...couldn't find anything obvious wrong with it. As I drove home I realized it was coming from the cooling fan; the noise only happened when the Jeep had been sitting and/or idling, not after it had been moving.
Fan-tastic, thought I (no pun intended, but I'm going with it regardless) and--upon arriving home--proceeded to remove the fan from the engine. But after I got it out, the source of the noise became apparent.
It was the fan shroud: looking at it I saw several places where the fan had bit into the plastic, and there was plastic stuck to corresponding places on the fan blades. (Plastic shroud versus metal fan--fan wins.)
The shroud has been busted from prior to day one of my ownership of the thing. The bottom edge on the passenger side somehow worked its way out of its socket and into the arc traced by the fan blades.
Why does it only make the noise when the Jeep's been sitting? The fan is thermally-clutched: when temps around the fan rise to far, a little bimetal coil changes shape and seals holes inside the fluid-filled clutch pack, which engages the fan.
At low temps the fan probably wasn't turning much, if at all; but at high temps it was full-on and nothing was going to stop it. Hence the noise.
This could have happened just about any time in the past month or so, but I've been using the AC so much the engine fan stayed cool, because the electric fan was on due to the AC being on. (The Jeep has two fans; one is run off the accessory drive and one's electric.)
ANYway: so after discovering this, I decided, Today is the day to replace that shroud and--after arming myself with the names and addresses of several boneyards in the area--hied myself off to see about obtaining the part.
Getting out of the driveway was its own damn project, because first I decided I didn't need to bring the Aluratek (I keep it in my sporran for when I take Mom to the doc) and it needed charging anyway, so I came back inside and attempted to charge it. Except it was sulking and refused to wake up, which is the first time I've had anything like this kind of problem with it. I had to hit the reset button to get it to acknowledge that I'd plugged the damn charger in. Argh etc.
Selected tools, got into the Escort, backed up--Wait, that left front tire is too low, so I had to go back up the driveway, plug in the compressor, wait for it to pump up, and then check the tires. LF didn't register on the air gauge--%#@$*@#%--and the other tires were a bit low. To be extra-special careful I checked the oil, and it was good. (About 1/2 a quart short. Got to do something about that damn leak soon.)
Finally I was able to get out of the driveway. I punched the address into the Garmin Nuvi 205 and let it pick the route, and it was not too bad a route; it got me there.
Paid my $2 admission, let 'em look in my toolbox, and in I went.
Found the Jeep section and spied a Cherokee with a mostly-intact shroud; I figured I'd grab it and then see if there was anything better elsewhere, and had started to remove one of the bolts when I spied a red 1994 Cherokee sitting there, without wheels, waiting to be put on stands, which had an intact fan shroud in it. I wasted no time getting to work.
About fifteen minutes later I had the shroud out, and decided I'd check on the price of the fan itself. Well, they wanted $50 for the fan but $15 for the shroud, so I said "No thanks" on the fan and bought the shroud.
Then I put the toolbox and shroud in the car, drank half a jug of Gatorade, and returned to the boneyard (I'd paid my $2, so I got in free) to look for Escort parts. Also, it had been so long since I was last in a boneyard that I wanted to look around.
...I saw several Cadillac 4.9 V8s around there, but reminded myself that I sold the '86 last year.
I found a couple of 2nd generation Escorts, and for a wonder I found an intact driver's side headlight mount. I went back to my car, grabbed my toolbox, and snagged it. $13 later, it was mine.
I got into the car, finished my jug of Gatorade, and set out for home.
What an odyssey that was. Traffic. Construction. Asshat drivers. A train. More asshats, more construction, and then construction with asshat drivers.
In a bit I'm going out to put the shroud into the Jeep.
* * *
I just checked the price of the thermal clutch for the Jeep's radiator fan: $36 from Advance Auto. So I made the right choice with that radiator fan. Heh.
* * *
Two "recovery summer" links:
Boortz. "Economists were 'shocked' to learn that unemployment claims climbed...." That's because they're all Keynesians, and Keynesians don't know anything about how economics works in the real world.
CNBC. "...[P]rivate hiring rose less than expected...."
Still think the recession is over?
* * *
If you need to know why, just remember that Busting a 7-year-old's lemonade stand is easier than busting the local taco joint.
Another good reason: Portland obviously has too many public health inspectors.
* * *
I'm not looking forward to Saturday. I really hope the air conditioner won't explode.