Hello everyone

I have a 2014 SDV8

the other day when opening the hood while the engine was running I noticed a strange noise coming from the CP4 injection pump, like a timing chain tensioner noise but it comes from the injection pump everyone knows that these pumps are fragile the noise is really audible when the rpm drops back to 1000 rpm

I checked the entire fuel system:

-pump relay R8 in the trunk
-the fuel sender in the fuel tank (stage 1)
-the lift pump (stage 2) under the engine ECU i have LHD.
-replaced the fuel filter twice
-common rail pressure regulator left
-common rail pressure sensor right
-FCV fuel volume control valve on the top of the pump

I found several testimonies from owners who changed the injection pump 800€ because this noise but the noise is still present after replacement


I also discovered that if you disconnect the FCV valve on top of the pump when the engine is at idle the noise disappears immediately


disconnecting this valve brings the pump to its maximum operating pressure, I don't understand why the noise disappears at high pressure, does anyone have any ideas?

I'm going to post a video of the noise, can the owners of TDV8/SDV8 4.4L tell me if it's normal? or if I'm paranoid?

Thanks in advance



Last edited by Astanavits on 18th Feb 2025 4:21am. Edited 1 time in total

Another exemple

Another one

Even a 2019 MY ??????? Listen at 0:59 ???? im not mad 😂

Update: Today I received and installed the stage 2 pump bosch 0986580131 / LR023043

problem not solved but the new pump seems to build up pressure faster and I can no longer hear the pump from inside the vehicle ,Obviously the pump is in poor condition, there was black fuel in the pump, I imagine that the pump in the tank must be in the same condition

next the in tank fuel pump

Hi everyone, I received the new in tank fuel pump today and installed it, quick work, really easy unfortunately the sound is still present it has diminished but it is still present

Click image to enlarge

Click image to enlarge

Update: today i open the high presssure fuel pump to see if i found any scratch or wear on the roller or the plunger hopefully the pump is in perfect condition

Click image to enlarge

the plot thickens....

its frustrating when you cant find an obvious solution... ... - .- -.




Y. O. L. O.
.

Exactly, I think the problem is not mechanical but software.

I’ve heard a lot of SDV8’s make this noise, mine does but yours does seem to have it bad, have you tried premium fuel, my own SDV8 does run better quieter on premium fuel.

I've tried everything diesel cleaner, Total Excellium (premium diesel), nothing seems to work.

Dave, what year is your car?

My current one is 2020, previous 2015 and both make this noise but more intermittent than yours sounds. It kind of comes in when full pressure is reached or that’s what’s it sounds like, then goes away, I work for a local indie where we work on lots of these and they all do it in varying degrees so I’ve put it down to a characteristic of the engine. But I do think premium fuel helps mine. Hope you get to the bottom of it.