CRD turbo whistling maybe

2008 CRD / Full NADS (Manual boost control - dawes/needle), ECU postal remap, 3" high flow exhaust SS (muffler/cat) Safari snorkel, stock air resonator box and ducting.

I can hear it again!!!!, that sweet song (fox whistle like sound, 2 sec ascending and then 3 seconds descending).

Just when I think I have the boost and spool set just fine, as I back off from a load situation and coast / boost eases off and then I hear this fox whistle like sound maybe coming from the snorkel intake and appears to be possible coming up from the turbo.

Not an unpleasant sound and did occasionally experienced it with the stock ecu (eng running well). Max B 16.5 psi /cruise 15psi

Post ECU remap, today, after some further needle adjustment and again its singing (good run). Remapped ecu in 2 wks now. Max B 21psi /cruise nom 16psi.

Any idea of what the whistle song is about and what may be causing it?

We had a similar sound in our old 2000 Gu and it was a slight warp in the exhaust manifold but was a nightmare to detect because once the engine heated up the manifold would heat up and close the hairline crack. Also had a similar sound with slight hairline crack in intercooler too.

Quote:

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(fox whistle like sound, 2 sec ascending and then 3 seconds descending)

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Like yesturday, heard it after travelling 40km into town and came on intown and also when cruising back home on hwy (no real load situations).

Was your sound constant over long duration or short duration as quoted?

Did you find a soot trace where it was leaking or went were your ear took you?

Did fit EGR plate at exhaust manifold. New TIG I/C

Mine only whistles on the move never stationary.

Hey mate. Had a whistle on my last 2009 crd.
It was much more evident under boost and when motor warned up.
Ended up being cracked EGR pipe at the back of motor near the turbo side.

Sent from Note 5 using TapaPro

If the sound is coming from the snorkel, nothing to worry about. If its from under the bonnet, it could be the issues stated. Spit EGR pipe is not uncommon for the CRD's.

i have a snorkel and 3 inch exhaust . i occasionally noticed a slight whistle after fitting the snorkel but after fitting the pipe i notice it all the time . the turbo whistles as it spins up under light load and when it winds down when the motor rpm is less than approx 2500 rpm and slowing down slowly . it's pretty much normal on most diesels with these mods.

yeah i have done a exhust manifold and need to do another on mine(sorry mrs's)and it is only under load never heard it de excalorating

Thanks fellas.

For the EGR block, I put the solid block plate at the exhaust manifold.

Have a plate for the egr valve end of which I may install latter. Would provide protection if the EGR assy water jacket punctured. Don’t want water going into the cylinders (not a big priority at the moment).

nipagu7, I also consider the whistle is coming from the turbo (thanks) and is being ducted up through ducting to the snorkel intake port (thanks mudski for the re-assurance).

And yes, the whistle as I observe it, occurs when eng is coming off load. IMO, I think the whistle is created by resonance ie: when the turbo is spinning down and may be caused as a result of the diminishing load caused by the reduction in exhaust back pressure and the subsequent reduced axial force/load being applied to the turbo rotor.

I initially thought this is what is referred to turbo on song (maybe not the correct term for this scenario). Thanks again.