Listening to the sound of the fuel pump with engine idling, I think I hear some whining. It is unmistakably detectable with the trunk open. Not sure if it is normal or excessive. So, I recorded the sound with my iPhone:

https://instaud.io/3UVv

Is it too whiny to be normal? Is my fuel pump on the way out?

 

Hi v1rok

That Whining sounds quite normal to me just so long as it doesn't include that other Crackling Sound!

Where is that coming from?

 

I think that “cracking sound” is what I referred to as whining of the fuel pump. But now that you said it, you might be exactly right — it is more of a cracking sound, rather than whining sound.

it was recorded by placing iPhone pretty close to the fuel pump, to avoid contamination from other nearby sounds. Maybe from 3 to 5 inches away.

By your reaction I assume the cracking sound should not be there if the pump was operating properly?

 

Mine does this to, I use lucas injector lubricant to quite it down, among other reasons. Modern gas is quite dry, anything that lubricates the system is good.

 

Hi v1rok

Maybe your iPhone was able to pick up sounds that the human ear could not properly hear even if you were standing very near

So I'm tempted to say that overall, it all sounds very normal and so maybe that 'Crackling Sound' is just Petrol flowing through the System

The time to start getting Paranoid!

Is when you hear that Constant 'Whining' Sound start to miss a beat, as that can be an indication that the Pump is then on the way out

No need to Spend $100+ on a New one, as these Pumps are generic and fitted to lots of Cars, so you could do what I did and get one off ebay for around £30 (plus a New Filter obvs!)

There's a lot of 'Badged' Stuff around these days, so there's no telling where its been made

 

Thanks. Made me feel a little better

i have a box of Techron injector cleaner. Was actually planning on adding a bottle once I hit low on gas.

Is Techron very different from Lucas injector lubricant?

 

Thanks. Will keep an eye on it. I thought that the sound was a bit louder than I expected, but what do I know?

 

Normal-ish.

I would ask:

How old the fuel filter?
How long since the plastic mesh filter INSIDE the small sump tank was cleaned?

Does this sound get more pronounced with heat, and I know its HOT in Nevada at the moment. Mine would whine more so when summer 45C heat hit, but much quieter when colder.

Fuel additives are much alike, and worth a try.

 

How old is the fuel filter? Don't know, honestly. I did not touch it since I got the car 2.5 years ago. Is it possible to determine the age of the filter? What is the normal frequency of replacing fuel filter and/or fuel pump on XJS?

Plastic mesh filter in sump tank. I have it on my "to-do" list. Will ty to get to it soon

Regarding whether the fuel pump cracking noise gets louder when outside temperature rises. This thought crossed my mind, too. But I don't have enough data points yet to make a determination. For some reason, I don't recall noticing the cracking noise from the pump previously. But it does not mean it was not there. Could be that I just did not notice it before.

 

Oh dear.

Unknown service items should NOT be on a "to do list" after 2.5 years. They should have been done and ticked off within 6 weeks of ownership.

Fuel filter, every 5 years or so, I do mine at 5 years, regardless of kms traveled.
Plastic filter inside that sump tank, DO IT NOW, it will most likely be clogged, and starving the pump for supply fuel.

No idea on data points, sounds complicated to me.

I drive mine, and LISTEN, when its HOT outside, the pump is barely audible, when its COLD outside, I dont hear it. That pump is 8 years old and a Bosh, Made in Germany pump.

My X300 had a whining pump, and at 160090kms, it died, bugga. Out with the tank, new Nippon Denso pump, modified bracket, clamp on supply hose, and all good, and that is audible sometimes when its HOT out. The R, is silent.

Average life of electric fuel pumps is 160000kms on a daily used car, those that sit for months on end would shorten that time I would think, as stale fuel is not good for anything.

It is a service item in my opinion, especially when first aquiring one of these neglected classics.

 

I guess mine just brought down that average a lot. It would have barely done 6,000, to say nothing of 60,000, still less 160,000....

 

It happens, as anything can be a dud out of the box, especially these days when we all know where things are made, OOPS.

Sons S3 XJ6, new pumps as part of the post purchase service, He used the LH tank mainly, but switched over from time to time, mainly when I pestered him to do so. That RH pump lasted less than 4 years. the LH still OK today, 9 years, and would be 85000kms old. We have pure fuel here, no Ethanol that is easily sourced, so maybe that is our saviour,

 

Mine started howling after a 2-3 hour rip. I just replaced it as the noise would bother me enough to ruin a perfectly good outing. I just assumed the racket wasn't a good thing. Why take a risk like that?

 

After some research (which probably took longer than it needed to be), I ordered Bosch 69414 fuel pump. AutoZone had it for $179, but Amazon had it for $90 (new), so half price. There were couple of slightly cheaper options, but I thought that Bosch should be good enough brand to pay a little more for extra insurance. And, the kicker that swayed me in the end is that the picture of the pump looks EXACTLY the same as the one I took out of my XJS (with Lucas name on it — suspect it is original pump), including the exact shade of brown top color. Will update once all pieces are arrived and installed...

 

Good move.

That Lucas sticker is only that, ON a Bosch pump, smart operation that Lucas mob.