Technical Jtd Whistle !

[TinkersRucksack]

Folks

I've not seen any reference on the forums to this problem, so your thoughts / suggestions would be welcome.

My 53 plate 115 jtd dynamic "whistles" when the engine is cold. It sounds like the noise of a distant police siren ! The pitch rises and falls more or less in line with the revs. Once warmed up, the noise fades almost completely. My wife says it's like driving a Ice Cream van ...

Anyone else had this problem - if so, any soultions ??

Cheers

TR

 

[Stilo_ste]

Turbo whine ? Is the exhaust fully sealing from the manifold to the first box when cold ??

 

[Deckchair5]

My 53 plate 115 jtd dynamic "whistles" when the engine is cold. It sounds like the noise of a distant police siren ! The pitch rises and falls more or less in line with the revs. Once warmed up, the noise fades almost completely.

Also the alternator is working hardest when recharging the battery after starting in the cold weather. See if it gets worse when you load it even more with heated rear screen and headlights at the same time in which case it could be alternator belt, a poorly battery or just a noisy alternator

 

[Multiplewagon]

My car's turbo has a differnt sound at the minute with the smoking and low rev lack of power it is suffering with... wonder if its connected.

 

[Quiz]

MY wIFE HAS JUST BOUGHT AN 04 MODEL THAT 'WHISTLES'. DID YOU FIND AN ANSWER TO THIS ?
Quiz.

 

[1.8Stilo]

could be a thought, but the GP turbo suffers from "whistle" heres an explanation of the whistling noise from the garrett website:

What is causing my turbo to sound like a sewing machine's whistle?
The "sewing machine whistle" is a distinct cyclic noise cause by unstable compressor operating conditions known as compressor surge. This aerodynamic instability is the most noticeable during a rapid lift of the throttle, following operation at full boost.


and then what compressor surge is:

What is compressor surge?
The surge region, located on the left-hand side of the compressor map (known as the surge line), is an area of flow instability typically caused by compressor inducer stall. The turbo should be sized so that the engine does not operate in the surge range. When turbochargers operate in surge for long periods of time, bearing failures may occur. When referencing a compressor map, the surge line is the line bordering the islands on their far left side.
Compressor surge is when the air pressure after the compressor is actually higher than what the compressor itself can physically maintain. This condition causes the airflow in the compressor wheel to back up, build pressure, and sometimes stall. In cases of extreme surge, the thrust bearings of the turbo can be destroyed, and will sometimes even lead to mechanical failure of the compressor wheel itself.
Common conditions that result in compressor surge on turbocharger gasoline engines are:
A compressor bypass valve is not integrated into the intake plumbing between the compressor outlet and throttle body
The outlet plumbing for the bypass valve is too small or restrictive
The turbo is too big for the application

check it out if you wana read:
http://www.turbobygarrett.com/turbob...nter/faqs.html

hope it helps!

50% of the GPs do this all the time, most when underload and have no problems. Though a few have blown turbos

 

[john55]

That information appears to be related to Petrol engine Turbos. there us no dump valve on a JTD and none is needed.

It is normal for a variable vane turbo as fitted to 115hp JTD's to give a slight whistle, most noticeable when you take your foot off the accelerator to change gear.
If it overly loud, or audible inside the car it is often due to a hole in the exhaust, or your turbo is about to die it a cloud of smoke.

Alternatively, it sounds more like the original problem is a failed belt tensioner on the engine.

 

[mingsect]

it really depends on the whistle.

chances that it could be the timing belt tensioner.
or the fan belt /aux belt tensioner / pulley ..