C5 2.2 HDI making police siren noise

[Elliott19864]

Hi, just signed up as I need some help with the parents car.

It was making a loud whistle and police siren noise and throwing up anti pollution fault etc so I replaced the swirl valve actuator which was split along the fold line.

Although the car is still making the same noise but hasn't brought back the fault yet.

I noticed some oil at the base of the inter cooler so pressure tested all the system but couldn't find any leaks.

The noise is definetly coming from the turbo area but couldn't find any leaks around that area either.

Is the turbo goosed or is there simply a split vaccum/boost hose somewhere
I haven't checked.

[The Birdman]

Peugeot 407 turbo`s whistle aswell , any soot at the top?

[Elliott19864]

Can't say I have noticed any soot.

Car 'runs' fine, just feels underpowered to me, not much punch from the turbo.

Would it log any faults even if there was no lights on the dash?

[cachaciero]

The swirl valve and turbo control share a common vac supply, failure with age of the rubber joiners is quite common, if the turbo control actuator is not seeing much in the way of vac then it will be in max pressure mode, however if that was the case I would think that you should get a warning with limp mode because of overboost. A lexia would allow you to measure the inlet pressure in real time.

cachaciero

[Elliott19864]

The fault has came back now, anti pollution coming up on the dash.

[jbraud]

Hi, I've recently bought a C5 with only 82k on the clock. It does appear to be suffering the same whining noise. I find that if I put my toe down in say 1st/2nd, it will whistle louder and faster than the engine actually revs so sounds a bit like escaped air. I accept that the turbo needs looking at (which is bringing me out in a sweat), I did have a question though.

It also has an oil leak which I'm yet to look at, would it be likely that the two issues are linked? I've seen enough comments around about oil spray for a leaky pipe to the turbo and a leak is somewhat sensible as there isn't a huge amount of power. Don't get me wrong, it will accelerate but not at a rate I would expect of a 2.2l turbo.

Oh and one more thing, as you engage the clutch, you can really feel some vibration through the clutch pedal itself, is this quite normal?

Sorry about the list of questions, I always hate buying cars and getting used to them.

Thanks,

Jon.

[KevMayer]

My 2.2 Hdi used to make loud whistling noises when accelerating. But, it's a lot quieter since i've used a spray to clean out the oily gunk coating the insides of the inlet manifold.

I suspect that the whistle is due to the turbo struggling to provide air flow through the caked up manifold. This would also explain the lack of power.

As I say, it's a definite change to my c5 since using Wynns EGR3 spray.

[jbraud]

Thanks for the update, that's quite interesting. I have noticed that it quietens down when the engine is up to temperature which is interesting. I had this theory, based on people's experiences, that it may be worth checking the swirl valve actuator diaphragm though I'm not as convinced anymore given than the problem comes and goes. Do we have any other ideas besides that which you've used to cure yours? (which I'll checking).