I just replaced the fuel filter on my 1990 E30 318i (it has one external filter below the left rear passenger footwell), but now the pump is "buzzing", something it never did before. The arrow on the filter points towards the pipe leading to the injectors so I assume I have put it in the right way round?

Is the pump on its way out or should I just ignore it?

The other thing is, how do I know if the fuel regulator is still OK? I ask because when I replaced the fuel filter, I realised after starting the engine that I'd forgotten the clamp on the pipe coming from the tank. I switched off and pulled off the rubber pipe from the filter and did I get sprayed with petrol i.e. which sprayed from the "tank end" of the filter! I couldn't see for about 15 minutes! That means that there is tremendous presure coming back from the injectors, through the filter i.e. against the direction of the arrow on the filter casing back to the fuel pump and which I wouldn't have though can be doing the fuel pump any good i.e. trying to pump fuel against high pressure? Admittedly, this was immediately after switching off the engine; in the past when I've replaced filters on other cars, there is very little pressure coming back to the tank.

Can anyone give me a bit of advice. My local dealer is worse than useless.

Thanks

Dave