paul.h Posted May 23, 2016 Posted May 23, 2016 I had to replace the diaphragm on our 2004 C5 2.2 hdi when the plastic cup broke which is a common problem but the actuator part of it worked ok. When replaced, I noticed that when the engine was started the actuator arm moved, so something you could check. It was a bit awkward to replace and I have posted on it but maybe on the C8 it may not be as bad. 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. Quote
BigBruv Posted May 24, 2016 Author Posted May 24, 2016 OK.new swirl valve actuator fitted, the old one did have a split in it. New intercooler hose with the two butterfly valves on. One of the old ones didn't close properly, stared her up, swirl valve works now, stays in the up position until engine is revved and it drops until revs drop and it goes back up. Took her for a drive and still got no power. I can her the turbo spooling and if you squeeze the top hose as you rev it you can feel it expand as the turbo pushes air through, it has to be something else, I'm at a loss now. Any other ideas anyone.. Quote
BigBruv Posted May 26, 2016 Author Posted May 26, 2016 I think I have solved it. It was the map/boost sensor. On the side of the intercooler, can't say I noticed it before. The small tube leading into it was kinked restricting air flow. Cleaned it and straighted the hose and she works.It's still very sluggish under 2k revs but as I go over she is OK. Quote
Simple Posted May 26, 2016 Posted May 26, 2016 (edited) Well done. Being sluggish under 2K RPM indicates it is not related to turbo.. Ensure the pipe hasn't got a small (pin size hole) caused by the kink, wrap suspect areas with tape for testing, usually splits and holes are near the connections or where it rubs against other bodies. Ensure your diesel and air filters are good and clean, put some diesel additive to clean the injectors. Your MAF (Mass Air Flow) sensor may need cleaning. Do NOT touch the inside with any object. If you have alrady touched it with a hard object, it could be the reason for sluggishness. There is a special cleaning spray for it. You could also check the timing to ensure it is in order. Mine suffered lack of power for months and I tried everything to no avail. I suspected the timing but it took me some time until I learnt how to do it. I found the belt was slightly slack and off by one tooth. However, there is one thing that will make you feel a difference and that is; adjust the (TPS) Throttle Position Sensor.Trace the throttle cable under the bonnet, you will find it goes into a sensor in a tight area. Pull the cable (lightly) and release it few times to understand the mechanism. You will find there is a springy stopper that can be re-positioned. Pull the cable and adjust the TPS to your liking, Edited May 26, 2016 by Simple Quote
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