2011 Vauxhall Astra • 8,500 miles

I have a Vauxhall Astra Excite 1.4 2011 car. I have been noticing that when I fill up with
unleaded petrol the fuel level flucuates. The fuel gauge was on the red yesterday I filled up
£11.00 of petrol. The fuel guage showed that I had just under a 1/4 tank. I drove a mile
down the road and parked in Tesco Car Park. When I was leaving I did not see a large pot
hole which the front wheels dipped into. I noticed a minute after that the fuel gauge had
jumped to just under the red refuel level which really annoyed considering I had only just
driven a mile from the petrol station. Can you tell me whether this is a common problem
and whether I should bring the car to the Vauxhall Service Centre to be l be looked at.
August 2, 2012.

It sounds like the sender unit in the tank may have failed. You need this verifed before replacing it.