Hi my tyre pressure light came on on my bmw 1series this morning and I carries on driving. When I left work this evening it was was making a loud flapping noise and sounded like a motorbike by the time I hit 15 mph. I stopped to fill up on air and the tyres looked fine not soft at all. I filled them to 26 but one of them wouldn't accept the air for some reason and the noise is still there....any ideas?