacuum solenoid for the inter-cooler line, but what else should I test to up the mpg.

[Guest mechcanico lee]

Ok we getting somewhere now, dont worry to much about these butterflys, you could leave them blanked up and all will be fine (my 607 has been blanked for at least 6000 miles and no faults. The intercooled side being open is the one that matters as this will keep the air charge cool. The other one (non cooled side )operates from cold ,this flap opens and the cooled side closes ....its all to do with emmissions on warm up (engines better without it), the later cars with electronic dozers you carnt do this man. light will flag

 

It is better though to blank the vaccum off at the control solenoids end , follow the two vaccum pipes up from the dozer unit , i think they go up to the nearside corner of bulkhead , on the solenoids there is a vaccum supply and the other pipes are the ones going off to the dozer.

 

Blank the supply pipe off .......why ? the acctual solenoids can leak the vaccum away when they are not being comanded and the whole vaccum system brakes servo and vaccum to the turbo wastegate can go low........low vaccum = low pull on the wastegate.

 

When i did this on my 607 the brakes went much better and the power of the car improved loads(better operation of wastegate, fuel mpg better the lot :) :) just be sure to blank the correct valves , in total ther will be 4

 

 

1 dozer flap heated side

2 dozer flap intercooler side

3 egr valve

4 turbo wastegate control

 

The sooty looking shite on the cover .......could this be leaking injector seals (compression blowing out ) very often the dozer unit spindles can leak and you get oil residue being forced out or split turbo hoses .....though you should be able to hear it blowing the air off, just have a good inspection .

 

Hope this helps somemore , my one typing finger got blister now :(

[Old Mosher]

Sorry for the delay but I seem to have had my account accidentally deleted :rolleyes:

Still I'm back on line and itching to pick this up as I have checked everything listed and still have the problem. I have a new MAF censure on order so ill try that next. :)

[Randombloke]

You could try cleaning the MAF sensor by squirting it with carburettor cleaner spray then compressed air, but don't touch it or you will probably damage it.

 

Other issues with fuel consumption - check brake drag - older PSA cars are notorious for this. It's usually the front calipers.

 

Double check for leaks in the inlet side of the system - any leak will reduce performance and increase fuel economy.

[Old Mosher]

OK, Ive a few more peaces to add to this puzzle.

I fitted a new MAF censure and it made a slight improvement to the shuddering, but it is still there. The MPG didn't improve at all but I did spot something odd today. If leave the sport mode switched on I get almost 10MPG more?

another odd thing I noticed the other day is that the gearbox hesitates on its up shift if I accelerate hard round a roundabout. Low auto fluid???? :unsure:

[taximattcy]

Hi Everyone. My C5 2.2 Hdi auto has a slight shudder on mid acceleration. Its smoove at very gental accelaration and if you give it a boot full. I also can't get past 36mpg avrige, no mater how I drive it even on cruse controle. http://www.citroen-owners-club.co.uk/citroen/public/style_emoticons/default/unsure.gif

you found the problem with your car because i have the same problem if you can help me please   taximattcy@hotmail.com

Edited October 6, 2015 by taximattcy

[taximattcy]

Hi Everyone. My C5 2.2 Hdi auto has a slight shudder on mid acceleration. Its smoove at very gental accelaration and if you give it a boot full. I also can't get past 36mpg avrige, no mater how I drive it even on cruse controle. http://www.citroen-owners-club.co.uk/citroen/public/style_emoticons/default/unsure.gif

you can tell me what problem was?

[Randombloke]

I've got this problem on C5 tourer and there are no codes, looks like the drive shaft UJs are worn.

 

It's being done now will report back.

[Randombloke]

Report back:

 

The o/s drive shaft UJs were badly worn, the drive shaft has been replaced and the problem is fixed.