Oldsmobile/Buick Repair: Engine whine caused by EGR valve?, buick park avenue, engine whine

Question
I own a 1988 Buick Park-Avenue with 112,000 miles. As I was accelerating up hills, I began noticing a whine from my engine, as well as a loss of power. The car ran fine in lower RPMs. In the course of a week the noise began getting louder and would occur at lower RPMs and I would notice a massive loss of power. The service engine light came on and indicated a code 65 which deals with an EGR failure. I cleaned the EGR valve and its passageways. The problem seemed to go away until the car was running about a minute, and then the whining on acceleration (beginning around 2500 rpm) continued. When I cleaned the valve, I noticed the electronic part of the valve was beginning to melt at the bottom. I was wondering if I should replace it, or if the new one would still cause the whine and begin to melt. I have never heard of a EGR valve whining before. This one really has me confused. Any help will be appreciated.

Answer
Hello Ethan,
Something there would have me checking the exhaust system, to make sure it isn't plugged up. Including the muffler.
Any sound of hissing from under the car while under heavy load? Like exhaust gasses trying to escape through the joints?

Have you tried running it with the EGR disconnected, just to isolate the whine?

Van