Subaru: Clattering noise from somewhere in the front of my 1997 OBW

I've got a clattering kind of noise coming from somewhere around the
engine of my 97 Outback Wagon. It happens at high RPM, in two
situations. Most often, when I am up at the top of 2nd gear, and press
on the clutch to shift. As I take my foot off the gas, it clatters for
a moment until the RPMs drop down. It also happens at the top of 2nd or
third gear when I am going downhill and take my foot off the gas, and
stay off the clutch. With the engine RPMs held high by the downhill, it
starts to clatter.

I've made various attempts to get this diagnosed. First, early this
past summer, they told me it was my catalytic converter heat shield
rattling. They put a clamp on the shield, but the rattle has persisted.
Then, last week, I took it in, and they found an oil leak, and said
the clatter was from the valves rattling because there wasn't enough oil
in the engine. They fixed that ($1200), and the rattle may be better
than it was, but still there.

I am aware of the chronic heat shield rattles in these cars, so I spent
most of this afternoon under the car, trying to tighten the shield up.
I tweaked one section of the shield, but found nothing else that seemed
loose enough to rattle. Nevertheless, the rattle is still there. I am
a bit fearful, because it does not sound to me like something as simple
as a heat shield.

Could the valves be damaged because of the oil leak? Or, am I
underestimating the possibility that the heat shield is rattling. I
suppose I could take the shield off just to diagnose it. Not going to
leave it off though.

Anyone had this experience? Any advice?

Find another dealer. Anyone who charges me 1200 dollars and doesn't fix the
problem is not a mechanic but a parts changer and not a good one at that.
"Mike B." <com> wrote in message
news:0cqxb.22031$news.atl.earthlink.net...