Well I'm thinking that the water pump in my 71 Spider has failed. As I'm not all that mechanically experienced I'd like to get some help on confirming my amateur-wrench diagnosis.
As background, I've been working for about a year on wakening her; she was a 5-year sleeping beauty. Of relevance to this question, she has a rebuilt radiator, new thermostat, new fan, new hoses. Since getting all those, she's been running a nice constant 185 degrees.
Noticed the other day while driving that she'd jumped to 210 degrees. Since I was only few miles from home, I drove her back and then (when she'd cooled a bit) put about 1/2 gallon of distilled water in the radiator.
Nothing leaked out as I put the water in. Next day, drove the car a few miles to a coffee shop, and parked where I could see the car. No obvious leaks when I parked; but after 5 minutes or so, I noticed that she started a small stream of water... which then stopped. I figured that this might be because I don't have a genuine (big enough) overflow bottle and that the overflow had overflowed. After getting home, I topped up the radiator again. Didn't require as much this time.
Today, when I started the car, I noticed a thumping, like the engine moving on its mounts.... something it doesn't usually do.. and it has new Paul Spruell mounts so that's not it. Drove a half mile or so, and noticed a rattling noise, like a loose exhaust... except that all the mounts, front to rear are new. Stopped and popped the hood. Cap was tight, hoses weren't leaking. However the fan wobbles very slightly when I tug on the new fanblade. Oil is bright not milky.
Some water dripping on the sump; a few drops on the shroud.. No visible leaks running. Since I'm close to home, back we go. In the garage, after the car cools a little (she'd never gotten up on temp) I refilled the radiator about 16 oz or so. No immediate leaks were visible. I left, in my other car, and came back about 45 minutes later. There was a puddle of water on the floor of the garage.... Again it seems like the overflow overflowed.
But.... do these symptoms seem like a bad pump? Is there a better or definitive test? Could it be something else? If so, what?
I've read the recent thread on water pumps and the FAQ on replacing one. It seems like any of the usual suppliers' pumps work fine so availabilty and price seem to be the deciding factor on who to order from.