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09 Legacy GT, 08 Legacy 2.5i, 09 Outback 2.5i
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Discussion Starter #1
My son's 09 Outback 2.5i appears to have blown a head gasket on his way home from auto tech college this afternoon. He said it started running really rough and so he decided to pull it into our workshop and just as pulled in it stopped and he thinks it hydrolocked since it would not turn over. Drivers side head gasket was spewing coolant from the top and he said it appeared to be very hot - although he had not looked at the temp gauge. Oil on dipstick is full and clean no contamination that I can tell. Timing belt looks perfect and was changed ~3 months back. We have it torn down now to the point where the intake manifold is off and I have a few questions.

1) What is the procedure to remove the camshaft sprocket bolt?
2) Will the valve cover and head come off without jacking the engine off the mounts and moving from side to side? Son says no way and I recollect not needing to when I did heads on my dad's 96 Legacy.
3) With the intake off there is a wide open service opening for the trans torque converter bolts. Seems like they should have had a rubber plug for this but I don't know. This car @ 212k miles has had both the engine and trans replaced with used units by who knows who service shop. Maybe the plug was overlooked...

I did check and it will turn over fairly easily now with a breaker bar on the crankshaft bolt so I am hoping that mechanically it is alright and just needs a head gasket and machining, etc.
 

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1) I have a tool for holding the sprocket. The curb side, you can fairly easily jam a screwdriver in the spokes if it's not too tight. The roadside has the plastic cover making that more difficult. I have used a screw driver against the bolts that hold the plastic cover. This works if the bolt is not over tightened. You should be able to remove the head without removing the sprocket.
2) The kid is right... 2008 has VVL. The VVL hardware under the valve cover makes it more difficult to get them off. You will stuggle a bit even loosening the mounts and shifting the engine side to side.
3) About half of the Subaru's I work on are missing that plug. It breaks easily and usually isn't replaced. It's probably a good idea to have it in place, but I don't think it is critical.

* I would recommend pulling the engine out... they come out really easy and the head gaskets are a huge pain to do with the engine in.

There is some pretty detailed discussion with varying opinions on what the best practices are for this job in the head gasket section of the maintenance section. I would encourage you to read through them.

Good luck with your project!
 

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2008 OB Limited 2.5i, Portland OR USA
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.....just as pulled in it stopped and he thinks it hydrolocked since it would not turn over.
Did he actually attempt to crank it? If so, that can have consequences to the bottom end if it really was hydrolocked.

However, I can't imagine a cylinder filling up with coolant that fast.

Note from the description given the leak appears to be external, so the fact that you later turned it over by hand with a breaker bar and noted it moves freely doesn't mean it wasn't hydrolocked when he first pulled it in.

Drivers side head gasket was spewing coolant from the top and he said it appeared to be very hot - although he had not looked at the temp gauge.
Overheating can have consequences to the heads - check them for flatness when you have them off.
 

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Discussion Starter #4
He said he had tried to crank it after it had died in the shop and it would not turn over. He does not know if the starter engaged or not so unknown what the cause might be at this point. Can it seize from overheating and then be alright again once cooled down?
 

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He said he had tried to crank it after it had died in the shop and it would not turn over. He does not know if the starter engaged or not so unknown what the cause might be at this point. Can it seize from overheating and then be alright again once cooled down?
If it actually seized due to an overheat there is damage that it won't recover from. If it hydro locked from a stop, it is probably ok, but there is a small chance that it could bend a connecting rod.
 

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Discussion Starter #6
I am doubting the hydrolocked line of thinking on this. That would take a lot of coolant leaking into the cylinder and the external vs cylinder bore seals on the head gasket are separate. We have the drivers side head off now. Looks definitely like a head gasket leak at the top middle. I am unsure of his description of how/why it would not start. Is there a good way to judge the condition by looking at the cylinder bore with the heads off?
 

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I would look the cylinder walls over for signs of scuffing. If the bores look good, I'd say chances are good that it will be fine.
 

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Discussion Starter #8
Both heads off and it looks good in the cylinders. Original honing crosshair marks are very clear. I am thinking to machine the heads, new fel-pro head gaskets and put it back together and hope it starts...
 

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Fel Pro and Six Star are also good along with the 2.5i Turbo H4.

Just don't use the stock 2.5i NA H4 single layer gasket; that was the problem in the first place.
 

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1999 30th Anniversary Legacy Outback DOHC 2.5L 4EAT, 2008 Impreza WRX 2.5L 5MT, 2008 Impreza Wagon 2.5L 4EAT
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Will this work on a NA 2.5i engine? I had been reading that the Fel-Pro gaskets were the best choice.
Use what you want. People smarter than me and that have done 100's of head gasket jobs use the Turbo gasket on the NA 2.5 engines. I even used it on my EJ20.
 

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I use Fel-Pro MLS gaskets and have good luck with them. I'm sure turbo gaskets work well also. I suspect you will be fine using either.

If you choose to machine the heads, be sure your machine shop is capable of machining to the finish required for MLS gaskets.
 

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Discussion Starter #15
My son did a great job helping getting the heads off yesterday before he had to go to work in an April blizzard in MN. Anyways, the heads are off and the cylinder bores look fine no scuffing that I can discern. I'll ask my son if he wants the turbo or Fel-Pro gaskets. What is the detail re the head finishing for the Fel-Pro MLS gaskets?
 

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Discussion Starter #16
Oh, and to answer one of my first questions re this job... The valve covers will come off with the engine in place but there is not enough clearance to remove the heads without jacking the engine up a few inches. Must remove the exhaust manifold, the two engine mount bolts, the rear center support, and then jack the engine up to get the heads out.
 

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Machine surface finish is measured in RA (Roughness Average). Here is what Fel-Pro says regarding their product:

"Select PermaTorque MLS gaskets feature a special coating formulated specifically for the aftermarket repair environment. While most MLS gaskets require a surface smoother than 40 Ra (240 Rz), these Fel-Pro® PermaTorque MLS head gaskets will seal a surface finish as rough as 60 Ra (360 Rz). Regardless of the brand of MLS gasket chosen, for the gasket to seal properly the finish on the head and block must be flatter and smoother than what has traditionally been required for composite gaskets. It is important that technicians consult their machine shop for specific surface finish capabilities."

You also want to be careful about how you clean the block. Don't use any kind of a power tool or aggressive sanding. That will damage the surface finish and affect the ability of the gaskets to seal. I use scotch-brite and brake-clean to hand scrub the surface.

Because of concerns about proper finish and the machine shop's ability to reproduce the factory finish, I usually don't surface the heads unless there are defects in the sealing area or the head has warpage beyond Subaru's specifications. If you are interested in going that route, the process for determining if the head surface need machined is covered in the Subaru service information.
 

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Discussion Starter #18
Heads appear to be in spec for flatness so we will clean them up and put together with new Fel-Pro gaskets. Are new head bolts really required or just recommended?
 

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Fel-Pro "requires" that they are changed, so I always change them. There is a ton of debate about on this board over whether or not they should be changed.....

 

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Discussion Starter #20
New Fel-Pro MLS gaskets and head studs are on the way. The heads are not awesome for flatness but I am going to cross fingers and put it back together and hope it works...And tell my son to seek a job so he can purchase whatever car he desires.

Does anyone know the part number for the shoulder bolt that is for the valve cover. This 09 OB was missing one and my son took another one off this to replace a broken one on our 08 Legacy 2.5i at school today. So, need two of them. There seem to be a plethora of them online but all with different dimensions. Subaru website does not appear to show the bolts.
 
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