300SD Turbo wastegate sounds like coach-whistle at speed!

I'm going crazy! My turbo is silent until I hit 60mph, whereupon it suddenly begins making a shrill coach-whistle sound. If I accelerate it vanishes, if
I go slower it vanishes. If I cruise from 60mph and faster steadily it's there screeching away under my hood, amazingly loud. I think it's the wastegate as it's not a bearing noise. What would make a wastegate sound like a coach-whistle? How do I replace it? I looked at a removed turbo at a shop, the gate seems to be impossible to remove, four screws on the back remove a cover and gasket revelaing a slot sized for a huge flathead screwdriver. If I turn the slot it rotates the top half of the gate. I also noticed the gasket that I removed from the back plate was split inside. Could this be why my wastegate is whistling?
If it helps, it's a 81 300SD. Please feel free to reply to my personal email: snipped-for-privacy@hotmail.com. Please remove the obvious spam-foilers. I'll check the group too. Thanks!
Doug
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
300SD Turbo wastegate sounds like coach-whistle at speed! xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx mine <82SD> had a problem with the gate not closing and taking forever to get to speed.plus having a mind of its own!
cleaned out the bango fitting on the intake and replaced the vacumme line leading to the altitude compensator no more lost power.
the choo choo noise MAY be the gate not properly been told what to do. mine makes noise at aprox 1/2 speed
case xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx (Doug) I'm going crazy! My turbo is silent until I hit 60mph, whereupon it suddenly begins making a shrill coach-whistle sound. If I accelerate it vanishes, if I go slower it vanishes. If I cruise from 60mph and faster steadily it's there screeching away under my hood, amazingly loud. I think it's the wastegate as it's not a bearing noise. What would make a wastegate sound like a coach-whistle? How do I replace it? I looked at a removed turbo at a shop, the gate seems to be impossible to remove, four screws on the back remove a cover and gasket revelaing a slot sized for a huge flathead screwdriver. If I turn the slot it rotates the top half of the gate. I also noticed the gasket that I removed from the back plate was split inside. Could this be why my wastegate is whistling? If it helps, it's a 81 300SD. Please feel free to reply to my personal email: snipped-for-privacy@hotmail.com. Please remove the obvious spam-foilers. I'll check the group too. Thanks! Doug
the case, minus a few cans!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Wastegates do not whistle. Check for air leaks in any hoses connected to the manifold, or leaking exhaust manifold-to-head gaskets.
Bill Ditmire Ditmire Motorworks,Inc. 425 White Horse Pike Absecon,NJ 08201 http://www.ditmire.com 609-641-3392
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.