3800 engine noise at idle and shut down

Just developed a noise only at idle and shut down. It is in the area of the power steering pump and the tensioner idler, so I replaced both to no avail. Using a rod to the ear, the noise is loudest near the front end of the valve cover nearest the power steering pump. This is a 1990 Buick LeSabre. Speeding up the engine or while driving, there is no noise. I get a minor clunk almost every time I shut the engine off.

Because the noise is loudest around the power steering pump and the belt tensioner spring housing, I don't think that it is harmonic balancer. I have never had the valve cover off and I don't know the valve train configuration. Is there a chain tensioner? Has anyone had a similar experience that has been solved?
I need a quick answer; my wife is demanding a new car.
Dieter
dieterschmied@gmail.com

23 year old car anyone's guess, no tensioner here. run the car with no belts on see what happens, look close at the damper, but a loose chain is common, get a wrench on the crank bolts turn the engine by hand back and forth see how much play in the chain you can feel.