1 Lucky Texan

wheel bearing/hub or axle problem? measure temps at the hubs after a highway run. If one is consistently warmer by - maybe 30-50* or ??? , inspect everything at that corner - even the parking brake shoes inside the rear rotors.

08 probably has HBAs right? - easy to swap so, maybe do both sides as mentioned above? did you try rocking/lifting the wheel in the 12 - 6 O'clock direction? I found a bad, noiseless, rear bearing like that once. The good side didn't move, the bad one moved maybe 2mm. bad bearings can be hard to find.

have you considered a full window tint job? ceramic films are really nice. also, take a look at some of the options they have for baby/toddler sun protection in cars.

swapping front tires with the rear pair should eliminate/confirm a tire or bent rim problem. u-joints and carrier bearing might be worth inspecting.

is the transmission pan dented? Any evidence of rodents chewing on cables? anyway, you could start a new thread asking for a shop recommendation near haverhill, someone may be able to direct you to a good Subaru mechanic.

smaller diameter tire creates greater difference in axle rotation so, center diff is slipping even less than before. no question now - center diff failure.

just looked at a map y'all could meet-up in Bridgeport in what - 30 minutes? have lunch, diagnose a Subaru - BAM!, problem solved! lol!

^^^ very generous offer right there!

some folks have had odd breaks in springs - basically looks OK when static, but separates on extension/bump. if you can't find anything, ask for a shop suggestion in a new thread - maybe someone will suggest a good mechanic near Elkins. Take them for a ride to demonstrate the noise.

I think there is a clip on the end of a wire inside the back - could be something different has happened to your seat but, people have found ways to fix the lumbar wire. probably other help on-line if you search but, check these out; http://www.subaruoutback.org/forums/104-gen-4-2010-2014/60425-lumbar-support-explosion.html

yeah, bearing assemblies didn't come in umtil 2005 or so, depending on model. there are 'hub tamers' and various kits you can buy or rent from some parts stores. an intermediate approach would be to take your new bearings, hub if needed, and your old knuckle to a shop and have them press-out old, then press-in new, bearings.

maybe a valve is tight? right on the edge? vacuum gauge might show it.

that's a tie rod boot on the steering rack, good idea to replace that. if a caliper isn't sliding, the inner pad could be down to the metal so, get those wheels off soon. should be able to get a L wrench or a 4-way at the car parts store.

swap front pair of tires with the rear tires, monitor for change in symptoms. have the front-end inspected - sway bar, mounts and endlinks, steering rack bushings, tie rod ends, etc. was any work done or wrecks occurred before you noticed this problem? you could ask in a new thread for a shop recommendation near you in Sandy - someone may know a good independent mech. If possible, take the mechanic for a ride prepared to demonstrate the problem.

all tires the same brand/model/size and close in wear? they must be. does the car jerk or feel like it is resisting tight maneuvers in parking lots? can it idle (or very little gas) thru tight circles on dry pavement smoothly? have the brakes been well maintained?

man, you are thorough - way ahead of me and my w.a.g.s I had to reflash my ecu to kill 14 codes for stuck (closed thank god) aircut valves. (but, 06 WRX)

nothing wrong with inspecting brakes - but the advice about it 'possibly' being surface rust is good. I have seen light rust spots develop on my WRX's rotors in 8 hours parked at work!

I probably either; A. wouldn't worry about it at all. or, B. would wrap a few layers of tape around the cable at that point and zip-tie the cable (snug enough to limit movement, but not excessively tight) to the stud/bracket or something in that area to limit movement.

any sign AT ALL that parts have been pulled-off and re-installed? does a 13 still have aircut valves? kinda sounds like that air pump and those valves which are active at start-up. does a 13 have TGVs? is it possible the vane for cyl 4 could have a problem/be loose? also, is there any possibility the previous owner tried to flash a tune onto the ECU and the process was corrupted? You may need to find a 'stock' flash image to put into it. those are my guesses.

could be IACV-related, a little leak in the hose (i THINK 98 has a hose) or gummy valve - maybe even a dirty throttlebody? MAF cleaning could be a good idea too.

well, 1 & 3 do share a coil so, that was a good guess. did the wire boots on the plugs have oil on them? how did the old plugs look? also, have you checked for slipped crank or cam timing?

maybe pull the thermostat and test in hot water on the stove, make sure it opens smoothly at around 170 - 175* or so.

not sure - but do a search and read up. you def. want the Subaru turbo engine gasket s(or possibly one or 2 aftermarket) Multi layer Steel gaskets. And heads need light resurfacing. Probably do not want to do it on an engine that has had several overheating events or been severely overheated - possible bearing failure after expensive work would be a bummer. Some folks get junkyard engines, often low miles, and rebuild heads and timing belt system to swap in. there are discussions here, over at subaruoutback.org , probably some youtube videos, etc. for diy. I have never done it.

3 & 4 share a coil, maybe it failed? might also try a vacuum test - symptoms similar to clogged exhaust I guess.

diy? decent kits start in the low $100s . hiring it done, figure about $80-$100 and hour and - I dunno, 2-3 hour labor charge(3 is definitely high-side for an experienced mech. i think, depending on what other minor service is combined with the TB I guess?)? some places may get a profit on parts so - $400 ? call around, a good shop should be able to give a quote +/- 10-15% . if you post your city in a new thread asking for a shop, maybe someone will have a recommendation. if you suspect the car has a HG problem though, you need to confirm before putting good parts on it. I read a lot, but have much less experience than many folks here - I did the TB service on my WRX last year - found the toothed idler very loose, noisy and a little wobbly. about 8.5 years, but less than 60K miles! The pulleys lose their grease over time and can seize or fall apart. My belt tlooked great but 2 pulleys were going bad. Would the car have made it to 105K like the book says? - I doubt it very much from what I found. Glad I did the service. You also get a chance to look for oil weeping oil past cam/crank seals. Good time to throw new accessory belts on, change the coolant, put in a new thermostat.