Replacement turbo with siren at low revs and hiss when letting of the throttle.

[Neil82]

Hi all, new member here so just thought I would introduce myself and say thanks in advance for any advice.
I'm Neil, live in Cornwall and purchased a golf gt tdi sport 2008 one week ago.
So the car drives fine with no power loss or any smoke really and I live the car but. It has a siren noise up to about 2k and a hiss when I let off the throttle. I would assume the turbo was knackered but I asked the guy about it when viewing the car and he said it has done this since having a new turbo. I took his word for it but am now a bit concerned as i don't want to kill the engine if it goes pop.
I have spent some time reviewing previous posts but just thought I'd ask here as you seem a helpful bunch.
Also anyone know any good turbo specialist in cornwall if it is toast.
Many thanks for any help. Neil

[Neil82]

Sorry should have mentioned it's a 140 bkd with no dpf. Been quite well serviced, engine seems sweet and has had a remap to 168bhp and a proper place did the map so I don't think there are any issues there.

[VAG-Abound]

I'm not sure you'll get a concrete answer as experiences on BKD turbo, snd DMF, vary so widely. The one on our Touran has been sireny and hissy for best part of a decade. Just took a risk that it'd be fine, and it has so far.

[Neil82]

Hi, vag-abound. Thanks for the reply. Yes I don't mind the noise that much just don't want the turbo to explode and take out the engine. Your car sounds reassuring, do you drive it normally or have to nurse it round a bit to keep the turbo alive?
Thanks again for the reply. It's nice to speak to someone who has the same turbo situation and it's been ok.

[Crasher]

No it doesn't sound right at all, you should have no whine, hoot or siren sound or hiss.

[Thorpey]

Sometimes new turbos do have the odd sound and have no play and can make the noise for years. A sure way would be to remove the turbo pipe and check for endfloat and see how much oil is in the pipe when it is removed. Are you sure there isn’t a slight boost leak? Check boost pipes for oil leaks on the joints.


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[VAG-Abound]

I drive it pretty hard at times. Red line up ramps for example to pass a couple of lorries so I have clear entry to motorway. I certainly don't go easy due to any worry about it failing. I'm not suggesting these noises are normal, but in my experience they aren't a precursor to imminent failure.

[Neil82]

Hi thanks for the info, sorry it's taken me a while to reply been feeling a bit rough. Is it easier to get at the turbo from underneath and other than a visual inspection is there a good way to test for boost leaks. Thanks.

[Neil82]

Reassuring stuff thanks for that and I hope you get many more trouble free miles from your touran.

[Crasher]

is there a good way to test for boost leaks. Thanks.

Pressure or smoke testing, either way pricey trade gear.

[Thorpey]

Soapy water over the boost pipes it bubbles if there is a leak


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[Neil82]

Only just noticed your message that sounds like a much easier prospect considering I don't have any specialist equipment.
I wont hold my breath but it would be lovely if it was just a boost leak.