1 Lucky Texan

any recent charging of the a/c system?

there's likely 3-4 problems that might lead to this behavior - and I am certainly no expert. when you say it seems to work after being off "for a bit" - would that be long enough for ice to melt if the coil were frozen-over? has the cabin air filter been serviced? any correlation with the problem showing-up when stopped or in extremely slow traffic? any large amounts of red dust near the compressor? if you have lost 'some' refrigerant, the pressure switch that is supposed to protect the system may be right at the edge of triggering - such that it is intermittent. a pro can check things out with some gauges, vacuum the system and otherwise check for leaks and a proper charge. Some people have done well attacking a/c problems on their own so, you might read here; http://www.subaruoutback.org/forums/99-do-yourself-illustrated-guides/43428-diy-c-air-conditioning-leak-refrigerant-repair-5-less-15-minutes-less.html

compression test might be in order. you could also try switching to a 'high mileage' oil.

scan for codes? some folks have had crank position sensors intermittently fail at temp.

well, if everything is normal, disconnecting should immediately stop cycling the fans and relays and solenoids, etc.

it isn't clear to me but, you know those green test connectors should be unplugged right?

is there spring in the relief valve that could be broken? I read of an RS owner that found his OPRV stuck open. anyway - good luck with it

can you grind down the outside of the special socket enough to both fit and still work?

or, get a lower-miles 2.5 engine from a wreck (probably running OK when it crashed) and pull the heads - resurface and reinstall with multilayer steel/turbo gaskets - new timing belt system components, and drive for another 200K+ DOH! - beat by seconds!

check the new pump for cap/o-ring problem.

double check the oil pick-up - look here; http://photos.killerbmotorsport.com/GalleryThumbnails.aspx?gallery=244340 any chance PCV and breather hoses have been misrouted? I read one thread once where that messed with oil pressure readings.

any progress on this?

any progress on this?

any progress on this?

^^^ HAHAHAHA!!! uh, funny, but, really glad there were no injuries.

vacuum could also demonstrate there's still a leak that needs to be addressed - but, gg's experience is that, the majority of time, a vacuum session is unneeded. I suspect it may depend on factors like ;how long and how - 'severely' - the system may have been exposed to the atmosphere, catch it quickly and there' not much moisture inside. probably the older a system is, the more o-rings that may need to be addressed. Also, if the system has had to be re-charged multiple times, it may have a little more moisture in it, etc.

wait - is the trans a 5spd or automatic? NON-synthetic GL-5 for 5spd, Dex III as said for auto. , any GL-5 will work for rear diff, check the manual for viscosity. has the timing belt been changed? it should have been at 105K - maybe it has slipped and is causing the problem you have now?

lots of swap info at nasioc.com - you can make any project work with enough time and money. H6 , diesel, supercharger, etc. but, it could actually be easier - and maybe not much more expensive, to get 2 wrecked WRXes, one wrecked in the front, one wrecked in the rear, build one good car and sell any usable leftover parts. Or just carefully shop for a WRX that hasn't been abused.You get matching final drive ratios, a wiring harness that works with the ECU, dash and rest of the car, a transmission and drivetrain built for the power, less worn-out and fatigued rubber parts, the ability to tune the ECU for power, lots of aftermarket suspension and other go-fast bits. (I'd probably recommend an 06 or 07, but almost any of them are gonna be a much easier and maybe not much more expensive than the swap.)

I'm not certain, but that tensioner bracket 'may' have been superseded by a new design anyway - pretty sure it was on later WRX engines anyway. new bracket from an on-line dealer might be an option, check fredbeansparts.com , subarugenuineparts.com , etc.

sounds like your compressor is past any easy fixes - but there's still some good reading here;http://www.subaruoutback.org/forums/99-do-yourself-illustrated-guides/43428-diy-c-air-conditioning-leak-refrigerant-repair-5-less-15-minutes-less.html?highlight=diy+compressor+o-rings+valve

i THINK rod knock would almost always be worse as you rev higher. anyone? but I don't want to think a new tensioner is bad letting the belt flop around. There is a video at youtube showing a guy using a screwdriver on the tensioner to smooth-out belt travel and stop a knocking sound. piston slap? seems unlikely but, maybe possible in a JDM ej25? like wtdash - I have read that, since Japanese drivers know that stringent emissions testing is likely gonna force them into a new car quickly, they tend to not do proper maintenance and many of those front clip motors are in bad shape. Not sure if it's a universal truth though. anyway, try to get pics of the problems you found if you still have pieces of the JDM motor and its cut wires and sealant smeared everywhere. just CYA.

well, non-functioning or intermittent fan could be the cause of overheating - particularly if the overheat events seemed limited to stops or very slow driving.

I grease those slots - some people have found some aftermarket pads that needed the pad backplate filed/ground a little on those ears - maybe flashing or paint causes them to stick a little. Doesn't seem like oversize ears would lead to a rattle....? whne you pulled the old pads out - were they evenly worn ; inside-to-outside pad, and 'toe-to-heel' on individual pads? just seems like your noise might be something like heat shield now - or unrelated to any recent service like the brakes. maybe check that a CV boot band hasn't come loose? Any chance a sway bay endlink is loose?

after which service did it begin?

NASIOC has such a list, but it may be highly Impreza-weighted.