GeneralDisorder

Yes. One of the nice features of the Subaru layout. It's no trouble at all. GD

Check for vacuum leaks. Make sure the intake manifold and heads were cleaned of all old intake manifold gasket residue. GD

Can you shift it through the gears without putting the clutch in or with very light pedal pressure? The smell sure sounds like it's clutch related. GD

The 770 gasket is what we always order. The coolant passage mis match doesn't matter in the slightest. The recommended dealer gasket doesn't match up either. In fact if you really take a look at gaskets and cylinder heads almost none of the Subaru combinations actually match up entirely. End of the day it make no difference at all. You guys are way over thinking this. GD

The CVT is a much better transmission than the manual. At this stage of the game manual transmissions are worse on fuel economy, maintenance, and longevity. Their only purpose is for people who enjoy shifting for no actual benefit other than perception of sportiness or misconceptions about economy, etc. Truth is the CVT with a 16 year old driver will beat you in the 1/4 mile every time and do it while getting better MPG and last twice as long. No clutch to wear out, no syncros to grind.... etc. GD

It was already an interference engine with the 96 pistons. And yes it will be interference with the 97 to 99 pistons as well. This isn't important if it's put together correctly as EJ timing belts don't break unless (again) you do something really stupid or use cheap components. Trust me on this - you want factory used pistons with skirt knurling and Japanese rings. I've been through this hundreds of times. Literally. Hundreds.... yeah. Bore guage is a waste of time. The bores are tapered, hour glassed, and probably a bit ovaled. None of this matters *in practice* They are factory sized because no one would buy oversized pistons from the dealer for 96 specific and there is no aftermarket on those. You can tell by that alone - also it's obvious the fellow that built it didn't have two brain cells to rub together or he would have not used 96 flat top pistons. What matters is fitting the pistons nice and tight, and new rings. And NOT HONING. You're way, way, way over thinking this situation. I've already done the decades of experience for you here. Just put it together the way I tell you and everything will be ok. Trust me don't buy the aftermarket pistons they will slap like MAD in those used bores. It's a waste of money. Skirt knurling is the way to prevent that and keep the pistons square in the bore and the oil consumption under control. GD

That engine is notorious for oil consumption due to oil control ring clogging. It's probably got one or more scuffed piston skirts from this as well and needs the pistons knurled and the rings replaced. Very typical. What you hear is most likely piston slap that diminishes as the piston expands to fill the bore. GD

For $35 you can download all the manuals you like for 72 hours from the Subaru technical documents server: https://techinfo.subaru.com/index.html GD

Well yes we have done that several times. I would get yourself a service manual and review the procedure. It's about 8 to 10 hours to pull a dash and put it back in to replace (from example) a heater core. GD

I would be willing to bet my 2000 Suzuki Swift (Geo Metro) 1.3, 5 speed manual, would smoke any EA81. In fact I would give it odds against an EJ22 swapped Brat. It's actually surprisingly fast. GD

Yes replace the cap. If the radiator is more than 10 years old just get a new one. Get a Koyo radiator and a good Japanese cap. Get the thermostat from the dealer or if you can find it, a Tama brand one. GD

Drain the front and rear diff gear oil and check how much metal is on the magnets. If there's a giant forest of shavings you have found the culprit - almost always a pinion bearing. GD

You need a hose and an o-ring for the PS. No big deal. The roaring noise is a wheel bearing. You won't feel it by turning the wheel and checking for play. You need to stethoscope it on a lift at speed. These are problems that all Subaru's going back to 99 had. Talk about premature bearing failure - ask the early Forester owners, or anyone that owned an SVX. The old PS pumps leaked like crazy from the seals. That goes back to 90 or earlier. They all do it. There is no difference in quality between the cars. You people have anecdotal evidence based on one or two cars and their specific failures. I work on hundreds - probably in the neighborhood of up to 100 a month. Almost exclusively Subaru. And seriously - get off it about plastics. They are here to stay. I just replaced a broken plastic heater control on an '86 Subaru GL with 130k on it. I also broke about a million plastic bits doing a heater core on a 1990 Corvette last week. Plastic is here to stay and has been for *quite* some time. And some of it is quite good actually - glass fiber reinforced ABS and Nylon has higher tensile strength than Aluminum in some cases and for some applications has greatly enhanced thermodynamic properties. GD

Do not hone the cylinders. Don't even measure them. Just install a set of 97 to 99 pistons - I may have a used set I can sell you. I can get Japanese rings for you also. It would likely be about $150 shipped for a used set of pistons and new rings. These would be factory pistons and the rings we use on all our builds. 100% of my engines have zero oil consumption. If you like for an additional $80 I'll knurl the piston skirts also. Those aftermarket pistons will slap like crazy - that ebay stuff is Chinese. Read this: http://www.snowvalley.20m.com/bikes/dnthone.htm GD

Huge difference in compression ratio - 10.6 vs 12.5 or so. You will break one of the other pistons and it will run rough due to that cylinder being about 50-60 psi low. Most of the time the pistons are sold in sets for pretty cheap. Same with the rings. For the little extra work it would be really stupid to not do them all. Do not touch the cylinders!!! GD

You have to replace all 4. For one you can't buy those 96 specific pistons and for two the compression ratio IS TOO HIGH. It will just happen again. Trust me here - replacing that one piston is one going to result in serious frustration and more engine damage. Unless you have access to 140 octane leaded race fuel. GD

If the turbo failed due to lack of oil chances are you will need a whole engine soon. The issue is that the oil is shared between the turbo and the engine so when the turbo fails the metal from this failure goes directly into the oil pan and is sucked up into the engine and can ruin the bearings in the engine as well. You need to pull the oil pan, cut open the oil filter, and check for contamination. You can't be certain that damage wasn't done just from the loss of oil pressure, and these engines are also prone to oil pickup tube cracks, and ring landing failures so if it were at my shop we would be recommending at minimum a turbo rebuild (~$600), and a new crank, bearings, forged pistons, and a Killer B pickup tube. Typically a build such as this runs between $5,000 and $8,000 depending on what upgrades get thrown into the mix. There are lots of hoses that will be shot from age and heat, it will probably need a new turbo inlet, and there are many opportunities for upgrades and power adders as well. Even if you just get a new short block from Subaru and drop it in you are looking at $5,000 for parts, labor, etc. If you try to cut corners you may as well sell it as soon as it's running again because half measures don't work for long with the EJ25 turbo models. They are too complex and you need a good Subaru performance shop that knows what they are doing or you will leave with a time bomb. It may not look like it, but the engine is identical to an STI - just with a smaller turbo. You own, effectively, a 300 HP turbocharged, AWD rally car that's been slightly detuned and had a body styling change. Make no mistake this is just as expensive to work on as the $35k 2016 Hyperblue STI we put pistons and turbo upgrade on last week. GD

88 hatch is an EA81 and those are all metal and dual core by default. Also not applicable to the thread question. GD

Valve cover gasket is about as "major" as a bad paper cut. And a heck of a lot cheaper than a new OEM coil pack. Which is what it sounds like you need. GD

3 and 4 share one side of the coil pack. I would start by looking at that. GD

Yep. Get some 97 to 99 pistons. That will drop your CR to about 10.6

If the head gaskets haven't been done, then you will want to address that. Pull the engine and do HG's, rings, knurl pistons, and do complete reseal and timing components. Replace oil pump with a 10mm. GD

With EJ engines, as long as you adhere to the maintenance guidelines the chances of a timing belt failure are extremely remote. It's a complete non-issue that people cling to with no experience out of unfounded fears and outdated beliefs. GD

Yes that schematic will do the job. Nice work. Fuses are there to protect the wiring. Use appropriate fuses for the wiring size. Use the same wiring size as the factory solenoid wire. It's most likely 10 or 12 AWG so size your fusing acordingly. A 20a fuse should be sufficient to protect the wiring from outright catching fire in a dead short situation. GD

They are all the same these little generic cube relays - they all use the Bosch standard Here's a cute one with pigtail: https://www.amazon.com/gp/aw/d/B01LYW0D55?psc=1 GD