Whistling Turbo and Brakes

Guru Meditation · Unread post by **Guru Meditation** » 23 Dec 2002, 23:34

Hi all.
I recently posted that I was about to buy a 93k zx 1.9td aura. Well, I have it now and I have a couple of questions!
When driving I can hear a whistle whenever the turbo is on boost, from around 2000rpm. It occurs in every gear and if I lift off while accelerating it subsides, then will occur again when I accelerate. The whistle doesn't occur when revving when not in gear. The whistle is quite loud. It is not as high in pitch as say a whistling kettle more like a kind rushing noise. The car accelerates as normal (as far as I'm aware, never owned or driven TD before, but it feels fairly rapid and torquey so I'm sure the power is all there). The noise sounds like it is coming from the passenger side in the engine bay (obviously!). As it only happens when the turbo is on boost I'm sure it must be something to do with that but I'm not certain what it is, may be an air leak or something? Never owned a TD or any other turbo charged vehicle before ao any thoughts would be greatly appreciated!
Secondly what brake discs and pads can any one recommend? The brakes judder a bit even after the discs have been skimmed so some new stuff is in order. I don't want uprated stuff just the best standard stuff (I hear Halfords discs often come warped for example). I of course don't want to pay Citroen prices.
As an aside I have my first Citroen anecdote. Managed to drive off with no lights on this evening. Got caught out by the always illuminated instrument panel

didn't crash or anything so lucky there

Only ever done that once before in nearly four years of driving.
It's the turbo whistling that's worrying me though. Thanks peeps.

Dave Burns · Unread post by **Dave Burns** » 23 Dec 2002, 23:56

Swollen and leaking rubber gasket between intercooler and manifold may be.
Brake discs, the best Iv'e ever had were made by Brembo, got Bendix originals on my Xantia at the moment, buggers have only been on since August and done less than 5000 miles, but the toads are warping so I'm not impressed, going to fire the sods off and stick some more Brembo's on.
Pads, EBC kevlar, softish compound lots of bite, and because they aren't full of big bits of metal they don't chew the disc up.
These are especially good for rear disc brakes because the lower power rear brakes can have a tough time wearing down hard pads, with the result that the disc often goes rusty except for a few small tracks that coincide with hard spots in the pad.
Merry crimbo
Dave

nick · Unread post by **nick** » 24 Dec 2002, 03:54

My Xantia TD suddenly began making a whistling noise under the same conditions as your car, and it turned out to be the inlet manifold gasket had become brittle and started leaking.
Its certainly worth checking the (more accessible) intercooler connections first as Dave has suggested though.
Nick
Edited by - nick on 23 Dec 2002 22:55:15

louis1 · Unread post by **louis1** » 24 Dec 2002, 07:52

Hi i have a 1993 zx td and it does the exact same regarding the whisling turbo. it seems to do it more when using the torque eg up hills&in a higher gear. i still have not solved the porblem but there is a split in my intercooler rubber so i will do that soon and will let you know if it cures it.
cheers

Guru Meditation · Unread post by **Guru Meditation** » 24 Dec 2002, 17:16

Louis1. I agree it seems the higher the load on the motor ie up a hill etc the louder it gets. I suspect a leak somewhere as has been suggested by others. I would be interested to hear if you manage to sort it. I will be investigating myself at some point in the next few days so I'll let you know how I get on.
Cheers.
Guru

Unread post by **RichardW** » 26 Dec 2002, 17:59

On the BX there was a small rubber seal between the intercooler and inlet manifold, as mentioned earlier, this deterorates and leaks, making a very effective whistle. It will be worse under load (hill climbing etc) as this is when the turbo generates most boost. You may be able to find the leak be revving the engine and then (carefully!) running your hand over all the tubing etc to see if you can feel where it's coming out.
Richard

louis1 · Unread post by **louis1** » 27 Dec 2002, 02:07

Hi nick i will replace my intercooler rubber as soon as citroens open up. when you changed yours did the performance change because my one seems slow, inless i am getting used to it

nick · Unread post by **nick** » 27 Dec 2002, 14:56

It wasn't actually the intercooler rubber I changed on mine, it was the gasket between the inlet manifold and the cylinder head. Xantias have the intercooler mounted in front of the radiator behind the front grille, so its connected by a series of plastic pipes rather than being mounted directly onto the manifold.
Really an air leak of this type can occur anywhere between the turbo and the engine. This is always a potential problem with turbocharged (or supercharged) engines as the inlet manifold and part of the air intake is under pressure, as opposed to a vacuum on normally aspirated engines.
I didn't notice any change in performance when it was repaired, it was just the noise that was driving me mad <img src=icon_smile_sad.gif border=0 align=middle>
It was so bad other drivers and pedestrians would stare at the car trying to work out where the noise was coming from !!
Nick