forester2002s

You say that the original tires are labelled 'M+S'. So they are 'All-Seasons', and would therefore have a slightly more aggressive tread pattern. You could replace them with a NON M+S tire, which should be quieter and smoother. But those would not be suitable for winter/snow conditions (I see that you are in Boston MA). So you would also need snow-tires for the winter months, and run the smoother tires in the summer.

And the shoe-linings can separate (get unglued) from the shoes, after many years. Best to take the brake disk/drum off and inspect the linings.

+1 on battery terminals. I had a similar experience recently, when the instrument-panel gauges started to go wonky. Then engine-power started surging. Then the car died at some traffic-lights. A good samaritan helped me jump-start the car and I was off. It started on its own a couple of times after that, then died again. I found the problem: it was the +ve battery-terminal. It was an aftermarket terminal with a wing-nut for attaching the +ve leads. The battery-clamp was tight, but the wing-nut was loose. So, if I had tested the battery, it would have been OK; ditto for the alternator. The problem was an intermittent fault in the wing-nut connection to the +ve leads. So, check your battery clamps, and wiggle the 12V battery leads.

Your description doesn't match with 'pinging' AKA 'detonation'. It's more likely a mechanical sound. Perhaps from the camshafts? If this was my car, the first thing that I would do is an oil and filter change. Might fix it.

No, all Canadian Subarus get km/h and Celcius displays.

Good post, GD. IIRC, torque tables in machinist's handbooks are for NEW & DRY threads. Add some lube (even just a bit of oily residue), and it will be easier to turn the nut, and the bolt will stretch more, and get closer to failure. Assembling threads using torque values is always problematic. Better to use crush-washers that are designed to measure the actual stretch of a bolt; but not practical for most applications.

That's common to many displays. It's a feature of polarized lenses. You trade the lack of glare from the road and surroundings, for a degraded view of the interior displays. There's no solution except not to use polarized glasses.

I've been using Walmart's own brand of oil for years, ever since Walmart came to town. I've never had an oil-related problem with any of my cars. However, I do frequent oil & filter changes; at least as frequently as recommended, and usually more frequently than that. Just make sure that it has the API 'sunburst' logo, and is the correct viscosity.

Those (small) brake-shoes for the parking-brake last a long time. After all, they don't see much wear as they are normally set when the vehicle is stationary. But over time, the brake-linings can separate (get unglued) from the steel shoe. Never had one lock-up the wheel though.

Those voltage readings look OK, and would suggest no problems with the alternator, nor with the battery. However, could your problem be with the connections between the battery-posts & the battery-clamps? The -ve post seems to always be the one to corrode the worst, and may cause a high-resistance joint. And this could be intermittent. Try this: With the engine running, measure the voltage between the battery-post and the battery-clamp. Should be 0V. Then wiggle the battery-clamp and attached cable. Does the voltage remain steady at 0V? You could also repeat this test by measuring resistance ohms, but first disconnect the other battery-clamp to avoid frying your meter.

Generally speaking, the crush-washers can be re-used several times. If the plug shows no sign of leakage, I wouldn't worry about it.

Could be some debris in the heater-fan. Perhaps a dried leaf hitting the vanes of the fan-cage?

Here are some measurements that I made on the old rings that I recently replaced (I tend to hoard old parts, just in case...): - These are for a 2002 Forester - Subaru O-ring #73039TA020 cross-section dia. 2.2mm; ID 11.0mm - Subaru O-ring #73039TA040 cross-section dia. 2.2mm; ID 16.8mm These are probably accurate to about +/- 0.1mm. A used a digital-caliper, but it's not easy getting a stable reading on the soft rubber O-rings.

Front wheel-bearings deteriorating?

I wonder why a 2016 is for sale? EDIT: It's actually a 2015, so 2-years old, not 1-year old as I had originally misread.

Fuel-filter partially blocked?

Isn't there a rubber-covered plunger-type switch that is depressed when the door closes? If that switch got stuck, the warning light would stay on.

Yes, a C-clamp makes it easy to compress the piston. I use an old brake-pad (reversed) between the 'mushroom' end of the clamp and the piston face.

A oil+filter change sometimes works wonders. Also worth checking the spark-plugs. Could be 'pinging' from one cylinder. Any CELs? (1995? Not OBD yet?)

Some Subaru warning lamps can be replaced with Radio Shack (US) mini-bulb #272-1092. Cost a couple of dollars each. The company that took over Radio Shack in Canada, 'The Source', used to also carry these bulbs, but they've gone upmarket and no longer sell small components like bulbs and switches - too bad! I'm not sure which model years use these mini-bulbs, but my 2002 Forester uses them. It's a lot of work to get the combination-display out, but it gives you access to all of the mini-bulbs.

Sounds like an electrical issue. First things first: - check that the battery is good. Voltage across the battery posts should readabout 12.5V with engine off, and about 14V with engine running. - check that the battery terminal-clamps are tight and not corroded.

Check the oil level first. Take out the (top) plug; oil level should be up to the bottom of the hole. You can put in your small finger to feel inside the diff if the level is slightly below the hole. Use a turkey-basting squeeze-tool to add more oil. Jack up both rear wheels (parking brake off). You won't be able to 'spin' the wheels, but you should be able to turn each wheel by hand. The other wheel will turn in the opposite direction. There should be no noise or grinding from the rear-diff.

Take photos! If the engine is currently running well, then make marks on the old belt and on the timing notches (use a wax pencil, or child's crayola stick - yellow works well). Then take photos of that setup BEFORE removing the old belt. So when installing the new belt, you can refer to the old photo to check tooth-count etc. Only takes a minute.

Wheel bearings? Sometimes causes a 'rumbling' sound, plus steering-wheel shimmy if it's the front bearings.

Or get a used OEM axle from a junk-yard, and reboot it. I'll probably last longer than any aftermarket copy.