Well, last night I decided to drain the 5w 20 oil and install some straight 30w. The engine was still hot from previous driving and I started it up and gave it a test drive up my favorite test hills and 40 mph straightaways here in the city. And ... no chatter when breaking.
In fact the car ran smoother and was generally more responsive. It reminded me of the vintage anti-chatter ads I’ve seen. Could it be as easy as that. It’s been years since I used 30w oil.
This morning I decided to give it another test since it was cold and different conditions than last night. Same thing. I drove around the neighborhood for about 1/2 hour and no chatter when breaking .. better driving.
Could it be that simple? Not anxious to start the car this winter with 30w but will definitely park it facing the door.