I have a MKIV Golf GTi 1.8T and this morning when I started up, the petrol light came on and the petrol gauge was on the red. I put petrol in on Monday, and knew I still had fuel in there. Filled up again twice today, £15 and then another £10, but still hasnt moved from empty and light still on. Had MOT done on Saturday and service on Tuesday, and mechanic mentioned about temperature gauge going up to 90 while driving and then dropping slightly. Any advice?