mystery coolant leak on 2005 2.5 NA Subaru

It's kept pressure for like half an hour and there's no coolant in the oil. A local shop couldn't find the leak (did they not try hard? They also didn't try to sell me a new alternator though it's grinding bad) but I got my UV light in today and found coolant coming from somewhere above the power steering rack. What on that motor is immediately above the power steering rack that would leak just a little coolant? PO (JShaawbaru) said he'd notice the level decrease after like 150 miles

2005 Saabaru 9-2x 2.5 NA

My two craziest coolant leaks were a pinhole leak in the line to the expansion tank on our '17 Odyssey and a bad radiator cap on my E36 that was misting coolant under pressure (finally saw what was happening at night). I'd look for the highest spot highlighted by the UV dye (or the strongest concentration).

Aren't Subaru 2.5's notorious for external head gasket coolant leaks? 

rattfink81 said:

Aren't Subaru 2.5's notorious for external head gasket coolant leaks? 

mine pushed oil out from there, not coolant. Those gaskets are notorious in general though. 

Apexcarver said:

rattfink81 said:

Aren't Subaru 2.5's notorious for external head gasket coolant leaks? 

mine pushed oil out from there, not coolant. Those gaskets are notorious in general though. 

If you let it go long enough it will develop an external coolant leak along with the oil. At least that was my understanding with the 2.5 foresters. 

Is any coolant leak on a Subaru really a mystery?

My aunt's 2006 Forester needed head gaskets this year at 55,000 miles. I had taken it in for an oil change and couldn't believe it developed the issue at such low mileage. I guess that's what makes a Subaru, a Subaru.

Logically, it's a Subaru, therefore head gasket.

QED

Yep you guys called it. I finally put 2 and 2 together and realized that it has a flat engine (the first I've ever dealt with) and that I was staring at the union of the head and block as the highest point of leakage. Poop.

PO said he ran it like this for 1,000 miles so I'm not throwing it away just yet, but I'm not sure how much $$$ I want to throw at the car in the meantime. It will be $900 and a long weekend for a replacement engine with 150k on it, but as others have said, it appears to be a matter of "when" not "if" I'd have to do that yet again.

Your rally is on public roads.  Sign up for AAA's big package that will tow the car home 100 miles or the bigger package that will tow 200 miles.  Roughly $100 or $150 respectively.  Bring extra premix coolant.   

Don't wait to buy the AAA, there may be a 3 day wait from buying to using for towing.   I am making the assumption that you are not trailering the car to the event but rather driving it there and back.   

Don't throw away that motor because the headgaskets are gone, it's pretty easy to do them on these as you don't need to disassemble the heads to get them off. These motors are very easy to pull, all of the transmission bolts can be removed from under the hood, the power steering and AC can just be set aside and the intake comes off as one unit with all the fuel rails and everything attached. The only thing you need to get at from underneath is to drain the oil, coolant, unbolt the two motor mounts and the exhaust manifolds (which is easy on these as the bolts are directly accessible rather than buried on the side of a head against the firewall in a normal car). Once it's out just pull apart the timing belt setup (now's the perfect time to replace all of that including idlers and water pump) and pop the heads off. I even DIY the head resurface rather than pay a machine shop, it's really easy with a piece of thick glass and some 400 grit sandpaper  glued on. While it is out throw some spark plugs in it, replace the valve cover gaskets and do a quick valve adjustment, slap it back in and enjoy it for another 100,000 miles. USE A FEL-PRO MULTILAYER HEADGASKET OR A SUBARU TURBO HEADGASKET!!! That will save you doing this job again.

First time I did this I had it done over a 3 day weekend, it's all very straightforward. 

I do a figure 8 motion on the sandpaper unlike his back and forth in the video as I feel it gives a more uniform finish. I'm actually doing a BMW 6 cylinder head right now using the top of my Grandma's old glass coffee table lol

Some pics from the last time I did this, also on an EJ253 like yours. The glass I used here cost under $40 from a local glass place, I think it is 3/8" thick.

Before:

During:

End Result, nice and flat:

And yes, refinishing heads using a piece of glass is about as Grassroots Motorsports as you can get in my opinion.

adam525i (Forum Supporter) said:

Don't throw away that motor because the headgaskets are gone, it's pretty easy to do them on these as you don't need to disassemble the heads to get them off. These motors are very easy to pull, all of the transmission bolts can be removed from under the hood, the power steering and AC can just be set aside and the intake comes off as one unit with all the fuel rails and everything attached. The only thing you need to get at from underneath is to drain the oil, coolant, unbolt the two motor mounts and the exhaust manifolds (which is easy on these as the bolts are directly accessible rather than buried on the side of a head against the firewall in a normal car). Once it's out just pull apart the timing belt setup (now's the perfect time to replace all of that including idlers and water pump) and pop the heads off. I even DIY the head resurface rather than pay a machine shop, it's really easy with a piece of thick glass and some 400 grit sandpaper  glued on. While it is out throw some spark plugs in it, replace the valve cover gaskets and do a quick valve adjustment, slap it back in and enjoy it for another 100,000 miles. USE A FEL-PRO MULTILAYER HEADGASKET OR A SUBARU TURBO HEADGASKET!!! That will save you doing this job again.

First time I did this I had it done over a 3 day weekend, it's all very straightforward. 

 

I do a figure 8 motion on the sandpaper unlike his back and forth in the video as I feel it gives a more uniform finish. I'm actually doing a BMW 6 cylinder head right now using the top of my Grandma's old glass coffee table lol

I 2nd this. A few years back, I went with a buddy to buy a NA/Auto Forester that was priced so low it seemed too good to be true. Turned out it was, because it overheated on the drive home. Needed a HG. We felt kind of defeated, but another buddy convinced us that the HG job was super easy. He was right. The job was so easy that you can screw it up and redo it multiple times in the collective span of a few hours. Our experience went like this:

-Ordered some head bolts and recommended "Six Star" gaskets

-Had the motor go from installed and running to hanging from a cherry picker in 45 minutes

-Installed the gaskets and had the motor back in the car a couple hours later

-On the first start up, oil shot sky high from between the head and block on the driver side

-We realized the gaskets weren't as symmetrical as they looked and we had put them in backwards (alcohol may or may not have been a factor as well)

-Needing the car on the road ASAP, we scrounged up two over the counter gaskets from chain auto parts stores, all of which seemed to only stock one

-Had the motor out again in record time and swapped in the auto parts store gaskets

-This time the gaskets went in correctly, but the car still ran kind of funny. Still putzed around OK for its intended use, albeit now without the overheating.

-Symptoms ended up pointing to a toasted valve. Got a good used head on eBay (maybe $150-200?) and a 5th gasket

-Figured out which head it was and swapped it the next weekend without pulling the motor this time. Ran great after this.

We used subpar gaskets and I don't exactly remember doing any real extensive re-surfacing, but despite this it ran around just fine for quite some time before it either got totaled or caught fire or both, I can't remember.

TLDR - I'd at least try to replace the gasket(s) before dropping the coin on another engine since it's a pretty easy job.

OKAY! Now we're talking! My hope has been restored!!

thanks, guys!

As down as I am on Subarus in general, I agree that a low-mileage engine that is in otherwise good condition shouldn't be tossed.  There are videos on Youtube showing head gasket replacements in the vehicle. 

Time for an adventure!

My experience with Subarus is that they always leak coolant. You can replace and replace and replace parts and they will just find a new place to leak from. Head gaskets, water pumps (I had one of those that only leaked once it was shut off) , coolant crossover pipes on top of the engine, radiators, hose connections. Same with engine oil as well. They are the leakingest damned things.

Sometimes Subaru coolant leaks can be kind of sneaky. I had a 2002 WRX a few years back that was losing coolant toward the end of winter. It didn't leave anything on the ground, and even with UV in the coolant and the light there weren't any obvious external leaks. I was pretty much convinced it was a HG and figured I'd top off the coolant (with that expensive stuff from the dealer) and baby it until Spring when I could dive into a HG job. 

Right after Spring came around the leak started to get worse and revealed itself. Turned out the T-stat housing outlet was corroding from being caked with salty road grime and coolant was seeping through the hose connection. I'm guessing when the leak was smaller it must've been dripping down to or spraying the exhaust manifold where the coolant would evaporate before it could be detected. I cleaned up the t-stat housing and replaced the hose and clamp and no longer had any issues.

Out of curiosity, what does a proper HG replacement cost on a NA 2.5 from a respectable shop?

ProDarwin said:

Out of curiosity, what does a proper HG replacement cost on a NA 2.5 from a respectable shop?

Prolly between $1500 and $2500.

I've done over 60 head gasket replacements on EJ25 Subaru's starting about 15 years ago.   I pull them without taking the motor out, but that's just me. 

My local machine shop rebuilds the heads and does a valve job/valve stem seals/resurface/pressure test.  They've caught a few cracks and more than a few bad valve's over the years (remember kids, the valve lash is adjustable).  Cost is about $175 for the set so it's not worth my time to DIY.  They come back looking like brand new.