10 replies to this topic

[snotvomit]

I was looking at the post by jameslemanski about a sound that might be a leaking manifold (http://www.vx220.org...ine-on-startup/)

I was trying to explain the sound on mine since the remap/precat removal but it's difficult to describe sounds so I have tried to record it. It was raining, so I recorded from inside the car.

There is a high pitched whining sound that changes in pitch with the revs. I though it was some kind of induction noise but after hearing it in the video on the other thread, I am not sure now. I don't know if this was the sound that james was concerned about in his thread.

Here is the recording: http://s105.photobuc...nt=SDV_0009.mp4

Any comments or advice would be most welcome.

I really hope it's not my turbo manifold

Is the sound normal?

[Nev]

That certainly sounds like it could be boosted air escapeing. Block the tailpipe up and that will help exacerbate the noise and help you locate it. You may even see/feel where its coming from if you look around when reving fairly hard.Check the mainfold and then all boost pipes to the top hat.

Edited by Nev, 20 November 2011 - 07:55 PM.

[snotvomit]

Thanks Nev - I have tried looking for obvious bad connections but I can't find anything. I have a boost gauge but that seems to be reading normal vacuum/boost. It really is quite noticeable and identical to the sound in the other thread. I was hoping someone might have had experience with the same sound.

[Nev]

Thanks Nev - I have tried looking for obvious bad connections but I can't find anything. I have a boost gauge but that seems to be reading normal vacuum/boost.

It really is quite noticeable and identical to the sound in the other thread. I was hoping someone might have had experience with the same sound.

The Z20LET turbo manifolds are reknown for cracking. If it is that, just chck it in the bin and buy a new Z20LEH turbo off ebay for £400 and replace it. No remap required, so long as you adjust the actuator correctly.

[snotvomit]

Yes - if necessary I will get an LEH turbo but I have no idea about fitting it and I'm not sure where to take it in this area for that kind of thing. It's disappointing, though, because my car is a VXR and I know that have some kind of fancy hybrid turbo in them. It would be a shame to bin it but I suppose there will be little option if it's the manifold because it's part of the turbo unit, yes? The car has been remapped, so is it just a matter of making sure that the replacement turbo has the actuator adjusted the same as the turbo that is removed? That will be somewhat of a relief.

[siztenboots]

imho I don't think it sounds like turbo , more like something on the cambelt. you could try unplug each of the two vacuum solenoids and see if you get turbo chatter when rapidly closing throttle.

[snotvomit]

Thanks for the replies. I will try the tests suggested here (blocking tailpipe, disconnecting solenoids) before I write the turbo off and order a new one. The car only has 11500 miles on it (5500 of those in the year I have had it) and I had the cambelt done when I got it last year. I didn't do the water pump, though, because I thought that it would be OK with 6000 miles on it. It was the video in the previous thread that made me worry that I might have a cracked manifold bacause I can hear the same whine in the background on that one. Thanks again for the advice.

[bigp2]

Thread resurrection, I've got a similar (but worse sounding) issue. The whine does seem to be boost dependent, not rev dependent, so I can only assume it's the turbo and not a belt. Doesn't seem to go away when the engine is warm, so not the turbo manifold. Am I right in thinking the actual turbo is buggered? Phil

[Nath]

That sounds shite! Looks of things, you dont have much boost either

[chris_uk]

Awww look... The turbos pretending to be a supercharger

[JG]

Dead turbo I'd suggest