I am working on a peugeot 207 just now. It was a non starter. I now have it running and it has a bit of blow by. It does not affect cold starts though, i would have to say. It does not affect starting at all. And that is sitting in a cold garage for days, and not being started.
Blow by can be an indication that piston rings are worn. Depending on how severe it is. research will tell you that most cars have a little blow by.
If your car is 146 000 miles then there is a strong possibility that this is the case with your car. A compression test will let you know for certain.
I think smoke coming from exhaust can give you some clues also, and whether it would be worse or not too bad under acceleration
This is a good video to check out.
https://www.youtube.com/watch?v=4GddZqt46gg