So I'm finally tackling this project after months of procrastination, after grabbing it months ago. All casual indications lead to leaky head gaskets, apparently a notorious issue in the DOHC 2.5L EJ25 engine. It runs beautifully and drives great, but after 10-15 minutes of driving suddenly the temperature will spike dramatically. Then it will go back to normal, then do it again, etc.


While there are people online who say you can do this with the engine in the car, I figure it'll be easier to pull it since I have a hoist and stand already.




It Begins.



Radiator, Air Box, various other things removed.


Hopefully I can get it out and on a stand today. We shall see.

4/24/2012 4:24:37 PM

not a problem to get it out with a hoist and onto a stand in a couple of hours by yourself

I've never done head gaskets, myself, but it doesn't look too difficult.

Although, there is tons of help on http://www.nasioc.com

4/24/2012 4:31:52 PM

Pulling that motor is easy as pie with a hoist. Hardest part is breaking the bellhousing bolts.

You can leave the A/C and power steering pump with the car.

I like to coat those head gaskets with copper spray...I treat them like a turbo/high compression setup. Heads/block should be resurfaced but I've had success with just cleaning them with the fine white roloc bristle discs, assuming no warpage. So, let me rephrase, if you have every surface machined, install the gaskets dry.

I think subaru head bolts are reusable...never really got a straight answer on that one. None of the dealers I talked to replace them. I've reused them, also, with no problem.

[Edited on April 24, 2012 at 5:00 PM. Reason : .]

4/24/2012 4:41:02 PM

too late on the AC

but yeah, on the PS, don't unhook it

4/24/2012 4:45:35 PM

i hope you did a leak-down test or checked for air bubbles first

personally, i'd leave the engine in the car and save the headache of disconnecting sensors and aging exhaust parts

[Edited on April 24, 2012 at 4:58 PM. Reason : ]

4/24/2012 4:57:27 PM

Nah man, it takes like an hour tops to pull that engine. Otherwise you have about 1 inch of clearance on the sides of the valve covers and you'll have old oil and coolant dripping out.

On a stand you can roll it over, do one side at a time and really keep things clean.

4/24/2012 5:03:40 PM

Quote :

"I like to coat those head gaskets with copper spray"

I do this for all headgaskets

4/24/2012 6:56:43 PM

sounds like a sticking t-stat to me.

4/24/2012 9:05:04 PM

it is head gaskets, and you will likely have to have the heads surfaced. it is %100 doable in the car, when we do them at the shop unless te engine needs a complete reseal it just stays in the car

4/24/2012 9:16:08 PM

Ah, good to know.

One more thing I remembered. You don't put Subaru's at top dead center on any cylinder to remove the timing belt. Instead you put all pistons in the middle. Makes sense, really; it completely eliminates the chance of valve damage. Belt alignment is done by painted marks on the belt.

4/24/2012 9:25:56 PM

Quote :

"I do this for all headgaskets"

because you are a nigger

4/24/2012 10:40:46 PM

Made a few discoveries. In the glove compartment there was a service receipt . . . . for the head gaskets, water pump, thermostat, and timing belt all being replaced at 120k. It has 165k on it now. The receipt also had machine shop labor for resurfacing the heads.

From what I can see of the gasket material protruding the shop used the correct updated multi-layer steel Subaru gaskets, which shouldn't have failed. Perhaps they didn't clean the old material from the block side properly, or torque the bolts in the correct sequence, or something else easily identifiable. If the weather co-operates I'll find out today.

4/25/2012 10:55:32 AM

Got the engine pulled. One of the lower engine to bell housing nuts was infuriating (you were right about that smc, definitely the hardest part), but finally found the exact combination of long(ish) 14mm socket and swivel head ratchet to get into the very oddly shaped space.




With the covers removed, the timing belt and water pump look almost perfect. And everything is all nicely marked, not bad. However:




Hmmm. The gasket is visibly more compacted on the top than on the bottom. I can actually see space between the layers of steel at the bottom edge. I'm thinking the shop might have cut some corners.


If weather permits today I'll pull the heads (the engine/stand are on my back porch now, covered with a tarp). I'm really curious to see exactly what was going on, if there's visible discoloration or channels where the exhaust could bleed into the coolant sleeve.

4/26/2012 2:15:43 AM

If it was not a subaru dealer or a subaru specific shop they tend to use shit parts. Mainly it they are not subaru head bolts, they can sometimes not clamp well. Same with the gaskets.

As long as you did not crack the block from an over heat.

4/26/2012 6:40:40 AM

Subaru uses Torx Plus head bolts, I think. You can use a regular Torx bit, if you're careful. I don't know if anyone local sells Torx Plus.



Unlike most cars, those cylinder heads have a separate cam carrier that has to be sealed. Once you dunk the head in the parts washer the old sealant will probably leak. Maybe I'm paranoid, but I always disassemble it and put fresh sealant. It's a silly design, in my opinion, but I guess it would be cheaper in the event of cam damage.



Anyway, the cam carrier needs to mate perfectly. I think I used Threebond 1194 on them since it reminded me of motorbike engine cases. You should double check that though.

[Edited on April 26, 2012 at 11:41 AM. Reason : .]

4/26/2012 11:28:18 AM

This probably goes without say, but if you disassemble the valvetrain, keep everything in the proper order, including noting which way the valve springs go.

None of this is necessary, of course, if you're just going to slap new head gaskets on it. But since the car has a history of overheating the heads will likely need to be pressure tested and resurfaced. This means they need to be stripped bare(the valve guides can stay). I'm sure some machine shops will do it with the valve train intact but I wouldn't recommend it...metal shavings everywhere. Anyway, you might as well lap the valves when you get it back and install new valve stem seals.

Check for obvious scratches and worn marks in the cylinder bores...but splitting the case is a whole other can of worms.

[Edited on April 26, 2012 at 12:32 PM. Reason : .]

4/26/2012 12:31:42 PM

I have done tons of Subaru heads and they are regular 12 point head bolts, either 12mm or 14mm head (I can't remember off the top of my head)

that splatter on the head is all from a broken CV boot.

4/26/2012 5:13:22 PM

^^ Had to disassemble the valvetrain to get to the head bolts. Have all the components nicely organized in a box.




Mark VII: Quite right, the splatter is from the CV boot which is indeed broken. And the bolts were 12pt.



So pulled the upper intake, which was so straightforward and easy I actually stopped and wondered if I was doing something wrong. Working on this engine as compared to the 302 in my old pickup is like night and day. Thanks Japan.

Lined up all the timing marks, pulled the belt, removed the valve covers and valve trains . . . . everything looks beautifully clean. Water pump and timing belt both look brand new.

And then I pulled the first head. It was immediately clear that the bolts had not been properly torqued, huge variance in force required to break them loose. Most "popped" twice as they were being loosened, some only once or not at all. Remove the first head and I'm greeted by this sight:



Yikes! Look like we've found our problem, and the diagnosis was dead on the money.





The areas where the exhaust was venting into the coolant sleeves are clear as day. Hot damn.




Other side is no different.


The carnage:





Dropping off the heads at the machine shop in the morning, new gaskets and bolts and other misc parts should arrive Sat. If all goes well it should be on the road this weekend!

[Edited on April 26, 2012 at 10:49 PM. Reason : Carnage]

4/26/2012 10:48:11 PM

if you aren't using some place nice like t-hoff, carquest in cary is actually really good

4/26/2012 11:15:47 PM

An amusing note . . . every cylinder had a different kind of spark plug in it. How the hell does that even happen? One Bosch platinum 4, one NGK, and two kinds of Champion (one of which was broken). Bizarre.

4/27/2012 3:45:25 AM

^ Probably because it's an absolute bitch to get to the spark plugs in the car.

If anyone has any insight on how to easily change these things, I'm all ears.

4/27/2012 5:37:14 AM

Yeah those do not look like the subaru gaskets.

hopefully the block is OK, I have seen quite a few that the overheating has taken a toll or somebody has put in cold water and cracked a cylinder sleeve.

it always amazes me that crappy shops always do this and do a timing belt, they replace th ewater pump, and I have honestly only ever seen one subaru water pump fail, so why replace? and they tend to re-use the tensioner which is never worth the risk.

What machine shop did you use?

What gaskets?

make sure when you put the headbolts back in lube the shit out of them, we will soak them in oil and make sure it is on the threads and the washers.

also don't re-use the valve cover gaskets, they have likely seen better days.

and remember clean clean clean! you can use easy off oven cleaner to get it spotless.

4/27/2012 8:21:30 AM

Actually they do appear to be the OEM updated Subaru MLS gaskets.




I'm assuming the issue arose from improper torque sequence on the head bolts rather than the gasket itself.

The machine shop I'm using is in Garner, my mechanic buddy uses them for everything and swears by their work. They're pressure testing the heads and going from there depending on what they find.

Gaskets and head bolts I'll be getting from Pep Boys, since that same friend has an account with them and gets a great discount. I had been planning to reuse the valve cover and other gaskets since they look perfect, but I guess I can just get the whole gasket set to be safe. Definitely figure I should replace the head bolts . . . at this point they've been reused twice and not torqued properly, so who knows what I'd be working with. The new gaskets will be Fel-Pro, and they're the proper updated multi-layer steel design (made in Japan, even).

4/27/2012 8:00:55 PM

I will say this DO NOT use any head bolt other than Subaru, unless they are ARPs,

I have seen nothing but trouble with the auto parts store bolts, and you do not want to know what it costs to have a block split to have a broken bolt removed deep in the block.

And sort of same with the gaskets, the fel-pro and or store brands fail, I am trying to speak from experience on this one, it is all Turbotime works on.

4/27/2012 8:13:51 PM

The issue arose because it's a Subaru. The fewer parts you use that have Subaru written on them, the better. This is a case where aftermarket parts can't possibly be any worse.

4/27/2012 9:15:59 PM

^ Not true, Subaru redesigned the head gaskets a few years later and eliminated the problem. In this case the issue arose because the shop that fixed it the first time did a poor job despite using the right parts.

4/27/2012 10:02:26 PM

FINALLY got it all back put together. Torque converter slid back when the engine was put in, it was a bitch to get it all lined up again and get the bolts in. Also took fucking forever to get the cooling system bled and all the air bubbles out, even parked on an incline.


But so far, so good! Ran it at 2k rpm for 20 minutes or so and it stayed at temp, then drove it a tad and it still seemed perfect. Tomorrow I'll take it on some longer test drives and then the highway.

5/21/2012 12:10:24 AM

Right on.

5/21/2012 12:36:25 PM

Looks like its good to go! Drove it for 3 hours or so around town and highway, put a few hundred miles on the odometer. Temp stays rock solid between 180 and 195 and the engine pulls and runs perfectly. Hell, even the AC works great which amazes me given how long it sat. Inspection passed and new plate on.

I'm calling this project a success. Only took me what, a month or so?



Now I can finally devote a bit of time to finishing up my motorcycle!

5/21/2012 9:54:57 PM