Loud fuel pump
 

Hi all!

This question pertains to my 85 380SE. I have a very noisy fuel pump combined with a cold start problem. I'm pretty sure the cold start problem is due to the fuel pump check valve, but I heard a new noise the other day that makes me think that the check valve might be the cause of the noise and not the pump. When I shut the car off the other day, there was a familar pitch buzzing after the key was out. The buzzing got quieter and then faded out.

Has anyone else had any experience with a check valve making noise while the pump is running?

Buzzing sound might be the vacuum pump in the trunk, sound might be confused with the fuel pump, same basic area if your listening from inside the vehicle. Only suggesting this as it happened to me with my 380 (85 se,) good luck, rainman

No, definetly fuel pump. I had the fuel pump relay fail on me and when I was doing the diagnostics, I enabled the pump using the jumper method. DEFINETLY the pump (related parts) making the noise.