Have I broken our 1.6HDi turbo charger?

[Welly]

On Saturday I took the Citroen for an Italian tune up, something I do every so often as the car spends most of its time around town and has a DPF fitted etc...

I did give it quite a heavy booting for about 1 mile so the car was pulling as hard as it could constantly.

On my return the Turbo made this noise as per this example vid:

zYyU8iOFj7Y

You can hear the turbo a bit on the 1.6HDi as its sticking up at the front of the engine but this noise has changed to this 'Siren' type sound.

I'm being optimistic and thinking the 'blast' has changed the sound characteristics of the turbo piping or even there's a leak somewhere?

Car drives as it should, no power loss or anything, internet suggests mainly VAG/BMW 'Siren' sounds and most people leaving it alone without further problems. Some suggests the bearings are goosed but that noise sounds more like air howling away to me??? what do bad bearings sound like? I'd guess more metallic and screechy?

[Doggy]

Air leak most likely.
Have a good look at all the joints and any sensor connections all the way from the air filter to the turbo & turbo to inlet manifold, including any egr plumbing.

[steve_earwig]

Shouldn't it be chucking out smoke if the bearings are shagged? No idea, turn the radio up

[Welly]

I'm thinking it must be an air leak on the positive pressure side feeding the engine, at the weekend I'll go around all the piping and see if anything leaps out at me....

[PeterN]

I think that sounds fairly normal with the pipe removed.

Peter

[Welly]

I understand what you're saying Peter but that video isn't mine, it's just a good example of the sound, all my pipes are still connected as normal.

[PeterN]

Ah right. The turbo on my Merc sounds like that, as though you are continually being chased by the police.

Peter

[Doggy]

Come to think of it, my first 406 did too - it had a completely empty cat/dpf housing and the flexi downpipe replaced with a thinner aftermarket equivalent. Therefore your noise could also be caused by changes in the exhaust.

Might it have just succeeded in completing a much needed regen?

[Welly]

Peter, that's exactly the sound, like a police siren in the distance.

Doggy I think I made my own regen because of the extreme hoofage I gave it, got a steady trip to High Wycombe on Saturday so see how it fairs, Sunday I will go around all the hoses etc, really wish I had a smoke testing machine to pump into it all.

[Welly]

Well High Wycombe was achieved with no drama's, car performing as it should, wind was a challenge though

After filling* with Dizzle I actually heard (for the first time ever) the Eoloys pump-o-matic doing something back at the fuel tank for a few seconds (adding the magic potion I guess) so I'm assuming the DPF is still cleaning itself otherwise there'd be fault lights all over the place. The internet said a blocked DPF can make the turbo sound funny (makes sense to me).

The wooo-wooo sound is definitely louder when the car is cold, this could either indicate the oil being less oily when cold or the air leak is 'bigger' with the cold hoses.

Sunday I saw one of the intercooler pipes looked slightly oily on the outside and tried quickly to remove it but it didn't want to budge in the short time I had. I did get a good few turns on the hose clips tightening them up "great stuff" I thought.........predictably this made no difference at all.

So I dunno, more checking to follow soon

[Doggy]

Turn the radio up?

You probably know this already, but received wisdom* recommends filling the tank right up to minimise the number of fill-ups and thus injections of Eolys. (You know, the additive that helps burn off the soot but then blocks your dpf with its own residue).

[Welly]

The jury's still out on the full fill ups routine...

We* have taken this thing from 30K to 66K miles with purely random £20.00 / £30.00 "fill ups" (when the low dizzle light in on) and not had any issues so far. The owners book of lies says for me to be ready for all kinds of pain at 72,000 miles when the 'pouch' of magic needs refilling and something resetting.

I am going to ignore the woo-woo siren but feel a bit sorry if I've actually made something worse by driving hard, should have remembered when I took the 406 for its first Italian Tune and the MIL light came on the next day (radiator fan I think that time).

[steve_earwig]

...really wish I had a smoke testing machine to pump into it all.

I just watched a DIY one on youtube (which I'm not going to link because irritating) but basically, a jamjar with a soldering iron through the lid, also pipe in and pipe out, baby oil, a bicycle tyre pump. Oh, and a pair of old socks, err...

Dammit, I'm going to have to link it 'cos this ain't gonna make sense https://www.youtube.com/watch?v=L9CDZ9lu6Rs Annoying music alert.

[Welly]

That's quite an ingenious idea actually

[Welly]

Did an oil change yesterday on the DV6, to gain access to the funky filter cartridge housing you have to remove a piece of the air inlet to the airbox...."this feels a bit funny".....the inlet elbow into the air box had popped out and was facing down towards the back of the engine right at the bulkhead. There's basically been a large open hole in the airbox right behind the dashboard.

Plugged it all back in properly so that fresh air from behind the headlight was being fed directly into the airbox as designed....completed oil change (why does it take longer to wrestle with the under-tray than to do the oil change ) went out for a drive and the whoo-whoo sound is massively reduced (or gone I guess) and dare I say the car feels a bit more perky - it's been living on hot air recently - I did think that a slight sluggishness came at the same time as the siren noise so this now makes sense.

Some tie wrappage was deployed to secure the floppy-about Citroen air ductage so hopefully case solved