Repairing eng brake

[Waterloo]

Well, I can't help with the squeal, but under the lid of your motor, valve cover, is your engine brake harness. The harness gets old and brittle after a time and need to be replaced. It should enter on the Turbo side center. Inspect that, I bet that is your issue. It is plug and play and most dealers stock it. Also, there are clips that hold it all in place, sometimes they fail and work there way into the motor. Be careful when inspecting. I believe the new harness will come with new clips.