c4 2.0 hdi hesitating when accelerating

[scotthollings]

Hello was wondering if anyone could please give me some advice I recently bought a c4 vts 2.0 hdi model 2005 when I bought it the turbo was not working so managed to quickly diagnose turbo vacuum solenoid at fault which I have replaced and now have turbo but have now been left with another fault where if you put your foot down it hesitates then surges a couple of times and it does this through all the gears, I suspected the egr so went to fit a blanking plate today but found out someone had already fitted one should I still suspect the egr with plate fitted or rule it out. Air filter and fuel filter have also been replaced. Oh and there are no warning lamps on or fault codes in the system. Any help would be much appreciated,thankyou.

[KP]

It could be a vacuum leak in the system to the wastegate maybe.

Has the car been services at the 20k intervals?

If so another thing to do is to flush the oil system and double change it to get the worst stuff out of it and switch it to a 10k interval.

What you need is a lexia monitoring the boost level as you drive it to see what it's doing boost wise.
Also you can then monitor the injectors and air flow sensors

[scotthollings]

Hi thankyou for the reply, I am pretty sure the vacuum hoses are ok as checked them all when diagnosing fault with vacuum solenoid but might have to double check them to be sure. The last service was 20000 ago but have just serviced it again my self may have to flush it through again like you said. Looking like I may have to invest in a lexia as I am a technician at a Ford dealership so really begrudge paying anybody else to fix my car.

[Lighty]

The Turbo copy signal is a common issue on the C4 2.0 hdi. It is a small triangular sensor on top of the turbo wast gate vacuum capsule. I think this device reads how much the waste gate moves and copy's the information electrically and sends it to the ECU.
They fail all the time on this car and also the Pug 307, due to water dripping into them from the sound deadening above the engine. There is an info rapid bulletin about them. If you search ebay you can buy it separately , as it only comes a a complete capsule from Citroen.
It causes surging at most speeds.

[scotthollings]

I had heard about the sensor on the on the turbo don't suppose you know if this would normally give a fault code, I read somewhere that if the sensor on turbo is playing up the fault should stop by unplugging maf sensor as ecu will use its own default settings or am I miss informed on this as I tried unplugging maf sensor but fault didn't change or improve at all. I recently tried cleaning the air intake temperature sensor that's located on double doser but have unfortunately made the problem worse than it was and have a fault code p0113 for air intake temperature sensor so I have either damaged the sensor cleaning it or touched on the actual fault so have got a replacement on the way should arrive Monday.

[Lighty]

Air temp sensor doesn't cause much trouble from a driving point of view, just high fuel consumption in my experience.
Not sure about the fault code , or unplugging the mad, as I haven't tried it.
Will try and find you the fault code, as we have one in the shop at the min.

[scotthollings]

Thanks much appreciated. Have also noticed that the coolant temperature Guage isn't functioning correct either it takes forever to go up two bars then it drops back down to to zero again. Another thing that isn't gonna help fuel consumption. for the cost of a coolant temp sensor may Aswell fit one of those too and just hope it's not a wiring fault. So far not having much luck with this car.

[scotthollings]

The Turbo copy signal is a common issue on the C4 2.0 hdi. It is a small triangular sensor on top of the turbo wast gate vacuum capsule. I think this device reads how much the waste gate moves and copy's the information electrically and sends it to the ECU.
They fail all the time on this car and also the Pug 307, due to water dripping into them from the sound deadening above the engine. There is an info rapid bulletin about them. If you search ebay you can buy it separately , as it only comes a a complete capsule from Citroen.
It causes surging at most speeds.

Had a bit of a result with engine management lamp coming on today with fault code p2565 turbo position copy signal which I assume is the sensor on the turbo was going to get one ordered from eBay just wondering if you know what these are like to fit is it just a case of unscrewing old one and fitting new one or is it more involved it's looking like I may have to drop the subframe to gain access. Thanks

[scotthollings]

Just to let everyone know I fitted new turbo copy sensor today acquired from eBay for £85 and thankfully has cured my fault car now driving perfect, thanks guys

[Lighty]

Good result, just fitted one to my sons C4 VTS, for the same reason.
The problem with the C4, as with the Pug 307 with this engine, is that the water drips into it from the scuttle panel and sound deadening, pretty sure there is a mod somewhere to prevent this happening.
Not an easy part to change, and very expensive for what it is.

[scotthollings]

Yeah I thought part was allot of money for what it was but I suppose there is not many people that sell the part so that's how they get away with it. I managed to get it Done in 3 hours with dropping subframe but I'm lucky enough to have access to a ramp. At least it's worked out cheaper than a new turbo.

[Trainman]

Guys,

Don't forget, there's a dedicated http://www.C4Owners.org" onclick="window.open(this.href);return false; website, and I know it's full of good stuff, which includes downloads for how to's........

Just a thought...

[R1-Mini]

I Know this is a bit late for anything to do with this Post
But thought i'd just share how i change this Actuator Sensor from the top
A lot easier than dropping the subframe
You take the wipers and plastic trim off then the plastic bar that goes from drivers to passenger side off
Jack under engine on the sump with a bit off wood and then undo the drivers side engine mount and remove
then lower the engine down as far at will go, the bottom engine mount holds it in place and stops it going to far but leave jack under the engine to be safe
Then i lay on top of the engine on a bit of carpet and stuck my arm down the back, un done the 3 screws and wiring plug and swapped it over
All in all the 1st time i did this took me about an Hour
Hope it helps in the Future Plus you should be able to do the same sort of thing on the 307 maybe