V50 2.0D loss of power, goes into limp mode. Bad fuel pump?
 

New user here.. Any help is appreciated!

While accelerating in any gear, whenever the rpms are above 2k it will go into limp mode, not allowing the revs to go above 2k. After a little while (sometimes not long, and sometimes longer) power will come back with no issues at all. This will happen when the engine is at temp, or when it's cold. It'll happen just once, or numerous times.

I took it into a Volvo dealership because my OBDII reader wasn't picking up on anything. Their system didn't come back with any major faults, either. They said it's probably something wrong with the fuel system.

Sitting at idle with the hood open, and revving above 2k, you can hear something almost like a fan grinding. Hooking up the code reader and watching the fuel pressure, at idle it's about 22k psi, and it will increase steadily as rpms rise, but around 2.5k rpms, it'll get to about 44k psi, then it'll go into limp mode, dropping it down to 10k psi.

So there are a couple tiny bubbles in the system, but no large air pockets. My thought process is that the high pressure fuel pump is bad. Or that there is a crack in the fuel filter housing (as other threads have stated). But how the pressure actually drops, leads me more towards the pump.

Any thoughts? I just don't want to drop 300+ pounds on a pump without knowing for sure this is what's wrong with it.

Thanks!

2008 Volvo V50 2.0D SE (57 plate, euro 4)

have you fitted a new fuel filter,
get a fuel pressure tester and test the pressure before the high pressure pump,
Dave