Overheating, what makes a Subaru a Subaru! But hopefully it's just the radiator cap

[slacktide_bitog]

1998 Forester EJ25D

Temperature gauge went all the way to the H. Coolant spilling out the overflow bottle, upper radiator hose hot but collapsed, radiator cap cold! The coolant poured out of the overflow bottle and didn't seem to vent out from the cap. The fans do turn on, so the thermostat is probably fine. There is no weep like you'd get from a dying water pump.

I ordered a Sankei radiator cap from Napa that will be ready to pick up today.

Hopefully that's all it needs and not a new head gasket

 

[Rand]

oof early 2.5 good luck on the no head gasket needed hopefully not a dream.

 

[CarLuver]

from your description i would be surprised if its not the head gasket. if the car is still solid i would fix it

 

[mk378]

Check head gasket before buying anything.

 

[MRC01]

+1 to the bad news about head gaskets. Overheating increases the chance of them needing replacement. As you replenish the coolant, Subaru has a conditioner you can add. If the head gaskets are bad, the conditioner won't fix them, but it can't hurt and might postpone the inevitable.

 

[The Critic]

from your description i would be surprised if its not the head gasket. if the car is still solid i would fix it

Yeah, I don't think a radiator cap is going to fix this.

 

[Rand]

2.2L was a solid engine the 2.5's esp early ones (like yours) were NOTORIOUSLY bad for headgaskets. but if the car is solid the 1.5k is worth it?
In the most common failure mode the combustion gases pressurize the radiator and blow it out into overflow.

That and the fact that it did overheat... well best of wishes. Its worth it to find an independent subaru specialist because they wont cut as many corners doing the job.
many will use roloc type tools etc and it wont last long. The heads may need machined flat too.

 

[The Critic]

Its worth it to find an independent subaru specialist because they wont cut as many corners doing the job.
many will use roloc type tools etc and it wont last long.

Like this guy?

 

[Slow Car Sport Mode]

1998 Forester EJ25D

Temperature gauge went all the way to the H. Coolant spilling out the overflow bottle, upper radiator hose hot but collapsed, radiator cap cold! The coolant poured out of the overflow bottle and didn't seem to vent out from the cap. The fans do turn on, so the thermostat is probably fine. There is no weep like you'd get from a dying water pump.

I ordered a Sankei radiator cap from Napa that will be ready to pick up today.

Hopefully that's all it needs and not a new head gasket

If it is a head gasket issue, replace it with an EJ255/257 metal one. Not sure if that will work on an EJ25D.

They are the turbo gaskets. Change everything and do it right and it should be a permanent repair.

If this will even work on an EJ25D.

Yes, start with the cap in diagnosing your issue.

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[Slow Car Sport Mode]

from your description i would be surprised if its not the head gasket. if the car is still solid i would fix it

Take radiator cap off when engine is cold, like sitting overnight or when you know it is cold. Open hood. Turn engine on with the cap off.

Coolant should not shoot out. It should stay level.

If it shoots out, cancel the order on the cap and schedule a proper head gasket repair.

 

[MRC01]

Take radiator cap off when engine is cold, like sitting overnight or when you know it is cold. Open hood. Turn engine on with the cap off.
Coolant should not shoot out. It should stay level.
If it shoots out, cancel the order on the cap and schedule a proper head gasket repair.

Emphasis on proper. Most of the cost is labor and if you're going to do all that work you might as well do it right, which means machining the heads to ensure they're flat -- especially since it has overheated. And checking a few other things too, like valve guides. And of course timing belt, tensioner, pulleys, water pump.

 

[Trav]

I have a bad feeling about this one, this could get real expensive real quick. If it overheated there is a good chance a rod knock could be right around the corner if it isn't already.
The cases may need to be decked as well as the heads planed. then comes the question while it is all apart what other work should be done eg valve job, guides, rings, bearings, line bore the cases, etc.

There is no half stepping when repairing this engine even properly cleaning the case decks and planing the heads using a MLS gasket may not be enough to prevent premature failure of the new HG.
When they overheat the cases expand too much around the crank which allows the crank to get tight, it also twist the cases causing to main bearing bores to go out of alignment.

The cost of machine work is very high today, when I do these for other people I use a brand new Subaru OE short block and have the heads done with 6 stars MLS viton coated HG, absolutly no copper coat.

Another cause for HG failure is broken ground straps from the heads to the frame, I replace them with 1.5" braided plated copper straps as well as adding addition grounds.

 

[Slow Car Sport Mode]

Emphasis on proper. Most of the cost is labor and if you're going to do all that work you might as well do it right, which means machining the heads to ensure they're flat -- especially since it has overheated. And checking a few other things too, like valve guides. And of course timing belt, tensioner, pulleys, water pump.

I always take note when a shop talks about doing it right. Some shops simply understand Subaru.

Some don't want to touch them.

It has been said almost everything on a Subaru is an engine-out repair anyways, because a 2.5 is so low wide and flat.. not sure if that is true, apparently there is some socket and extension magic that can get spark plugs out (I dont see it. Seems shoved in there to me, a la AMG C55 and C63) but. My shop, says, when I want my Turbo gaskets put on, it will be three days and they send the heads out to be machined on the lowest setting, to accommodate the thickness of the new gasket.. maybe an extra step, but I have heard other Subaru people do this.

The picture shown, I think I see grinding wheel marks.

 

[MRC01]

... Another cause for HG failure is broken ground straps from the heads to the frame, I replace them with 1.5" braided plated copper straps as well as adding addition grounds.

Nice tip - thanks!
PS: on these older cars, the cost for this job can quickly add up to more than the vehicle is worth.

 

[Slow Car Sport Mode]

Nice tip - thanks!
PS: on these older cars, the cost for this job can quickly add up to more than the vehicle is worth.

That's why, if you get it done, you drive the car into the ground, lol.

Ground strap, make sure connecting surfaces are clean bare metal.

 

[slacktide_bitog]

shopping for head gasket sealers now

ChrisFix did a nice video on the Bar's Leak with carbon fiber


I'm considering that one as well as the cheaper K-Seal sealer mentioned in the video

 

[Trav]

shopping for head gasket sealers now

ChrisFix did a nice video on the Bar's Leak with carbon fiber


I'm considering that one as well as the cheaper K-Seal sealer mentioned in the video

Some of those may work for a time but with these open deck all alloy block engines you there isn't much hope.
HG failure is why so many otherwise perfectly good EJ25 scoobies are scrapped.

 

[Slow Car Sport Mode]

I've been down the HG sealer road.

Really depends 100% on *how* it is blown...

Usually, the sealers will seal the leak and the engine will run okay if left to idle, or driven very, very lightly. Do any kind of real driving with it and it will blow again in a week, a month, a day...

YMMV but. Having spent hundreds of dollars on sealers.. I still ultimately ended up getting a new (new-to-me used, a new engine is $3600. I checked) engine.

I am still probably flushing sealer out of my heater core, honestly.

 

[GSCJR]

Another cause for HG failure is broken ground straps from the heads to the frame, I replace them with 1.5" braided plated copper straps as well as adding addition grounds.

I had no idea! Ironically, that's one of the first things I did to my newly acquired Legacy. Seeing those broken grounds drove me insane!

 

[Slow Car Sport Mode]

I had no idea! Ironically, that's one of the first things I did to my newly acquired Legacy. Seeing those broken grounds drove me insane!

I'd like to see these straps, I *think* mine has (we've changed everything on it but the trans. And even parts of the trans. Runs perfect) been changed but I'd like to verify.