2004 C8 2.2Hdi Low Power Up Hills

[rfhspares]

Car starts and drives seemingly normal on the flat under low loads. If I hit a big hill or accelerate hard higher than 3000rpm I have no power,feels like it bogs down like a huge flat spot in power. no eml comes on.

Although no eml showing, a Fault code does shows on the snap-on tool p0026, intake valve control solonoid circuit range/performance bank 1.

Reading other forums I am sure the fault is either 1 of the 4 turbo boost electro valves with the vacuum hoses attached or its the swirl diaphram or plastic clip that I think breaks a lot. Can anyone tell me which 1 of the 4 turbo boost things is most likely and are they all exactly the same component and swappable?

I will try and see of the swirl diaphram is working but it looks difficult to see let alone remove.

 

Ps: the eml does come on if I disconnect the maf sensor so the eml is actually working but the fault I have is obviously not effecting something within the emissions. I also do get a message every now and again saying esp/asr not functioning but I don't know if it's related.

 

Thanks in advance

Edited January 31, 2017 by rfhspares

[Simple]

I had this problem which took me long time to find.

 

When investigating it, exclude the MAF sensor, the diesel filter and the TPS and some other cables and sensors. However, a lot of people reported cracks in the (thin) vacuum pipes, try checking all.

 

My problem (I reported in one of the posts) was wear in the plastic casing of the swirl diaphragm (to the right of the diesel filter) as a result of friction between a pipe and the case of the diaphragm.

 

It was found by accident. We noticed a hissing noise with the bonnet open and the engine on, which lasted few seconds after switching the engine off. We got a flexible plastic pipe, one side to the ear and the other trying to trace the noise source until it was located. There was no way we could have guessed it. The hole was so small to be noticed and was covered by the presence of the pipe which obscured the source and made the high frequency noise sound from somewhere else. 

 

So, if you still hear the vacuum noise after turning the engine off, try tracing it. Or it may be something else altogether!!

Edited February 1, 2017 by Simple

[paul.h]

We had a 2004 C5 2.2 hdi where the swirl diaphragm actuator plastic ball cup broke so had to replace it. This is a common problem and this is from the C5 Common Problems topic:

 

11. C5 2.2 hdi 136 hp only, swirl plate diaphragm actuator ball cup breaks.

Vacuum leak/turbo fault codes (any engine).

Located at the left end of the cylinder head. Symptoms may be loss of acceleration, engine management light, increased fuel economy. The plastic ball cup may be replaced on its own (10 mins) or the complete actuator replaced (several hours DIY), about £20 but the cup is not available separately. This topic has a few notes on how to replace the part http://www.citroen-o...ragm#entry40936

 

There is a diy fix here if not able or want to get the dealer part http://www.citroen-o...-to/#entry82945

 

I read in Car Mechanics a case where the actuator had a vacuum leak which resulted in the engine management light and limp mode and fault codes for over boost and turbo regulation fault. The slow loss of vacuum reduced it also to the turbo wastegate so turbo boost level dropped, the ecu then increased the boost control duty cycle which then deactivated the swirl control increasing the vacuum boost and tripping the EML/limp mode. These fault codes have also been reported here and it turned out to be a split in the vacuum pipe to the egr valve actuator - so any cause of a vacuum leak should be looked for before touching the turbo.

[rfhspares]

Thabks for your help. Found that the plastic ball on the swirl diaphragm valve is broken so it isn't lifting the lever at all. When I lift the lever by hand it doesn't seem to move very far and seems to seize up. Once it's up it takes a bit of force to push it back down. Maybe the reason the plastic broke.

Anyone else had problems with the lever getting tight and is it just a matter of lubricating it when it's in bits. Looks fiddly to get to with lots in the way.

Edited February 1, 2017 by rfhspares

[paul.h]

It is about 7 years since I did our C5 but from memory the lever did not move much and was easy to move over the little bit it did move. Possibly you are moving it too far so the flaps are being jammed. If you watch the rod from the diaphragm move as the engine is started and also revved, you will see how far the lever is supposed to move. If the rod does not move then you know that part of it also needs replacing, as well the plastic cup - or you have a large vacuum leak (which could be the diaphragm).

[rfhspares]

I thought it might only move this short distance but I watched the rod that isn't connected to anything and it seems to have more travel than this lever has. For the time being I have positioned the lever downwards which I think is in its open position and I have plugged the vacuum hose as I was thinking the diaphram may also be damaged and causing leakage. Have experimented a little today and it seems to be running better with it how it is but definitely not right still. I know the diaphram solenoid is broken so I have to start with this and hopefully that's all it needs.

[hugh3lf]

A good explanation of how to change the swirl valve  and a video of its operation is here:- https://www.facebook.com/groups/Eurovan2/permalink/1219527668113694/   Incidentally I got same codes using a many of the free OBD Apps - it turned out to be the MAF.

[rfhspares]

I did change my swirl valve and it made no difference for me.

I then changed a couple of the vacuum solonoids and made no difference.

I changed the maf and it worked perfectly for 2 weeks.

I changed the map sensor and still no good.

I put my old maf in and left the new map sensor in and I also played with the hot/cold throttle body flaps by taking the hoses off and moving them by hand inside the plastic housing and it's been perfect ever since.

My thoughts are that it was either the map sensor failing or the flaps inside the throttle body sticking.