Boost Leak on Xantia 1.9TD Estate

javadude · Post by **javadude** » 03 Feb 2005, 20:09

I think I have an air leak on the boosted side of the induction. I can hear it as I drive - from about 2,600 RPM to the red-line and stops when you lift off the accelerator - but I can't find the source whilst revving the engine with the bonnet open.
The visible pipes and connections under the bonnet look ok but I can't see the pipes to/from the turbo at the back of the engine.
Is there a way of gaining access to these? I can't see much from underneath either.
Is there a reliable way to test for leaks?

Kowalski · Post by **Kowalski** » 03 Feb 2005, 21:29

Are you sure you've got an intake side leak?
When my exhaust was on its way out it sounded like an intake side leak but it was actually the exhaust. Eventually it droppped off, after the new exhaust was fitted the noise stopped.

oilyspanner · Post by **oilyspanner** » 03 Feb 2005, 22:14

You can see one of the connections if you remove the offside front wheel and peer into the darkness, what you see should be (I think) the pressurised outlet from the compressor, if this has dropped off you would get the symptoms you describe.
Stewart

Kowalski · Post by **Kowalski** » 03 Feb 2005, 22:30

If your Xantia feels slow, what oilyspanner has suggested is possible. If its running at full speed / power its probably not.

BonceChops · Post by **BonceChops** » 03 Feb 2005, 23:03

Mine is a bit whiney. I have often thought I might take of the hose from the airfilter box and block it up. Remove the hose from the inlet manifold and find some way of blocking that as well. Then pressurise the bit between the blocked hoses to about 10psi and spray everything with leak detector spray and look for the bubbles. Hard bit is blocking up those big hoses. Mine is due to playing with excessive boost so it might be intercooler that is leaking. Last time i had a guage on it was still producing just over 1 bar pressure so I don't think I am loosing too much power from the leak.

roy_newell · Post by **roy_newell** » 03 Feb 2005, 23:24

For it to start at 2600 rpm it must be the boost leaking as thats about when the turbo will spin up fully so you will hear a distinct whistle, much louder if you have a leak.
And it stops when you take foot off the accelerator, its definately a boost leak of some sort. Have you only just noticed the noise or has it always been there, if its always been there don't worry, thats the sound of turbos, I'm guessing its only just started though so in that case there will be a leak somewhere, can't be that hard to find, mind you, if the turbo's at the back of the engine, good luck

Dave Burns · Post by **Dave Burns** » 03 Feb 2005, 23:45

Given that a turbo's compressor relies on centrifugal force to compress the air, then it naturally follows that the pipe you can see through the wheel arch, which enters the compressor at its centre, is allways going to be the intake.
The outlet pipe from the turbo on a 97 model is held on with two bolts through flanges, the seal is by "O" rings, it is extremely unlikely that the leak if any will be at this location, unless some clowns had it to bits and not refitted the "O" rings.
If you are convinced of a leak then look for cracked plastic pipes or loose connections to the intercooler and the like, some cowboys will bend the hard plastic pipes (and anything else thats in the way) out of the way when they throw a timing belt on.
Dave

javadude · Post by **javadude** » 04 Feb 2005, 14:16

Thanks for the advice everyone.
This is definitely a new sound. I reckon I have a leak in the turbo area as the garage that changed the cam belt recently advised me of a crack in one of the pipes connected to the turbo. They effected a temporary repair.
Anecdotally I would say that the damage was done earlier by some muppets who 'removed' the plumbing to gain access the glow plugs. The same muppets forgot to reconnect the pipe from the intercooler resulting in a monstrous boost leak, which, indecently, was easy to find and fix!
I must say that I like my car; it is comfortable and has proved reliable over the 3 years / 60k miles that I have owned it. However, when I open the bonnet I get depressed at the thought of having to work on it due to the lack of access. Is this particular to the Xantia or are other Citroens / manufacturers like it too?

Rob Marshall · Post by **Rob Marshall** » 04 Feb 2005, 19:39

Gasket between the intercooler & inlet manifold? The one on my BX went all soft & made a really horrible sound! Common to go apparently.

mipster · Post by **mipster** » 04 Feb 2005, 19:52

Perhpas it's the part I described - not obvious it was loose:
http://www.andyspares.com/discussionfor ... C_ID=11639