Jay wrote, "I've bought a torque wrench, and I'm going to be checking ALL of
these bolts every time I change the oil, from now on."

Jay,

I'm sure you know this from your motorcycle Zen days, but I've learned (and
relearned a couple times) to be certain the click-type torque wrench setting
is correct before using it -- and to loosen it completely before putting it
away. (Maybe the latter is an old wives' tale.)

I've also learned to be careful to note whether foot-pounds or inch-pounds
is specified. It seems that aircraft bolts are often torqued considerably
less than I would expect them to be.

Regards,

Jon (not an A&P or even a motorcycle mechanic)

PS: I shall now be checking my engine's bolts. Thanks for the heads up!