Scott&Kerry

Just had the fuel filter replaced and now the fuel pump makes a humming sound. Took it back to the mechanic and he said that’s normal once you change the filter because the fuel flow is no longer restricted. Does that sound right?

Serndipity

What your mechanic said is not true.

The W208/A08 fuel filter has 4 port connections and an integrated pressure regulator.

Enclosed below is the functional diagram of the fuel system that shows the various components and direction of fuel flow.




I've been a forum member since 2001 and replacing a clogged filter, should only improve fuel delivery and drive ability.

While changing the filter, the 4 detached fuel lines are very close together and it's important that each be one be reattached correctly to the new filter. If not, you'll definitely have an issue with fuel delivery or the Evap system.

But since you're not having reporting a dive ability issue, although rare, the humming could be caused by a defective filter , here or the pump's sound insulating sleeve, that's inserted between the fuel pump and clamp.

Scott&Kerry

Nope, no driving issues. Accelerates and runs like a champ. After a few hundred miles on the new filter, sometimes it stops humming. No rhyme or reason to it. I’ll look at the insulating sleeve. If that’s not it I’ll think about changing the filter again. Id like the hum to go away.

robby631

I made the mistake of installing an "off brand" filter. The fuel pumped hummed constantly, and after a few months I got stranded on I95. They had me over a barrel and after the tow and replacement of the filter (not to mention renting a car to get home), well, I'd be embarrassed to tell you what the adventure ended up costing.The guts of the filter had collapsed! Only OEM for me!