Bit of an odd one, and I'm probably being a bit paranoid.
My car is a Ford Focus, 2009, automatic. I'm probably very paranoid about it. It's a diesel, and I realise diesels make different noises than petrol cars. It recently had to have the alternator replaced too, and it makes a bit of a "whooshing" sound when accelerating hard, which I believe indicates an exhaust leak. And, when setting off from cold, I can feel a bit of a "bump" after a moment, which is a one-off (though again, whenever setting off from cold/standing, typically as I leave for work or as I set off home).
First off, how worried should I be about these problems? And how expensive are they to fix?
Secondly, the one that just happened. Was waiting to turn right into a street. The way becomes clear, I go. As I start to move, the car makes a bit of a "jump" - though it did not suddenly move forward. It was more like I ran over something like a rock. From there, it would not change gear whilst I took the corner.
I parked up in the street and turned the engine off and on again, and it's worked fine since (though note that I only had about 15 minutes drive from there, but a lot of it at speed).
Is this a sign of slipping gears, and should I get my transmission fluid replaced?
EDIT - should be noted that no warning lights came on.