Hi guys over two weekends ago I fitted a R Tech CAI (pipercross open cone) and compbrake diverter valve and since fitting (and after the initial drive) the turbo has been squealing. I initially believed that this was due to there being a vacuum leak somewhere.

 

I removed and tightened the diverter valve (it was loose) which reduced the noise but the noise is still there. Now I am curious if this is normal and if I hadn't noticed before purely because the stock airbox is quite good at reducing the noise or if in reality I shouldnt hear a squeal when on boost and have a boost leak/vacuum leak?

I will do a video tonight hopefully. Cars at the garage on friday for a boost leak check.

 

Any help is great guys.

If you have old dv you could try refitting and see if the noise is still there.

The cai will amplify the dv noise. Itll sound like a 'woosh' then youll hear the dump on lift off. Dunno about squealing though. Sure its not just the turbo spooling up?

Mcinvrs I'm not 100% it could be it spooling. Anyway as promised a video below 11 secs in the squeal/spool is there.

https://youtu.be/qPGXACUIeXM

Dont know what could be making that sound to be honest. Hopefully someone else on here might be able to advise you. Good luck with finding the problem anyway

Cheers fella. I think it's a vacuum leak somewhere and not something like a failed bearing in the turbo that has been amplified since the CAI.

So I took it to the garage, the garage seem to think it's normal for the turbo and just been amplified through the new CAI. To me its still high pitched but if its not the turbo on its last legs its happy days.

Its got a lisp!

 

Have you tried refitting the standard airbox to see if it is a new sound or just not noticed it before..

 

also check all the intercooler plumbing, sounds like it could be a tiny split in a hose starting as it only seems to do it around peak boost?

Update

 

So I took the car to CMC in Northampton above and they stated it was normal turbo operation - for a while last year I ran with the standard airbox on and noticed a drop in performance and MPG so went back to CAI and lived with the noise until June this year where I took it to VRS Northampton - they diagnosed an issue with the DV valve sticking and replaced the PCV hose.

 

Drove away - all good and then I hear it again 10mins into driving. Frustrated and a further £100 out of pocket I live with it whilst I go to the Ring.

 

I'm determined to find it so:

 

• my SAI is gone - it hisses on startup and I need to wait 3mins or it will kangaroo the car. Could this squeal on WOT?
• on part throttle at low RPM (coming onto boost) the car will spike (no squeal) could their be air coming in from a mani leak forcing the turbo to spin quicker at low RPM?
• I run a decat but occasionally recently with AC/heating on I can smell the emissions enter the vehicle unless recirculate is selected before I stop the vehicle - I wonder if a crack is formed in the mani?

Now I can't visibily see any cracks in the manifold but I don't want to replace parts willy nilly to not solve it. I feel I've done that a few times already.

 

Any ideas?

 

Octabus - I have changed to the standard airbox a few times now and whilst the sound is quieter it does not fully go away.

I cannot see any splits in the intercooler plumbing and the garages have yet to find any either.