Engine/Transmission (1994 - 1998) whistling Noise from Exhaust

[LLGood]

Twice this winter when I start my truck there has been a high pitch whistling sound being omitted from the exhaust. The sound can best be described like a high pressure air leak you would heard for a leaking compressor air hose. The engine runs fine and the sound has gone away after driving the truck. It did not do this in late December when I came off the last towing trip. The truck is a 95 dully. The engine is stock except a 4" exhaust system, which I added and a Exhaust brake that was installed by Cumman in 95. Any thought?



Thanks in advance.

 

[klaybus]

Whistle

Sounds like the Jacobs brake could possibly be engaged?

 

[ToolManTimTaylor]

Exhaust brake indeed. Doyu use t ite ofen? If not it nticartily od you will hear it. Another thing is that if you have guages you will see a rise in egt as well.



Moving this to the technical forum

 

[MLee]

So does it run OK when you drive it, or very sluggish? If the butterfly is closed it will not run accelerate but will idle.

Marv