Odd noise after turbo boost (audio/video link)

WWDiesel · **Posted:** Tue Dec 06, 2016 10:00 pm

I would not recommend power breaking the engine at a standstill!
Doing so puts a huge amount of strain on internal transmission components and really stresses the torque converter stator and turbine blades as internal friction in the TC heats the ATF fluid super rapidly under such conditions.... :shock:

Bottom line, it is not good for your transmission unless you have a racing tranny that is designed to withstand such abuse! :roll:

GordnadoCRD · **Posted:** Wed Dec 07, 2016 3:52 pm

The condition that exists momentarily is attempting to spin the turbo in reverse, while the inertia of the turbo is still trying to create boost.

You have a high axial force against your compressor side, and a high radial force against the exhaust turbine, and the very mechanical noise is a result of the conditions in that particular instant. Once you pulled the boost hose off you removed one of the two conditions. the high axial force against the compressor.

Others having different turbos or even the same turbo in a different particular mechanical condition, may not be able to duplicate it, and really probably shouldn't try.

Unusual noises are normally not good news even if they are not especially bad news at the moment.

WWDiesel · **Posted:** Thu Dec 08, 2016 3:51 pm

GordnadoCRD wrote:

The condition that exists momentarily is attempting to spin the turbo in reverse, while the inertia of the turbo is still trying to create boost.
You have a high axial force against your compressor side, and a high radial force against the exhaust turbine, and the very mechanical noise is a result of the conditions in that particular instant. Once you pulled the boost hose off you removed one of the two conditions. the high axial force against the compressor.
Others having different turbos or even the same turbo in a different particular mechanical condition, may not be able to duplicate it, and really probably shouldn't try.
Unusual noises are normally not good news even if they are not especially bad news at the moment.

You are absolutely correct!
Never heard my Jeep diesel make the noise, but my big Dodge Cummins will make it if you back out of it suddenly while under high load or high power pull conditions...
I have been told by a diesel racer friend that it is called: TURBO BARK and is really NOT GOOD for your turbo!!! :shock:

So, I always try to let off the go petal slowly so it does not bark back at me!!! :lol:

mass-hole · **Posted:** Thu Dec 08, 2016 6:21 pm

Mine makes the noise occasionally when I am just driving and let out quick. Air pressure 20% lower here though so it could induce it easier.

Odd noise after turbo boost (audio/video link)

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