Its been a few days since I finally swapped the fuel filter for a new one, and have given the car ‘the beans’ a few times again still with no re-occurrence of the noise.

Its looking more and more likely to be the fuel filter as the cause of the HPFP noise.

So Kudos to GraemeS for being the first to suggest this! 10 points  Currently driving: 2012 L322 SE Overfinch 4.4 tdv8

Past rides:
2014 Audi Q7 3.0d (good riddance)
2010 L322 Autobiography 5.0 Supercharged
2011 L320 HSE 3.0 sdv6
2014 Jaguar XF-RS 5.0 supercharged
2007 BMW 535D
2005 Mini Cooper S

https://www.fullfatrr.com/forum/topic59478.html

Frustratingly the squeal has returned. It’s been a pleasure basking in the refined quietness that is the cabin of an l322… however I bask no more.

I’m guessing it’s the hpfp that will need replacing… however, curious that the noise went immediately after the fuel filter was swapped? Currently driving: 2012 L322 SE Overfinch 4.4 tdv8

Past rides:
2014 Audi Q7 3.0d (good riddance)
2010 L322 Autobiography 5.0 Supercharged
2011 L320 HSE 3.0 sdv6
2014 Jaguar XF-RS 5.0 supercharged
2007 BMW 535D
2005 Mini Cooper S

https://www.fullfatrr.com/forum/topic59478.html

I was chatting to a local garage about this noise… which frustratingly wasn’t there at the time…
They suggested that as the new fuel filter fixed the issue for a few weeks, it was suggested I swap it again for a genuine filter? Certainly cheaper than a hpfp!

I fitted a MAHLE KC 521, which is what was there before.

Any thoughts? Currently driving: 2012 L322 SE Overfinch 4.4 tdv8

Past rides:
2014 Audi Q7 3.0d (good riddance)
2010 L322 Autobiography 5.0 Supercharged
2011 L320 HSE 3.0 sdv6
2014 Jaguar XF-RS 5.0 supercharged
2007 BMW 535D
2005 Mini Cooper S

https://www.fullfatrr.com/forum/topic59478.html

Fit a new filter but take the old one to bits and check for contamination, it sounds like the HP pump is being starved and what you are hearing is suction, it's possible there is bacterial bloom growing in your tank & lines causing the filter to block. If you have a UV torch, this will show up biological matter, if you don't, they're a couple of quid on fleabay - mainly used for finding refrigerant leaks.

Cheers Phoenix.
I have no starting issues, and no performance issues (I do have a lull in power as the 2nd turbo comes into play, but don’t believe that to be related). Given that there is no power loss, does the fuel starvation still seem likely? Or possibly an airlock somewhere?
The noise comes from the hpfp itself, and not the filter.

If it is contamination, is there an easy fix such as a fuel additive? Or would I need to drain and flush the tank and lines? Currently driving: 2012 L322 SE Overfinch 4.4 tdv8

Past rides:
2014 Audi Q7 3.0d (good riddance)
2010 L322 Autobiography 5.0 Supercharged
2011 L320 HSE 3.0 sdv6
2014 Jaguar XF-RS 5.0 supercharged
2007 BMW 535D
2005 Mini Cooper S

https://www.fullfatrr.com/forum/topic59478.html

If you can read the values for the volume control valve, that would give an indication of supply issues - it could also be a restriction on the outlet of the pump or return to tank line...
Personally, to rule out supply issues I'd put a cheap filter on it to see if the issue is resolved and open up the old filter.
If the tank is contaminated, chemical treatment will stop growth and kill of the bugs, but they have to go somewhere...
It shouldn't be too difficult a job to clean the tank in-situ, if a little unpleasant!

But that's an 'if & when' scenario....

With this conversation still fresh in my mind the family and I headed off to the beach. The car was quiet and we were happy enjoying the peaceful drive when I decided to overtake a slower car. A slight blip of the throttle and the car eased past as always… except I was a little more heavy footed than usual and she nipped to about 2,800 revs and the noise was back. All the way to the beach.

Several hours later we load the car back up with the over excited, tired and post sugar high kids into the car and almost straight away the noise was there. The comment this morning from phoenix about the “suction noises” made me think of a possible air lock or air leak so I parked up, sent the mrs off with the kids for a “try wee” and turned the car off. I then turned on the ignition but didn’t start. Left it for 30 seconds and repeated two more times. The thinking is that the car pressurises the fuel system on start and bleeds as necessary, so doing that a few times might help dislodge something?!?!

The good news is that whatever it did, the noise stopped! It’s still early, but when I am not ferrying the family around I’ll try to recreate the noise and hopeful solution.

Does this new information suggest anything different? Or am I best still getting a new filter anyway? Currently driving: 2012 L322 SE Overfinch 4.4 tdv8

Past rides:
2014 Audi Q7 3.0d (good riddance)
2010 L322 Autobiography 5.0 Supercharged
2011 L320 HSE 3.0 sdv6
2014 Jaguar XF-RS 5.0 supercharged
2007 BMW 535D
2005 Mini Cooper S

https://www.fullfatrr.com/forum/topic59478.html

Mate, chuck a cheap filter in it, cut the top off the old one and have a look at the filter material, until you do that - everything else is just a guess.

So, the noise came back!
Slightly different, in that it didn’t start making a noise when the engine was worked hard like before… but starts at random and for no reason. Also, the noise is quieter than before.
My last trick of turning the engine on a few times didn't cure it so off to t’internet to buy a new filter. I went for a LR filter rather than aftermarket to be sure.

The part arrived, and I set upon the work Saturday morning a few hours before travelling down to Essex for family celebrations. Swapping a filter is relatively easy, however I managed to pretty much empty the contents of the filter all over the engine and floor below. I blame the fact my gloves disintegrated due to the diesel and became slippery… and not because of my clumsy gorilla hands

Whilst the filters were out I also popped off the noisy pipe where attached to the plenum and at the filter end to check and everything seemed fine.

All well and good, however when I started the car, it took an age for the engine to stop cranking and to actually start. I had primed the fuel line 3 times beforehand. Once started she ran without any issues… until the noise started again.
I turn the engine off, and prime the fuel several more times but still the same long cranking.

I checked everything and the filter is screwed up tight, all connectors are good and visually everything looks good and leak free. I went for a drive and the car performed as per normal. There have been a few small journey since and the car cranks normally now so not quite sure what that issue was…

So now i am driving around with the noise constantly in the background… not loud as before, but very noticeable.

Any ideas why this is happening? And why i had trouble cranking the car despite several primes of the fuel system?

I am suspecting there is air trapped in the HPFP, primarily where the fuel return is. Again, the car otherwise drives normally so it doesn't ‘feel’ like a fuel supply issue as i would expect erratic performance and a change of noise depending on engine load.

I am now thinking of removing the fuel lines from the filter and checking they are all free flowing and blockage free. I may even consider a new low pressure fuel pump too, just because (apparently) they were a common-ish failure on other LR engines. Currently driving: 2012 L322 SE Overfinch 4.4 tdv8

Past rides:
2014 Audi Q7 3.0d (good riddance)
2010 L322 Autobiography 5.0 Supercharged
2011 L320 HSE 3.0 sdv6
2014 Jaguar XF-RS 5.0 supercharged
2007 BMW 535D
2005 Mini Cooper S

https://www.fullfatrr.com/forum/topic59478.html

From your last observations, it sounds like a restricted return line.

Here is mine, in my opinion it has something to do with fuel pump because sound depends on throttle position, not rpm.

Hi Umair,

Your noise is a different tone to mine, and yours seems to come and go whereas mine is constant.. but they are similar.
I haven’t gotten any further on mine yet due to a job change with home working… so simply haven’t been driving the car.

Have you managed to get any further with resolving your issue? Currently driving: 2012 L322 SE Overfinch 4.4 tdv8

Past rides:
2014 Audi Q7 3.0d (good riddance)
2010 L322 Autobiography 5.0 Supercharged
2011 L320 HSE 3.0 sdv6
2014 Jaguar XF-RS 5.0 supercharged
2007 BMW 535D
2005 Mini Cooper S

https://www.fullfatrr.com/forum/topic59478.html

I want to tackle this now following a frustrating journey to and from the train station…

My intention is to remove the fuel lines from the filter unit and filter pump and to ensure they are clear and free from any restrictions. I’m not sure yet how I’ll detach the pipe from the HPFP… but will see what i can do.

Are there any tips, ideas, or thoughts on what else i can do? Currently driving: 2012 L322 SE Overfinch 4.4 tdv8

Past rides:
2014 Audi Q7 3.0d (good riddance)
2010 L322 Autobiography 5.0 Supercharged
2011 L320 HSE 3.0 sdv6
2014 Jaguar XF-RS 5.0 supercharged
2007 BMW 535D
2005 Mini Cooper S

https://www.fullfatrr.com/forum/topic59478.html

Ffrr-lover wrote:

Hi Umair,

Your noise is a different tone to mine, and yours seems to come and go whereas mine is constant.. but they are similar.
I haven’t gotten any further on mine yet due to a job change with home working… so simply haven’t been driving the car.

Have you managed to get any further with resolving your issue?

Ffrr-lover / Umair … any updates on this. My rover has the same issue.

No performance issues but I hear a vibration at low speeds / constant rpm. It goes away and comes back. I have a check engine light that said it is the HPFP, mechanic replaced both and both the light and noise are still there.

Mechanic said the noise is not the HPFP and is compressor related to maintain suspension. He said if that noise like air in the HPFP existed then I’d 1000% notice a change in performance.