Turbo whistle

[Philjw]

Hi all,
130K miles in and I can hear a whistle from the turbo on the C5.
Does this mean trouble ahead? What should I be checking?
I could convince myself that the power is not being delivered smoothly at a constant throttle setting There seems to be a slight pulsing.
Any ideas?
Thanks

[Peter.N.]

If you can hear a whistle that only means the turbo is working, an excessive whistle could be caused by a leak in the pipework which could also reduce performance, check the hose connections on the turbo.

Peter

[Lighty]

If you have no leaks , and tbh, a leak doesn't usually whistle, it hisses. It is most likely that the Turbo impeller is out of balance. Over time, the turbo will likely get hit by tiny particles of dust, or worse, depending on how cleanly the filtration is maintained.
Years ago I had a low mileage 306 TD with a terrible whistle, after trying all else, we sent the turbo away, it looked like new, but the repairers balanced it, it was completely silent afterwards.
I would think it is unlikely after such mileage that you would get away with this , prob requires an overhaul, once removed.

[KevMayer]

My C5 turbo used to whistle loudly. But, since I've cleaned out some of the crud from the inlet manifold, the turbo is a lot quieter. It appeared to me that the clean manifold allows the engine to breath easier and so the turbo doesn't have to work so hard.

[steelcityuk]

I fitted a after market exhaust to my 405 TD and it whistled quite loudly, the problem was traced to a poorly fitting joint. Surprisingly it wasn't noisy in the usual way.

Steve.