Terrible squeaking noise during accelartion DV6FD

[bobblberlo79]

Dear Berlingo mates :-)
this ist my first post after a struggle of diagnosing some issue with my berlingo!

It is a 2017 Model with the 1,6Bluehdi engine 73KW (DV6FD engine code). i bought the car in 2020 with 75.000km on it and was super happy so far.
At 130.000km car became a software update and was tuned on the dyno, achieving 120hp and 300Nm.
Car has now 170.000km and has been running strong since then.
I did oil changes every 10.000km and did regular maintanence..at 145.000km i also changed the Dieselfilter.
For the last few thousand km, the engine made a terrible squeaking sound that started slowly and became louder from time to time. It occurs under accelartion or as soon as boost pressure is building up (see in the videos here: https://www.youtube.com/shorts/x0KxKI4xwmM )

So i made another servie just now at 170.000 km where i changed the alternator belt and the tensioner, hoping that terrible noise would be gone. But no change. After that i changed the timing belt, water pump and tensioner, which should have been renewd anyway around that km (old timing belt was 5mm lenghtend btw).
No change, noise was still there.
So i tried to diagnose with some mates where that noise would be located but it just wasn´t possible, leaving me with the conclusion that maybe the turbo may have been worn out. Knowing that a turbo can not "wear out" in that way (it would eather work or be destroyed really quick) i ordered a new turbo anyway (rebuild original replacement part with flow protocoll and warranty). After finally changing the turbo, that noise was still there.

Further investigation lead me to believe that this noise would come from around the high pressure pump / timing belt area. Researching in the internet about failing of Bosch 1-piston HD pumps, let me believe that this may be the last and only moving part that could create such a terrible mechanical noise and i believed my HD Pump would be bad, expecting the worst (metal shavings inside the fuel lines, filter, injectors etc). So i ordered a new (rebuild) Bosch pump.

But before changing it out, i went to a fried and we checked all the relevant Data with his diagnostic tool and surprise surpirse: all the relevant data seemded fine, Injector quantity correction value looked perfect, no difference between each cylinder/injector, and pressure in the high pressure rail seemed also fine as it should be (257bar in idle, 1000 bar at higher idle), no trouble codes.

After further investigation today, i still couldn´t relate how that noise would occure. I found that the flange on the DPF that goes to the flexpipe was broken off (as seen in video here : https://www.youtube.com/shorts/0WNT5LuD40w ) hoping that that was the issue, so i disconnected everything but the noise was still the same.
After that step, i took off all turbo hoses before the throttle body, seeing if that would make any difference. Of course, car ran with all trouble codes, but i was still able to give it some throttle.
I believd the noise would become some more quiet, but hard to tell...
Finally this let me believe that maybe there is something going on inside the intake header behind the throttle body...OR mabye it could still be some issue with the pump?
However i not believe that the pump will have issues and create such loud noises, since Highpressure Pump failures mostly lead to quick enginge shut off and clear trouble coding, but the car runs great so far, no issue with power or fuel consumotion, just as always, regardless that noise.
On my last way home today, i made some value reading in real time with the tourque app (obd adapter) and the instrument cluster gave a value of 21000 psi rail pressure under full throttle in 4th gear at 2300 rpm, which seems too low for me (shouldn´t it be more around 28 000 psi or 2000 bar?!), but who knows if that readout wouldb even be correctly?

Long story shot, anybody knows something about such issue on that engine? Thanks so far Bobbl

[bobblberlo79]

Nobody?
Today looked at wot railpressure, which had its max at 1600 bar, isn´t that too low or is the pressure valve cutting off at that point?

[shtu]

Somebody.

Two ideas.

It sounds like an air leak. I'd compare boost requested with boost actual, though as it's mapped there's really no telling what figures might come up.

You've spent a fortune on parts, spend 100 euro on some rolling road time, get it up on load & boost and have a good poke about with it on the rollers.

[Drummond]

Hard to say after listening from tiny pad speakers, but I would second on boost leak. Only weird is the sound fluctuating during the acceleration.

[bobblberlo79]

truly sounds like a boost leak, i agree on that. But everything before the throttlebody seems alrgiht.
Investigating the fuel system, there were few metalparts found inside the fuel filter housing, one larger piece but mostly fine particles that are magnetic, not too much at all but investigation is going on.
The screen inside the highpressure pump valve however seems alright and is not contaminated...

Regaridng to the noise that could be a boost leak, i don´t know where else to look... Boost preussre was briefliy monitored and seemed ok, but will look further more into that.
Since loss of power wasn´t an issue and top end speed was like usual, i did not consider boost leakage..btw that fluctuation in that noise came from the new´s turbo wastegate, the wastegate rod wasn´t adjusted properly and thus the ecu could not find the end position of wastegateposition, resulting in triggering wastegate actuation, swap of the wastegate was the easy solution...

thanks so far fopr reply..will keep you updated

[bobblberlo79]

so here is the news: after dissasembling the pump, there seems to be everything alright, no metal shavings inside the pump, i bleed the fuel that was inside the pump on a screen and it seemed to be just fine.
Took out the head of the pump, piston and rotating parts where moving with ease, no signs of wear.
But hard to tell and maybe issues will just occur under load.
However i reckon this is much better than finding obvious signs of shavings and destruction.

Of course now will have to put in the new pump after going that deep. Still wondering if that noise could have another cause..maybe inside the intake port? Doesn´t seem like there is much more parts to investigate...

[Mark604]

Maybe daft question - it's definitely sounds like air movement, blowing out or being sucked in. If you've found nothing so far, is it air filter related? Casing, filter, pipe?

[bobblberlo79]

i found the issue today...it was just the egr valve...

[geoff]

Leaking joint ?

[bobblberlo79]

it was not the egr, thought it was the egr because after disconnecting the egr the noise was almost gone. only thing that happened was that the car go to limp mode and has no boost.
Whenever the boost increaes there is that nmoise again.
Egr delet did not help, neither mechinacal delete nor electrically.

Now i don´t know where to look, dissasembled almost the whole engine

piece of crap..there is no leaking joint. Whci joints do you mean?