Turned out, it was a leak in the cooling system ...
The shop is called Mini-Madness, in Hillsboro, only a few miles from here. I did a web-search and found it, and while their primary business is hot-rodding Mini Coopers and Beamers, turning them into racing bombs -- they have a conversion kit that can coax 335 HP out of a Mini, which is madness -- they do regular repairs and maintenance.
They make most of their money souping up Minis and BMWs, and selling parts for others to do so, and if you are a car-geek, here's a four-minute video of an endurance race featuring a Mini Cooper and a Corvette. Not to give anything away, but don't bet on the 'vette ...
I talked to the owner, George Mehallick, and when I arrived, he asked a couple of questions, looked under the hood, and made his diagnosis -- probably the seal in the thermostat housing. Since these things are built like Swiss watches, he'd have to take a bunch of crap off to get at it, and it needed an oil change and could use new plug wires -- he showed me why -- it might take a while.
Whatever. I don't want to be in the middle of nowhere and have the temperature gauge peg and red light again. Been a long time since I owned a car upon which I could actually work. As Tom and Ray Magliozzi (The Tappet Brothers) offer on NPR's "Car Talk" Saturday mornings, shade-tree mechanics can't do the electronic diagnostics and modular stuff without a shitload of computer gear, and if you have a new car that needs work, take it to a shop. Fine by me -- when I had to repair stuff because I couldn't afford to pay somebody, I swore if I ever had enough money, I'd hire somebody who knew what they were doing.
That was at eight-thirty a.m.. At three p.m. George called me. All done.
Wow.
Wasn't cheap, of course, but at least it seems to be fixed. Guess I'll find out if it goes clunk while I'm on the road to silat, but failing that, if you have a Mini or a Beamer and you are in the Portland tricounty area, you might want to check this guy out -- when the mechanic opens the hood and starts talking -- and in the case of the Mini, just knowing how to open the hood latch requires specialized knowledge -- if he knows what he is about, you can tell.
This guy knows.
A hint as to his attention to detail, he has a salt-water aquarium in his office, and has in it with the fish, a clam, and he grows his own coral. Tricky stuff, that.