Well, I just bought me a 2002 WRX with a bad motor. I know it's not the best way to get into a Subaru, but it was pretty cheap. I spent my whole "toy" fund on the car and towed it to work.
I have worked mainly on Toyotas as far as heavy line goes. I've learned about as much about the boxer motors as I can sitting in a chair, but this vehicle is the first boxer i've done more than an oil change on. I put a clutch in my fiance's 2.5i Impreza but that's about as much as I've done on a Subaru. You may think I know what I'm talking about because of technical sounding words, but that's all just an illusion. I came to this forum to share what I can of this process, and to learn more about these motors from you all. First, the car:
She's a 2002 WRX with 224,000 miles. She has stock wheels, suspension, interior, everything. No performance bolt-on's whatsoever. The body for the most part is very clean and straight. The right rear door and quarter panel have damage due to an accident that happened a while ago by the look of the rust. I'll put a recycled door on it and figure out how to get the quarter pretty again later.
For now, operation "under it's own power" has begun.
The story goes that the timing belt snapped while the engine was running. They put a new belt on and it still wouldn't start due to low compression. That's all I knew when I bought the car. Today I pulled the motor and confirmed that cylinders 1, 2, and 4 are losing air through the exhaust valves. Judging by what I see of the intake valves with the intake manifold off, the intake valves are sealing pretty well. I will be removing the heads and doing a better inspection tomorrow. If the guides don't have any visible damage and valve stems don't wiggle around in there, I think they'll be fine. I might have the seats ground to make sure the new valves seal as good as possible, but I'd like to get away with as little head work as possible. I'll probably also be replacing the piston rings as they have a lot of miles on them. In the process I will be checking the cylinder walls for wear and damage, and checking the connecting rod bearings for wear.
Here's where the scooby experts come in: Should I split the block and check the main bearings? I've never heard this motor run so I don't know what kind of noises it had. I will at least check the free play of the crank but I have no idea how much work it is to split and re-seal that block. Also, do you have any recommendations for a gasket kit? I've disturbed a lot of gaskets, o-rings, crush washers, etc., and I want to make sure the motor goes back together as tight as possible. I've especially heard that upgraded head gaskets are a must with any Subaru. Brand recommendations would be greatly appreciated for piston rings and bearings as well.
Also, do the head bolts need to be replaced any time the heads are pulled? I'm already planning on getting new ones. Should I spend the extra and get ARP bolts?
There is also a disturbing amount of rubber hoses on this motor. Many seem very tricky to get to, so I'd like to replace all of them. Several have split on disassembly due to sitting next to a turbo in Texas heat for 220k+ miles. Is there such a thing as a rubber hose kit that includes pre-formed coolant, fuel, vapor, vacuum, PCV lines? Or do I have to point them out one by one at the dealership?
I have noticed while working on the car that the previous owner seemed to hit a certain point and just start letting the car go. It's really nothing major, just a bunch of little things. I need to replace CV boots on one side, the shift rod (selector shaft?) seal at the tail of the transmission is leaking pretty bad, power steering rack is leaking from the passenger side boot, rear suspension is noisy most likely due to bushings... Most of those I can address once I get the car running and can drive it around. One thing I have to address at this time is the clutch. The rivets have been hitting the flywheel and made a very slight groove in the surface. I'm 90% certain it can be machined out. Does anyone have a recommendation for a clutch kit to throw in there? Most likely I'll be driving it as a commuter/autocross/miscellaneous fun gravel road adventure vehicle. The clutch doesn't need to hold a possible future build or take 5k rpm clutch dumps, but I would like a rather sturdy setup for regular spirited driving. 'nother words I'm never going to expect better than 15 mpg driving this WRX.
I believe that's it for now. Sorry I don't have any pictures of the car. Tomorrow if I remember to bring my camera i'll take some engine destruction pictures to show around.
If you made it this far, kudos! Thank you for reading my random and somewhat excited ramblings. I look forward to thoughts and input from more experienced Subaru folks.