C5 3.0 Hdi V6 Hesitation/misfire At Low Revs And Torque When Outside T

[dflflack]

Hello Has anyone come accross this problem? I have had numerous diagnostic readouts done and there is never a fault registered but in the 'deep log their are numerous transient and non related faults found. The car is currently working like clockwork and is everything you would expect of the engine but when the outside air temperature is above 18C I get an occasional 'miss' when the engine revs are about 1200-1500 and the throttle opening is very light. This typically happens between 30 and 50 mph when the engine is not under load or on the overrun. The problem will probably dissapper during the winter and reemerge next summer. This is really spoiling my enjoyment of what is otherwise a superb vehicle. I know that there are very few vehicles of this type in the UK but has anyone experienced the same symptom and found a solution?

[paul.h]

Possibly not this, but there is a report on a Zaffira in Car Mechanics where occassionally the revs would momentarily drop off. It turned out the wiring from the accelerator pedal had been rubbing on a hose jubilee clip, the insulation had worn off and occassionally 2 bare wires touched the clip together to give the effect of the pedal being at the top of its travel. Repairing the wires and moving the clip fixed it.

[madmadmax]

i would start by looking at the temp sensors and the loom for them as it is temp related, also i would look at the maf as if that gos out of calibration and the ITA is saying the wrong thing then it would cause a miss fire

[dflflack]

I have had the car into my Citroen specialist garage (not a main agent) and they have done repeated diagnostics without finding any fault. Just a couple of days ago I took it to a Citroen Manin Dealer for a diagnostic and to check the firmware and they could find no fault. Furthermore they said that there were no air temperature sensors in the engine management system. This leaves me completely flumouxed. I am inclined to think it might be a marginal fault in the MAF but I could spend a lot of money 'shooting in the dark' and still not  resolve the problem. I suppose the C5 3.0 litre Hdi is a rare beast but has no one else experienced this problem?

[Parkesie]

Possible faults ive come across and heard of creating similar faults are sticking egr. Throtle body/maf dying. Sticking variable vane turbo. Have look around land rover forums as they use a very similar engine.

[paul.h]

If you look at the parts diagrams for the C5 (X7) with the 3.0hdi, they show 2 maf sensors which may have an air temp sensor in for the inlet air temp (AIT), an air temp sensor at the back of the engine (probably on the inlet ducting) part no. 1920JF (£26.29 from citroencarparts.net), and a temp sensor at the timing belt or chain end of the cylinder head part no. 1338E5 (£23.46). These all input to the engine management system. So it makes you wonder about the dealer's comments.

[dflflack]

My Garage did repeated diagnostics and in some of them an air flow outside (above and below) notification appeared in the deep log, no fault registered. I finally took the car into the garage and they pulled it apart and tested each component that might have caused the problem. Both MAF valves were OK, injectors OK, Turbos OK but the front EGR valve resistance reading was outside of parameters. The EGR valve like most Citroen parts was around £600 so it was with some trepidation that I agreed to have it replaced (cost with all the other work around (£1100). Collected the car yesterday and I think the problem is finally resolved. I cant be totally sure until the outside temperature rises into the 20's bu there was always a slight flat spot/tipping point at low revs and low load prior to the brief missfire/hesitation. This has gone and the car feels very smooth at low speed. I am keeping my fingers crossed until warmer weather arrives!!

[paul.h]

Thankyou for getting back to us and I hope the problem has now gone, especially after spending so much money and time.

 

I have included this topic in the C5 Common Problems topic under 27 on flat spots and hesitation. Whilst your car is not common, the problem could apply to other cars and it will help share your experience.

[dflflack]

Unfortunately, The EGR was NOT the problem. I spent £1100 and when the temperature rose above 18C again today the hesitation/missfire returned. I am stumped! The only other problem thrown up by the garage tests was one injector with a slightly raised resistance but the injection pattern read out was spot on. Has anyone got any idea what is causing this? Could the auto box be causing these symtoms?

Edited September 7, 2015 by dflflack

[dflflack]

Further to my problem - Citroen UK have so far been totally unhelpful regarding this issue so I posted it on their Facebook page. I got an almost immeadiate response requesting further information and my contact details - I can only live in hope that they might be more helpful this time around!

[Ciaran1602]

This will sound a little bit dismissive and I don't mean it to be so.

I had similar issues a while back with my DS4 1.6HDi. There was a very low rev hesitation, almost like the engine was in too high a gear but I was in first and so clearly that wasn't the case. Once the engine was warm it was fine but highly irritating. My local dealership in Fareham were very helpful but found no faults. After a while it promptly stopped.

Few days later my neighbour who owns an old '03 Kia Carens 2.0CRDi reported exactly the same issues, exacerbated by the old fashioned torque converter automatic 'box. We both filled up roughly the same time from local supermarket and so our only real conclusion was dodgy fuel. My car and his have been acting fine ever since.

[turbovette350]

Hi, I'm having similar problems with my 3.0 Hdi , when the engine gets warm I get hesitation when moving off and then an intermittent misfire on light throttle at town speeds. 

 

I'm living with it for the time being but T junctions and roundabouts can be scary.

[dflflack]

Still got the problem and the Citroen main agent never contacted me, not that they would have been any use anyway! I have tried Injector cleaners and switching to V-Power diesel but this had no effect./ They next step is too expensive to contemplate for such a minor fault. Taking out the injectors checking and or replacing them. I think I had better live with the problem and part exchange the car in the winter when the misfire never occurs!

Edited October 19, 2015 by dflflack

[dflflack]

Update - My garage discovered that the recall software update performed on my car in 2011 by a main agent was not completed properly and that there was a partial failure to install the 'fuel metering' module. This was corrected and the cvar feels much smother but the problem has not entirely dissapeared albeit less frequent. The temperature is now well below the threshold (18C) so I will have to wait for the Spring/summer to return to the issue, I might get a solution by the time the car is worn out!

[Rookie2]

Hi

Just a suggestion, it may help. I have a friend who runs his own MOT centre. Numerous times on cars that I owned and other customers cars, they have failed emissions test and have always appeared to be running a little lumpy.

At first I thought it was a money making racket he had when he advised that I bought a bottle of "Forte" from him and went for a 5 mile drive at high revs in third gear.

 

Now I had watched the figures on the emissions when the vehicle failed and I watched the figures when he retested it less than 30 minutes later. The difference was unbelievable, but more than that, the vehicle ran far far better afterwards. The Forte certainly cleans the CAT out and consequently probably did the same for the particulate filter.

I have since watched as more and more MOT customers have done the same thing and their cars which otherwise would have failed the MOT have passed.

 

Forte retails for about 12 quid a bottle, I have no connection to the company and have nothing to gain by recommending it, this stuff really works and is available for petrol or diesel engines. If your fuel metering has been set up wrong for a significant amount of time then perhaps a build of carbon etc is causing the problems, at 12 quid a pop it might be worth a go. Just a thought. cheers

[RobertC]

Hi, I'm experiencing exactly the same problem with my 3.0Hdi V6 Tourer for years. I don't think it's getting worse though. It hesitates in low rev, around 1500rpm at most at low power, usually when I drive the city speeds. When you are at stable rpm and then slightly push the pedal down to accelerate, it hesitates, sort of tugs once or few times, like it completely losts power for a fraction of a second. It happens only when the outside temperate is as mentioned higher, around 20 degrees. 

 

There's no sign of anything wrong in diagnostics. Recently let all injectors tested and cleaned, replaced 3, nothing has changed. I'm starting to believe it might be a software problem (I have the latest 2011 update). 

 

dflflack - did you have any success fixing this issue?

 

PS: excuse my bad english