I have a 2008 2500 6.7L. I was returning home from Florida towing my 32 ft travel trailer and when I would decelerate the engine break would engage but it would whistle. Does anyone know why it might do this??
Thanks
6rixs

 

I would check for an exhaust leak either where the turbo housing bolts on to the manifold (most likely place), or at the manifold itself. With the exhaust brake on, the pressure of the restricted exhaust could be forcing itself past a gasket.

 

with the exhaust brake on you can hear the turbo whistle clearly.....that's normal when you decelerate...

 

Agreed. My truck was making a squeeling noise w/the e-brake turned on...sounded like a belt slipping...louder when being worked hard and could be modulated with the throttle pedal. The service tech found a bolt had backed out on the egr cooler.

Tapa daba do...

 

90% chance it is a blown gasket between the EGR cooler and exhaust manifold. typically the rear under the firewall is the culprit. can't count how many times I have been under the hood and they are finger tight.

 

It does help if you can count.