Turbo Bark?

[Aerodyne]

When in a long pull in OD I get a loud noise and loss of power. I naturally hit the brake when this happens. If I lock out OD it never makes this noise.

Where should I start looking.


Aerodyne

[DmaxMaverick]

That isn't "turbo bark". If it was happening, it would be after you hit the brake. Turbo bark is the backflow of charged air (pressurized by the compressor) after a heavy engine loading, with a quick zero throttle. Once the fuel stops, so does the turbine energy, and the charged intake air flows backward through the compressor, causing the "bark" sound. This can never happen while under load.

The sound you are hearing is probably the engine cooling fan. It is loud. Typically, the engine will be more quiet in OD, so the noise is more profound, although it is probably happening out of OD as well. It can be less often, or go unnoticed due to greater engine noise at higher engine speed and a lesser load. The fan uses significant power, so you will also notice a power drop at the same time. If you had the A/C on, it would be a similar condition, although not nearly as loud. These are normal conditions.

Almost any other condition that would cause a significant power loss will cause limp mode, and/or the SES to light up.

[Aerodyne]

Thanks.

Taking a trip thru VA this weekend with a light load on the trailer. This time I'll wait before leting off the fuel.


Aerodyne

[Aerodyne]

Working 70 hour week for the last month so just now taking time to tell how the trip went.

First let me say this truck is a ball to drive. It only did the bark thing once, just 3 little coughs. It is not the fan.


Aerodyne

[Kennedy]

The bark that you are hearing may well be the EGR activating. There was a programming update some time back that reduced the duty cycle of the EGR to address complaints of a "popping sound" in the intake. This is also something that I take care of in my Kennedy Custom ECM programming.

[Aerodyne]

Thank you.

That sounds about right. Your delete plate is not helping any laying in the top of my tool box.


Aerodyne