scottalexander

2010 e60 N52k

I just replaced the fuel filter. I did NOT replace the fuel pump.

Before I re-installed the back seat, I started the vehicle and checked for leaks at the lock ring.

The sound of gas moving through the fuel filter was moderately loud.

Then for about 5 seconds it would get even louder.

Then the sound would drop down again to moderately loud.

This would repeat itself.

Does the fuel pump have constant PSI pressure to the fuel rail?

Does the fuel pump have variable PSI pressure based on whether the car is idling or at 5,000 rpm?

seanjordan20

You should be getting 72 psi at all time +/- 2.9. The fuel pressure regulator controls the pressure at the engine via the ECM. The pump just pumps at 73 psi to a max 109 psi. Max voltage is 12v with an average of 10v at normal operation. So saying all this it would fluctuate

scottalexander

The fuel filter I just replaced was a Bosch.

There was a little piece of paper inside that said, most fuel pumps fail due to impediments and dirt clogging the fuel filter and the fuel pump.

Doesn't the fuel pump fail most of the time from overheating (low gas in the tank) ?

seanjordan20

It's both. If fuel is low it has to work harder and picks up the dirt from the bottom. I have never changed a bad pump with a filter that was dirty so my experience is just as you said owner keeping fuel level low all the time.