flat4_5spd Reader
5/23/24 10:26 p.m.

So, a couple of weeks ago I was merging on to I-294 and hammering on my '08 Legacy pretty hard in 3rd.  All of a sudden, I was faced with an engine that

was clearly running on three cylinders and a blinking CEL. I also had a phone with a dying battery, no charging cable,  and no idea where to exit to turn around, but that's not important right now.

Limped it home, did a compression check and got this: 

Nada in cylinder #1. 
Borrowed a leakdown tester from my neighbor and heard hissing out the exhaust and my air compressor couldn't provide enough volume to build more than 20psi in the cylinder. Bought a borescope,  couldn't really see too much, but the piston didn't seem to have a hole in it or anything. I concluded burned valve, bent valve, bad valve seat.   I contemplated buying a used head to drop on, but decided to order some remanned ones. They have been sitting in our dining room for a couple of weeks now while the rest of the parts and tools were tricking in,  so I decided to get on with the job. 

Pulled off the front cat 

Peered in the exhaust ports with the borescope:

Kind of crusty but not too bad:



That is a slipped-ass valve guide.  Evidently not unknown on these EJ25s. 


flat4_5spd Reader
5/23/24 10:34 p.m.

Continuing with more reasonably sized photos, sorry. 

Got some help from my son pulling stuff apart


Got the alternator, plenum, ps pump, rad fans, airbox out of the way. Started soaking the EGR tube with penetrating oil. Disconnected various sensors as needed. 

Ran out of time but got this far.


OK, I guess I need to work harder at resizing photos. I adjust the size in preview, they look tiny but when the post goes live they're giant. Hmm. 

flat4_5spd Reader
5/24/24 1:36 p.m.

Day 2.  The weather report is calling for 75mph winds, possibly hail so I called things early.  My wife is repeatedly saying "storms a brewin' " in a fake Maine accent. 

Crank pulley, T-belt and needed tensioners/idlers pulled off. 


The dreaded EGR tube came off with very little drama


What do you folks make of this slight weeping on my tensioner? It's just a little wet on the top. It's maybe 4 years old and either OEM or Aisin, I can't remember. 




adam525i GRM+ Memberand SuperDork
5/25/24 10:07 a.m.

Don't put new heads on with a leaking timing belt tensioner! I'd probably just buy the whole timing belt/water pump/t-stat kit if you are this far in unless it is pretty fresh. If the car is a stick I'd also toss a throw-out bearing in it even if everything with the clutch is fine.

I'm looking at something similar in my 07 Legacy Wagon, I finally realized the chirping I've been hearing at idle is my throw out bearing so I was making plans to deal with that. This past week the car has started pushing a bit of coolant on longer, hot drives and the system is still slightly pressurized in the morning when the car has sat overnight so I'll add headgaskets to my list. My timing belt is all new this spring so I'll reuse that. I just need to decide on a new clutch/pressure plate as it still bites really nice.

At least these cars are easy to work on and pop the motor out to do these jobs.

flat4_5spd Reader
5/27/24 8:17 p.m.

Adam 525i- with the belt tensioner, my thinking was that it's only 4 years old with about 30K miles on it. Had the car not chucked a valve guide, I would have been motoring along without a concern in the world about it. (Also, the car is a stick, so it's got that extra timing belt guide around the crank pulley that makes it really hard for it to jump time..) But, I thought about it and you're right. I'm ordering a fresh tensioner. All the idler pulleys and the T-belt are the same 4 yo/30K miles, so they're staying.  Also, I'm doing this job in situ. It would make more sense to pull the engine, but I don't have access to a garage or a hoist right now. 


The lower shoulder bolts on the valve cover were a BEAR. I tried everything- heated the valve cover and bolt up with a MAPP gas torch, penetrating oil etc. I was eventually able to get 2/3 of the lower bolts out, but the center one wouldn't budge. I took all the other bolts out and whacked the valve cover around a little, hoping that the movement would break the bond between the bolt and the valve cover. No dice. I ground the entire head of the bolt off, hoping that I could gently pry the valve cover off. No dice. This was the only thing that worked. 

Finally got the pass side head off

Cleaning it up, trying to keep the crud out of the cylinders: 

Got the new head on the pass side. There were some irregularities with the torquing procedure (namely, I followed the loosening torquing sequence from the disassembly procedure for the first pass "gasket crushing" procedure rather than the assembly sequence. ) After that, you back the bolts off 180 deg 2X and then torque in three steps, two passes of torquing to an angle and then some extra angle torquing on the center two bolts.  I did all the post-gasket crushing torquing and angling in the proper sequence, so I hope I'm OK. Not totally happy with the surface of the block either, but I did my best to clean everything up. 

Lost Sunday due to bad weather and a case of "I am to old for this and need a break." 


Memorial day: 

Got the driver's side head off this AM. 

Transfering the "I can't believe it's not VTEC" valve timing module to the rebuilt head. 

Mostly back together. Intake manifold was gummy as hell inside, I did what I could to improve things. Also cleaned up the PCV valve which was pretty sluggish due to gum. 


I've got to get that T belt tensioner, get some fresh studs for the cyl head/cat converter fixings, couple bits and bobs and we'll put it together and see what happens. Also have to adjust the valves once I have the timing belt hung- but wanted to put the valve covers on in the meantime to keep grit and weather out of the works. 


wvumtnbkr GRM+ Memberand UltimaDork
5/27/24 8:40 p.m.

So,since you have the old head off...  what was the issue?

adam525i GRM+ Memberand SuperDork
5/27/24 9:46 p.m.
wvumtnbkr said:

So,since you have the old head off...  what was the issue?

It pushed a valve seat out, you can see it in the last pic of his first post

flat4_5spd Reader
5/28/24 8:12 a.m.

It was an exhaust valve guide that drifted loose from the head preventing the valve from closing.  You can see the difference between the two borescope photos showing the backside of the valves.  In the photo of the first exhaust valve you can see just the tapered tip of the guide, the 2nd pic of the valve next to it, there's more of the guide outside of the head than inside it!  It's an uncommon, but known issue with these EJ25s. Supposedly, the different expansion coefficient between the aluminum head and the steel guides comes into play. Also, the valve stem seals fail or come loose, carbon builds up on the valve stem and makes it bind, valve guide hammers up and down in the head. 



wvumtnbkr GRM+ Memberand UltimaDork
5/28/24 8:33 a.m.

Ah, I missed that.   For some reason I thought it was sticking OUT of the combustion chamber, not into it.  Seems silly looking at it again.

flat4_5spd Reader
5/29/24 11:22 p.m.

Should have it back together and hopefully running tomorrow. Hung the timing belt yesterday, adjusted the valves tonight after work. (Cylinder head rebuilder specifically states to do it after heads are installed...kind of  a pain to do in car. If I had it to do again, I'd probably pre-adjust them and then check and only readjust as needed on the car ) Adjusting the valves seems to have resolved what felt like a worrying lack of compression on all but one cylinder when spinning the engine over with a breaker bar- some of the valves on the new heads were adjusted to zero clearance which didn't allow them to close.   I spun it over on the starter tonight post adjustment and it sounds like it should- not lopey. 

Given the sub-optimal taking-the- engine-apart-outside conditions I was working in, I'm sure there are at least some gritty contaminants in the oil and on the various exposed engine surfaces. (Also, the car was driven running on 3 cyl for a bit, so there's definitely some fuel dilution of the oil too.)  Change the oil before firing it for the first time? Run it for a few minutes to collect any loose grit , then change the oil? Or, change before running it and AND after running it for a little bit.  What do you think?



akylekoz UltraDork
5/30/24 6:53 a.m.

I knew what your problem was right away, not because it happened to me however.  My Aunt gave me a Legacy Outback that she ran out of oil, bottom end seized up, so I decided to sell the heads.  One guy told me the heads were junk because he could see the guides and would not buy them.  I checked and all guides were visible but all the same height, none had slipped.  The next guy in line was tickled to get all of the leftover parts, and two good heads for cheap.

flat4_5spd Reader
5/31/24 2:38 p.m.

I thought yesterday was going to be be the big day, but no dice. Worked until about 8:30, drained oil and attempted to refill it, only to find oil drizzling out of the bottom of the driver's side valve cover  (The oil filler goes into the top of that valve cover)   I figured that probably somehow the valve cover gasket was on wonky... even with the motor mounts unbolted and the engine raised on a hack, it's hard to get the covers back on with the frame rails being RIGHT THERE. I was really disheartened, thinking that I would have to undo the motor mounts, jack up the engine, again etc to get the covers off.  Fortunately, I  was able to loosen the valve cover and get it off far enough that I could reach in to put the valve cover gasket in the groove in the valve cover. All is good.  I do suspect that I may have created a little leak in the crankcase due to carelessly jacking the engine. 

And the result: Running EJ 25



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