I have a C4 2007 Petrol 1.4i. I had the head gasket replaced in March this year, however, there has always been an oil leak since this was done, as well as prior to it being done. I had my car back to the garage twice more since the initial replacement. Second time they said the sealant had broke, and very shortly after this the water coolant system completed drained of water which it had never done before in the prior 4 years id had the car. I put the blame for this on them. Third time they replaced the water coolant but I refuised to pay for it as I felt it was their fault and I'd had the car in 3 times within a few months. The oil leak is still there to this day. The car passed its MOT but the MOT stated that there is a severe oil leak, I then had it in to my Citroen dealer for a health check, who confirmed the same. I then took it back to Citroen again for further diagnosis, as I am in an ongoing dispute with the previous garage. Further diagnosis from Citroen states that there is a leak from the rocker cover gaskets, sump gasket and oil filter housing. They stated that the rocker cover gasket would have been removed when replacing the head gasket. I'd like to know if there is a link between the sump gasket and head gasket, and the oil filer housing and the head gasket, to ascertain further all these leaks were caused or never fixed properly whilst doing work on the head gasket. Even if there is no link between both the sump gasket \ oil filter housing and the head gasket, surely the previous garage should have picked up on these when replacing the head gasket. I'm going through a major dispute with this garage as to why the leak is still occuring, and I feel personally that it was never fixed properly. They are blatantly denying this. Any help or advice would be most welcome. Thankyou.