davebugs

I remember about the 99 Forester SOHC's but forget about the Impreza's. The true way to tell IMO is look at where the wireharness is at the eng/trans on the passenger side. If one has 3 connectors and the other has 2 it won't work. Atleast not easily.

I just reread your post. The flexplate needs to stay with the trans. May not HAVE TO but a good practice. I'm having trouble figuring out what you are replacing - but it's just me.

A little patience, the flexplate off the 2.5, some rubber hose rerouting. Search here, very common swap. Welcome to the USMB!

They usually aren't as picky. But following the burping for the 2.5 certainly won't hurt. OEM thermostat? Partly I ask due to quality, partly I ask because the OEM one is so much larger that folks tend to notice/question what they are doing and are less likely to get it in backwards.

Search here for "burp" or "burping" there is even a video. Basically pull off the rad hose at the WP, reattach, fill engine with coolant through upper hose, attach it, top off rad, leave cap off. But search. Often I'll run whatever wheel is closest the rad cap up on a rhino ramp to make that the high point in the cooling system. 2.5's can be tough toburp.

The 99 was the last of the DOHC 2.5's with the internal HG leak. Generally in 2000 they started with 2.5 SOHC's that leak externally. You can link a SOHC along for a while without really hurting it if you pay attention.

And if you open radiator cap after it cools you don't see coolant in the rad? Classic HG's on a Subaru 2.5. Depending on how many heat cycles you've done to it it might be worth fixing. If not it's 2.2 time. Because all the JY 2.5's are gonna have the same problem as yours. And welcome to the USMB!

Yea. The first time that happens it's like WTF? It's easy to miss it not being connected. Glad it was simple to fix.

STOP! In my experoence rarely will the typical 2.5 DOHC HG cause much of a compression issue. Infact that along with not making a cloud of white smoke is how most mechanics miss the classic Subaru HG problem. Please update your profile with a useful location. Not saying it may not be worth buying but it may NOT be a HG problem, or not JUST a HG probelm. If it's been overheated repeatedly it's junk - think 2.2 swap. Don't spend time or money into that 2.5 because it's just a matter of time until the rod bearings go. And FYI I'd pay about 1k for that car around here mostly depending on the rust.

If anyone is coming from the West and needs a garage for repairs(lift, tools,air tools, welder, torches, even a lot of 95-99 Legacy parts if not scrapped by then, etc.), lodging on the floor(I have 2 empty bedrooms upstairs), etc PM me. NO pets. NO stereo competitions - my neighbors and I get along and I'd like to keep it that way. Ample parking I'll probably be here that weekend and won't be in good enough shape to walk all over the Carlisle Fairgrounds so I won't be attending. I'm about 3 hours away see link: http://maps.yahoo.com/#q1=Carlisle%2C+PA&q2=Apollo%2C+PA++15613&lat=38.44777174658948&lon=-95.23234605789184&zoom=8&mvt=m&trf=0

Check the stiff foot long hose on the passenger side that goes the the throttle body basically from under the air filter cover for lack of a better explanation. It's about an inch round. Often it looks like it's on and it isn't. And you can pull your hair out looking for the problem. It's NOT on top. And welcome to the USMB!!

That lower ATF line is fun. That ATF line, the 14mm nut above the drivers axle and TC bolts are probably the most difficult parts of pulling these engines - and really not that bad at all. As pointed out I try and remove just fans if doing just timing belt, idlers and seals. But if you're doing the water pump it's easier to remove the whole assy and give yourself room. I always put cardboard or paneling at the radiator to make sure I don't accidentally hit it when pulling seals or with tools. Here in the rust belt those fan to rad bolts snap off a lot even though they are going into plastic and then that's just something else that needs fixing.

Same bolt pattern as MKIV VW's (lets say 95.5-2005) and I believe late 90's cavaliers. At 2005.5 they went to 5x112's. Earlier years may work though but a lot of them are 4 bolt. I KNOW they are the same on a 97 Legacy GT as an 01 VW Golf. Offset must be close as well because there were no issues.

Or go to their website theimportexperts.com and call the 800#. Ask them to check that it isn't cheaper on Ebay. I believe often the owner runs Ebay specials and doesn't let the folks that answer the phone know. I have them throw in the accessory belts too - dirt cheap. ANd as I've stated the last kit I got for a friend the cam/crank seals looked the same as OEM. Also their WP gasket was rubber coated metal.

I have seen NAPA's do this years ago with Martin Senior(?) paints laquer and enamel. I have an antique VW bus that is a weird tan color. And doesn't come close to matching the only tan they used in 71 & 72. I removed the fuel filler door and took it to one of those places that puts it under a machine and prints out a formula to mix paint by. I haven't tried it yet. But an auto body supplies company can probably do this. It's just like Lowes has for latex paint.

Are you doing HG's idlers, timing belt, etc, etc, before installing the used engine? Now is the time.

I have used Seafoam very successfully fo rmostly "catalyst effeciency" codes. But I wouldn't dump it into the crankcase. Fed through a vacuum line for above issues yes. In fuel as a stabilizer and to help with above problem yes. Into crankcase no.

As I stated in post#6 in this thread Marvel Mystery Oil (MMO) seems to work very well in Subaru's. I'd run it a little while then change the oil. Anything from 10 to a couple hundred miles. When I do a HG job or install a JY 2.2 often it's a quart of MMO and a "spirited drive" after the car is warmed up. Then drain the oil/MMO, new filter and fresh oil. I'd never used MMO before folks here recommended it. And it does really seem to work on Subaru's.

I have a 7/8 open/box I use for this. Much better success with it than any of the 3 other O2 sensor socket styles that I already own. Just to reaffirm what others have said in this thread.

Start soaking it down now.

Welcome to USMB. On a 2.5 with those miles I'd start with OEM plug wires, and perhaps new NGK plugs while the wires are off. Were the wires installed something the local parts place had (and made a huge markup on) or OEM some have luck I believe with NGK wires. But other than that they usually don't work too well. Knowing the P code(s) would help too. An alternator check may be worth the time. When a Subaru alternator starts to go a few other idiot lights light up (ABS and something else unrelated - I forget), and you loose top end. I don't recall them missing but they do loose top end. Then when you let it set the battery rejuvinates itself and you can drive the car again, and the top end keeps getting lower and lower again. So real P codes, have alt checked for kicks if you can as more of a longshot. We're gonna know what specific plugs were installed too.

As pointed out propably won't help - you need to adjust valves. That said I'm not a big fan of Seafoam in the oil. In the fuel or through a vacuum line yes. I've had much better luck with MMO removing gunk abd making Subaru engines more quiet.

Read around here a bit. A 95 2.2 from an AUTO(with EGR) is the most common swap inplace of a 2.5. Very easy and reliable.

Several folks here have has issues with Mizo kits. Only troubles I've ever had with theimportexterts weren't with the kits and easily remedied and excellent to work with. For instance one time I needed VC gaskets and they sent for SOHC and I needed DOHC - that kinda stuff. Just sayin for future folks who may read this. So being happy with theimportexperts I"ve never needed to try anyone else but members seem to have more issues with Mizu.

I wouldn't want my neice stranded for a couple hundred bucks. Get a kit (I use theimportexperts) and do the seals, idlers, waterpump, accessory belts, etc and be done with it. It's still an old car, but you'll have done all that you can and it didn't cost much.