Peugeot 207 blue smoke

i am no expert, but to me your engine has 2 problems. the first problem sounds like one or more of your engine bearings run dry of oil when you stop the engine and let it cool down. i agree with your garage a new filter and a change of oil will help this a little, you may also consider putting an oil additive in as well. one of the thick sticky ones that come in a small can. these are designed to help higher milage engines last longer.

your second problem the blue smoke is that your engine burns a bit of oil when it starts. there are only 2 reasons i know of why this will happen, either your oil control rings on the pistons are sticking or worn, or what is more likely is your valve guides let a little oil drain from the rocker box into the cylinders when the engine cools down, and as you start this is burned off by the engine.

get a mechanic to do a cylinder oil test. this only means taking the spark plugs out and adding a little oil down the plug hole, then starting and testing, then repeating the test on all 4 plugs. this will show him if its the head or the block. if its the head its not such a big job, but if its the block consider a replacement engine. why do l say that? well this type of problem only usualy occurs on high milage engines, or ones that havnt been maintained correctly, or just plain bad luck.

sorry for the bad news.... but do change the oil and filter first...