Changed oil and filter yesterday on my 308 1.6 hdi 90. On David Ireland's advice I shopped around after some Total quartz ineo 5/30 C2. Couldn't get any so I used an oil recommended for Citroen/Peugeot also 5/30 low saps and C2 rating. I have always done my own servicing over the fourty years I have been driving. I did something that I have never done before and put a can of Wynns engine flush in and held it at 1500 revs for 15 mins. I let the oil drain out for a good 15 mins. after first unscrewing the filter 2 turns. Poured in new oil and changed filter, 30 miles on I checked the oil level and the oil is still clear on the dipstick, that's a first as it is usually black after a couple of minutes of running the engine. The last full tank of fuel I used (60 ltrs.) again I did something different and added 30mill. of low ash 2 stroke. The car does run smoother and when I toe it no smoke comes out the back like it did before. With it being a 90 engine it doesn't have a particle filter so low saps oil is nothing special but it runs better so I shall use the same in 6,000 miles, and am going to carry on with the 2 stroke oil mixed in with fuel. Still a slight rattle when cold but is due a cambelt change and the rattle seems to be from belt tensioner area or higher. Is there any way the cam shaft sprocket could be noisy? Is there some sort of damper on it or does it just fit directly to the cam shaft metal to metal?