29 replies to this topic

[the3rsss]

99 outback 2.5 130k just replaced tbelt about 200r mi ago. Among other things, replaced waterpump and flushed cooling system. Recently, after a long hot trip with the ac on, I parked and smelled that sweet smell of coolant. It was overflowing from the resevoir. Went back down when it cooled. Nothing in oil. Coolant is fresh and looks it. Bottle is clean. No white smoke. Haven't reved it yet to look for bubbles or took a wiff of the bottle. What are common symptoms for this engine?

[the3rsss]

Ps... never overheated.

[nipper]

Well the symptoms are what you are seeing. Does it come and go? Did you have heat?

I would first go after the cheap things, thermostat and radiator cap.

Did the car actually get hot on the gauge?

It is possible there may be an air bubble, but it doesnt match up and you would have seen it earlier. It is possible.

A bad HG would show up on the temp gauge.

Did you replace the idlers and the seals also, or did you want more practice at chainging the timing belt

[samneric]

Ps... never overheated.

Guessing HGs.

Overheating will only occur after those symptoms.....

Have a test done on water to confirm.

Doing the same on my 98 OBW at the mo.

GL

Steve

[the3rsss]

Well, I'm very anal about my work. New thermostat and cap. Would pulling the heads and replacing the hg be a good idea for maintenance? If the failure rate is high I could do the job now and get a valve job while its apart.

[the3rsss]

Got engine hot and reved it. No bubbles in bottle. No exhaust smell either. Years ago they had dye you put in your water to test for exhaust in water. Guy in napa looked at me like i was crazy when I asked for it. Any other way , short of pulling the heads, to test? Compression prob won't help. Leak down test prob won't tell me anything. Pressurized cooling system? Any ideas?

[GeneralDisorder]

The coolant overflowing from the expansion bottle can only be one of two things - either the head gasket is beginning to go, or the radiator cap has a bad seal.

You can pressure test the radiator cap or just buy a new one. If this continues after you replace it - your head gaskets are leaking. Period. End of discussion. I've done a LOT of these 96 to 99 2.5's and also a couple 2.2's.... they always fail in the same way and that is the classic symptom. Exhaust gasses displace the coolant in the bottle - at some point the water pump cavitates and the temp spikes. It only gets worse - first you can drive 50 or 75 miles, then 10 or 20, then it does it within 5 to 10 minutes of startup.

You can do them premtively. Couple things you should know before you tackle this to make sure you are ready:

1. Pull the engine. You will not appreciate doing them in the car and the job can't be done to my levels of cleanliness easily without pulling the engine. Most other's here agree.

2. Use ONLY Subaru gaskets obtained from a dealership. The gasket design has changed 4 times due to premature failure. Don't risk your labor over two $35 parts.

3. Be prepared for sticker shock on a valve job for these heads. The DOHC heads are basically racing heads. They are VERY expensive to work on. Typically it's $450 to $500 to rebuild/reshim a set.

GD

Edited by GeneralDisorder, 09 July 2011 - 09:11 PM.

[eppoh]

There is a kit you can rent at Autozone, that tests the coolant for combustion gases.

It is easy and cheap ( free)

There is a little bulb sucker with a resevoir that you put a little chemical in. Then you position it on top of the radiator with the cap removed and suck a little air from the radiator into the tester. The chemical in the tester will turn a color if there is combustion gases present.

I used on on my OB before I bought it.

[GeneralDisorder]

I have personally seen cases where the head gaskets WERE blown and for whatever reason the HC test strips, etc failed to indicate it.

Take it from someone that's seen this more times than I can count - if it's not the radiator cap - you DO need head gaskets.

GD

[nipper]

Subaru Headgasket are litttle devils. They can pass hydrocarbon tests and the bubble tests when they start to go bad. replace the cap no money loss there really.

They are not consistant untill they get furthrer along.

[the3rsss]

Well.unfortunately your right. It is a cheap cap. Hopefully its junk. I'll get a good cap and see what happens. If I do need hg, do you guys usually redeck the heads? Anything else i should take care of while the engine is out?

[the3rsss]

Haha I'm thinking a valve job will cost me 50 bucks. Living in the past!

[nipper]

Haha I'm thinking a valve job will cost me 50 bucks. Living in the past!

:-p

You have to have them check for flatness AND the surface finish, otherwise may just give us the money then do it again., it will save work.

[the3rsss]

How does this sound..I can get a fel pro head gasket set for 75.00. Ill toss out the fel pro h gaskets and go to the dealer and get oem head gaskets, but use fel pro everywhere else. Dont want to do this job twice so any comments tips will be appreciated.

[nipper]

For the valve cover (plug) bucket seals they have to be OE also. Aftermarket do not seal properly and will leak quickly.

One word of advice. As soon as you drain the cooling system and remove the hoses flush out the radiator very well. Anitfreeze plus residual god-knows-what (there will be things from the HG leak you can not see) plus ari make a really good goo that is very good at clogging radiators.

[GeneralDisorder]

The Fel-Pro stuff is crap for Subaru's. Great stuff for my SBC.... worthless on a Subaru.

There really aren't a lot of gaskets anyway - intake, exhaust, HG, valve cover.... everything else is a seal, an o-ring, or RTV.

Get all your gaskets through the dealer. Seals and o-rings you can go aftermarket if you choose. But the big 4 that I mentioned above are never a qualit product if you don't buy them from Subaru.

GD

[the3rsss]

Ok. All subaru gaskets. How about bolts? Do you guys routinely replace head bolts? I'm ordering parts now. Anything else I need?

[phxmotorelectri]

Head gaskets for sure.

It takes awhile to totally go but you asre seeing the 1st stage. It will get worse within a week or so.
People like to remove the engine for this repair but I never do. Its tricky to remove the heads on the dohc 2.5 but totally doable w/o removing the engine. When the heads are out you willfind a couple exh valves too tight. It's important to address this.
I've had to replace exhaust shims to get a couple exh valves back to spec each time but i've never had to rebuild a head.

Just a simple head gasket job and valve adjustment and it will be ready to go.

The darned dohc head is indeed harder to work on that the sohc but I've yet to remove an engine to do this job.

Getting the valve adjusted is a pain because no one except hard core subaru owners have an assortment of shims. Bring the too thick shim with you to the dealer and get a couple thinner ones of different thicknesses. It's the only logical way to do it if you are doing the job yourself.

It's the head gasket but don't worry, it's normal. The 1st symptom is abrupt overheating AFTER a long drive AFTER you slow down, stop and then start driving again, even if you havent shut off the engine. Bubbles from the radiator (not the overflow tank) come and go in the 1st stages of hg failure of the dohc. It only leaks up under load at 1st but very soon the bubbles appear all the time.

200k mi is very good, VERY good, hg's normally fail on dohc engines at 150-170. I've yet to see one myself that made it to 200. 170 is the normal failure point for the one's I've worked on.

I†'s a pretty simple job; shave the heads, readjust the exh valves that need it (check the intakes too just to be sure) and it will be fine. If you do it yourself be careful to lay out all the shim bickets carefully where they will not be overturned by kids laying or dogs running around.

Q: why do so many people think removing the engine is needed for this job? It's not all that hard to get the heads in and out with the engine in place. I suppose if I was a shop I'd insist that removing the engine is needed, but since i just do it as a hobby for friends and neighbors, I keep it simple. And i have yet to have a problem doing it this way.

Why make the job such an undertaking? It does not have to be costly or complicated. It can be done for less than $200 if you do it yourself. It's not the end of the world and it won't last any longer doing it in place without a full valve job. I've done almost a hundred Subaru hg jobs and probably 25 dohc jobs.They are still doing fine, passing the strick California smog, and running right. It's just a part of owning a Subaru. I've only had to replace a valve once... it was when an exh valve went unadjusted for 160k. It did pit the mating surface a bit. But it certailnly wasn't "burned". Lapping it would have brought it back to life but just for fun I replaced the offending valves.

You caught it in the early stage. It will be fine. It's not rocket science and its not brain surgery. It's a car already and it's made to do this repair quickly and simply.

[the3rsss]

I guess you could pull the heads on the car but damn it looks tight! And what about cleanliness? I put together motors when I was young, all Chevy small blocks, and i know that cleanliness is half the battle! Just don't know how, with that engine design, I can get the surfaces clean enough. Id rather put extra work into it and do it right. Please let me know if I'm wrong. Trying to gather as much info as I csn.

[GeneralDisorder]

You are absolutely correct - cleanliness is why I and many others will ONLY do them with the engine out. It adds about 1 to 2 hours to the job total but results in a much better job. I pull the engine, steam clean it, drain all fluids, and reassemble on a proper engine stand. Then I steam clean the engine bay, reseal the oil seperator plate on the back of the engine, and install with everything clean and shiny and ready to go. It's not a matter of making more money - the engine pull itself is very easy and will actually SAVE labor in difficult dissasembly, reassembly, and cleaning. Plus with the vertical block surfaces it is very difficult to properly clean them or prevent coolant, etc from running out of the block while doing the reassembly. There's very good reasons for why those of us that do this all the time do it the way we do.

Head bolts do not need to be replaced. They are not a torque-to-yeild design.

Burned exhaust valves can and do happen when the valve lash is not adjusted properly. I've seen 1/4" holes burned in them with zero compression on that cylinder. I've seen it at 169k and on a solid-lifter 2.2 at 199k. The DOHC heads like to eat up their guides as well.... Typically I have the valves ground, the head resurfaced and new stem seals installed. Runs about $500 for the DOHC heads and about $175 for the SOHC heads. I do a lot of engine work and I've not had a single failure with my system.

GD

Edited by GeneralDisorder, 10 July 2011 - 07:50 PM.

[phxmotorelectri]

For all of us who have owned one or 2 dohc 2.5's we can all attest:
the h-g's will go anywhere from 120 to 170. 170 is the max i have seen and I've had two that went to exactlly 170 and then had strange seemingly atylical symptoms. But sure enuff...
Yes it's the head gaskets.
Bubbles will appear soon enough. You are ssing the 1st stage of failure where it only leaks while under load at high sppeds. It then overheats and dischsrges out the overflow tank after slowing down after a long hiway speed drive.
I drove allthe way from Cincinnati to Ann Arbor only to have it overflow and overheat after stopping to get gas. The next day i tried the same experiment after only a 15 mi drive and BOOM... it did the same thing.
Yes... do the head gaskets but NO you dont have to do a whole valve job.
The dohc engine is soooo nice in some ways but doing a h-g job is muchmuch harder than on any other Subaru engine.
Removing the cams... and carefully setting the cam buckets away is the key... also the real b..ch is that one or two (maybe more) of the valves (usually but not always its ehx valves) will need a thinner shil to get them adjusted right.
Do this w/o removing the engine is doable... I always do it this way... but many insist that removing the engine makes it easier... it is easier but how many people have a hoist of their own?
Don't worry! EVERY dohc 2.5 does this... ALL of them... I just shave the heads... adjust the valves (get an assortment of slightly thinner shims 1st), and put it back together.
I've never done a complete valve job on any of them and they are all running well with over 200k.
Hve fun... do it once and you'll never have to do it again.
We all have had to do this.
NO... you dont have to remove the intake manifold... just remove the I-M bolts and the head will drop out the bottom. It's an easier job than it looks like at 1st. BUT MACHINE the heads for sure!
Good engine! Rotten & complicated H-G job compared to all Subaru sohc h-g jobs. Have fun...

[grossgary]

good points about the valve adjusts and tight exhaust valves. they do ocassionally burn up so they should be adjusted, they're just super annoying to do.

For all of us who have owned one or 2 dohc 2.5's we can all attest:
the h-g's will go anywhere from 120 to 170.

there's no accurate mileage for them to blow, but there are some reasons it might *seem* like it. many were blowing at 30k, 50k, replaced under warranty by subaru, etc and some will last the life of the vehicle. of all the ones i've bought (a lot, i don't even know how many) - the earliest headgasket replacement was 33,000 replaced under warranty by Subaru on a 1998 Legacy GT. so you're estimates are about 100,000 miles off on the low side and about the same on the high side too. but we can also ascertain why it might appear as you say, it is actually quite reasonable to see and think that. it may seem that the mileage is meaningful but there are reasons for that:

1) there are few low mileage units around, but they were blowing far earlier than 100k when there were a lot of them still on the road with that few mileage.

2) the mileage you state is a good mileage to sell and be on the market for repair/sale. higher miles often ends up in the junk yard, lower mileages may still be worth repairing to many owners without getting voiced in forums or for sale.

EJ25D's are roughly 13 years old - at the national average of 12,000 miles per year - they're right smack in the middle of the range you mentioned - so a high percentage of them are going to be in the mileage range you specified. that doesn't mean they all fail - that just means most of them are 12-15 years old right now and likely to hit the market/repair bench with this mileage.

so - the numbers you suggest do come from somewhere - but they aren't actually indicative of "when" EJ25D headgaskets fail - they have no mileage preferences and some do make it the life of the car.

[Caboobaroo]

We actually sell complete gasket sets for doing headgaskets on these and they're an updated MLS headgasket. The brand is the Subaru aftermarket called 6-star and you've gotta be on a special program to get them. We do them all the time at my shop but we also sell all the parts, instructions, and some of the materials needed to do the headgasket jobs. PM me for details if you'd like!

[the3rsss]

Just an update. Got intake off, everything disconnected and unbolted. Engine is ready to come out.. went with all subaru gaskets. Not a bad job at all. Only real problem were the exhaust bolts. Soaked them, cleaned them, then heated them and still broke two off. Couple of questions...... why does the book say to mark the flexplate? What is the purpose of removing the dogbone? Why set the crank at t.d.c.? Finally, I want the heads cleaned, tested, new cam and stem seals, and surfaced. And oh yeah, a couple of helicoils. What would you guys consider a fair price?

[samneric]

Just an update. Got intake off, everything disconnected and unbolted. Engine is ready to come out.. went with all subaru gaskets. Not a bad job at all. Only real problem were the exhaust bolts. Soaked them, cleaned them, then heated them and still broke two off. Couple of questions...... why does the book say to mark the flexplate? What is the purpose of removing the dogbone? Why set the crank at t.d.c.? Finally, I want the heads cleaned, tested, new cam and stem seals, and surfaced. And oh yeah, a couple of helicoils. What would you guys consider a fair price?

Crank at tdc? isn't that so the pistons are positioned away from the valves so you can take the cams off without worry of valve interference?

Steve