Critique My EJ253 HG/TB Repair Plan!

[carfreak85]

It’s kind of crazy to think how long I’ve been in the Subaru game and yet I’ve never replaced a 2.5 head gasket!  I only want to deal with this repair once, hence this thread:

I was under my wife’s 1999 Forester for an oil change over the weekend and noticed the bottom of the driver’s side of the engine was COVERED with engine oil.  I had long suspected that it was the cam seal leaking, but the volume of oil and the area it covered has been slowly growing over the last few oil changes.  A little research revealed that the EJ253 in this Forester likes to pop its head gasket and then leaks oil externally, which correlates with what I’m seeing.  We lose about 1-2 quarts of oil between changes (I top it up often) but the engine doesn’t appear to burn any oil (no smoke out the tailpipe, hot or cold).

The head gaskets were originally replaced at 78k miles (w/ P/N 11044AA633 head gaskets) and the engine now has about 205k miles on it now.  We’re past due for a timing belt as well, so here is the list of parts that we’ve got so far:

Timing Belt Parts:

• Timing belt

• Tensioner/idlers

• Crank pulley bolt

• Water pump & gasket

• Thermostat & gasket

• Cam seals

• F/R Crank seals

• A/C idler pulley

• Oil pump reseal/O-ring kit

   

  I’ve been doing a bunch of research on what else I should touch “while I’m in there.”  In past posts @GeneralDisorder has suggested changing out the piston rings, installing knurled pistons and upgrading to a 10 mm oil pump.  I will have the heads milled (if still in spec) but what else should I consider?  Valvetrain work?  Is there anything I can do to help oil drain back to keep the pistons from getting clogged? 

   

  Head Gasket Parts:

• 770 head gaskets

• Exhaust manifold gaskets

• Intake manifold gaskets

• Valve cover gaskets

• Valve seals (int. & exh.)  (I’ve read that the SOHC engines have a tendency to drop exhaust valve guides and that these should be knurled to keep them from dropping?)

• Sparkplug tube seals

• Valve cover bolt grommets

 

Misc. Parts:

• Spark plugs

• Spark plug wires

• 10mm oil pump

• PCV valve

• Knock Sensor (original is cracked)

• Battery cables/tie down/j-bolts (battery terminals/tie down are fuzzy and have read this is a potential cause of driver’s side gasket failures)

   

   

  So, flame suit on, please let me know what you think of my parts list!  Are there obvious omissions?  Are there parts I could swap in for little expense that will help power/longevity (such as uprated camshafts, pistons, etc.?)  Note, this isn’t a performance build, so I’m not thinking about forged, high-compression  pistons or anything, but if there is an OEM piston that I could swap in that would provide a slight performance advantage, I would be interested in something like that, or Delta Cams, etc.  How far away from a Frakenmotor would I be?  Would an STI oil pan be something to install?

   

Edited January 5, 2022 by carfreak85

[idosubaru]

make sure it is the headgaskets first.  other things will look like HG leaks. 

crank pulley bolts never fail, no need for that. 

make sure it has a metal rear separator plate and reseal that.  subaru says to add the subaru coolant conditioner, I believe GD says do the job right and don't use it. 

 

initially your 99 forester factory headgaskets normally leak coolant first - and it was covered under an extended 100,000 mile headgasket warranty by subaru and they'd add the coolant conditioner.  replacement gaskets have more varied failure modes - coolant, oil, internal leaks. 

[ThosL]

On my '97 2.5 I don't worry about an oil leak, as the valve cover gasket replacements involve a lot of hours and oil is relatively cheap and if I put in a quart every couple weeks the level stays safe.  That looks like an ambitious plan, I wonder how many hours you are estimating the work at and expense.

[GeneralDisorder]

99 should already have a 10mm oil pump I think..... definitely check. 

642 gaskets are a slightly better fit to the head cooling ports. Though it doesn't matter in the least. 

The valve guide dropping issue is on the 2006+ heads. The stem seals are viton and you need not touch them. I would lap the valves though. Or have a 3 angle done. 

STI oil pan and dipstick (different length) will increase capacity, has better baffles, and this way you don't have to clean the old one when you do rings. 

NPR rings, NO honing. Drill the carbon out of the drain back holes, knurl the skirts and hand file them to a net-zero fit. 

GD

 

[carfreak85]

9 hours ago, GeneralDisorder said:

NPR rings, NO honing. Drill the carbon out of the drain back holes, knurl the skirts and hand file them to a net-zero fit.

Do you folks offer this service and if yes, what is the cost?  I don't trust myself to do that correctly...

Are there any modifications/tweaks we could do to add, say, 20 hp without braking the bank?  (We load this car up and do a lot of mountain driving).

[GeneralDisorder]

Yes we can and do offer re-ring services for short blocks, etc. It's about 4 hours labor for removal and reinstallation / ring fitting, plus the knurling which is $25 per piston and includes putting them through the parts washer till all the carbon is dissolved. Rings are $50. So it would be $546 parts and labor. 

As for adding power - you can do a cam grind which will likely not make "more" power but will move the peak power around, or you can shoot for a compression increase which in the case of that engine which already has flat-top pistons, would mean milling the heads and using eccentric timing idlers and slotting the intake manifold bolt holes. Plus running exclusively high octane.

GD

[carfreak85]

So I got another chance to climb under the Forester yesterday.

The back of the flex plate and torque converter look dry.

The area around the cam seals/timing belt covers appear to be dry.

The passenger's side head is bone dry, except for a very minor weeping along the HG at the front end of the bottom of the head casting.

The driver's side looks to be leaking oil.  There is oil along the length of the HG on the bottom of the head, dripping down the exhaust flange and studs, flowing backwards and soaking the crossmember, skid plate and the elbow of the header, near the transmission.

The leak hasn't been leaving noticeable drips on our driveway, but when I removed the skid plate, there were some drops at the trailing edge that looked ready to drip.

 

So, should I just replace the timing belt and wait for the driver's side gasket to start leaking coolant externally before I replace the HG?

[idosubaru]

personal preference.  how much oil is it loosing now?  has the smoking off the exhaust started to annoy you?  will wafting smoke in traffic or drips on the driveway/garage bother you?

hard to say particularly with the HG already being replaced, those have less predictable prognosis in terms of how quickly they get worse or incur additional symptoms. 

i would consider just installing the belt and timing pulleys now. timing belts are pretty easy and quick so it's not like a crazy time savings or waste to do the belt and let the cards fall where they may regarding the HG.

if you plan on owning this car 100,000 more miles you'll be doing exactly one headgasket job no matter what, so the only savings you have are either that you're living month to month and don't have the funds now (but most people in that situation won't have it later either), or the "risk" of possibly loosing the car between now and the date you could have replaced the headgasket had you waited - in which case you wouldn't have needed to do it.

if you drive it 20,000 more miles and it averages 1 quart per 1,000 miles that's 20 quarts of oil and roughly the cost of one+ headgaskets. 

if you know you'll eventually replace them anyway and the smoking off the exhaust has started to become noticeable/slightly annoying, and time and money are no concern then maybe consider doing it now. 

 

 

[1 Lucky Texan]

future external coolant weeping might be cured with Subaru Coolant Conditioner.

Edited September 12, 2018 by 1 Lucky Texan

[GeneralDisorder]

Well obviously I'm biased because it's not much of a thing for us to do these, but I would swap them out with 642's and be done with it. 

But yeah if you don't mind it being nasty under there - essentially forever till the HG's are replaced - then drop in the coolant conditioner, and run it. Change out the engine mounts, and steering rack bushings for urethane so the oil soaking doesn't turn them to goo. Same with the rack boots but those you just have to change out regularly when they got swollen and fall off. 

GD

[carfreak85]

Well after some further inspections it looks like the HGs ARE leaking onto our driveway, which is not OK and requires the HG be replaced.

SO, does anyone have any tips or tricks of the trade while I'm in there?

I think we're going to skip the knurled pistons, due to time constraints (we have about a week to turn this around) and my lack of confidence to do it myself.

[forester2002s]

Take lots of photos before you disconnect anything.

As you remove nuts and bolts, put them into containers (old yogurt containers, cut-off plastic bottles, children's snack containers etc). And in each container put a small piece of paper, with a brief description, e.g. 'starter-motor bolts', 'valve-cover bolts' etc.

If your engine is dirty/oily, I suggest doing an engine shampoo before you start.

[carfreak85]

@GeneralDisorder Should we be replacing/resealing the oil pump?  Check the assembly bolts?  Do we need to change the oil pickup to use the STI oil pan?

[GeneralDisorder]

Yes you need to change the pickup to use the STI pan. 

The pump will say the size in the upper left hand corner on the outside. If it says 10 then just leave it be. If it's a 7 or a 9 then replace it with a 10.

We never see the backing plate bolts back out on these, and we don't bother with the o-ring. Reason being there are three more of the same o-rings between the engine block case halves and since those aren't being replaced either...... we never see a problem with any of these o-rings anyway. They invariably look fine if you pull off the pump or split the case, etc. 

GD

 

[carfreak85]

GD, when I looked up the oil pump part number for this chassis it was listed as a 10mm pump, but I will double check once the timing covers come off.

Sidenote, as we tear into the car to get the engine out I noticed this when I pulled the PCV assembly.  Not quite 100% blocked in any of the PCV hoses, but getting darn close!

My first impression is that there's not much I can do to avoid this besides running a synthetic oil, but what do the experts think of this?  @Gloyale@idosubaru @GeneralDisorder

Edited September 19, 2018 by carfreak85

[GeneralDisorder]

That is the poster child for synthetic oil, and regularly replacing the PCV valve and cleaning or replacing the PCV to block hoses/fittings. Don't neglect to remove the separator plate on the back of the engine and clean that also. 

With new rings, and synthetic oil, this will basically become a non issue going forward. 

The pump size marking is visible without dissasembly. It's right above the timing cover on the passenger top corner. 

GD

Edited September 19, 2018 by GeneralDisorder

[carfreak85]

So @GeneralDisorder at this point should we just spring for the updated pistons w/ new rings or ship my shortblock to you for knurling/re-ring, find a new shortblock and just toss that in?

[GeneralDisorder]

Well you can just put rings on the old pistons. They will seal fine you will just continue to have piston slap is all. 

There aren't really any "updated" pistons - just new pistons with new skirt coating, which eventually wears off and then it goes back to slapping. I suppose maybe they changed the barrel design of the skirts.... problem is that skirt to wall clearance is probably somewhat larger than it was when the block was new, and unless these factory style pistons have pretty darn tight skirt to wall, or are heavily coated with teflon, they slap like a forged piston no matter what you do. When we knurl them we put them back in with zero skirt to wall clearance and just let them run themselves in. Gives the engine a slightly diesel sound to it if you are standing in front with the hood up. Basically inaudible from the cabin. The pistons are sized A, B, and C, and in order to get the specific sizes, the only source is the dealer - if you buy aftermarket they are all one size and will slap worse than what you have now (without knurling). 

Another option is to go to forged pistons, and the JE's we have been using for the last few years on our turbo builds are surprisingly quiet. They have a skirt coating also. They are a 2618 alloy. We never knurl the forged pistons - we just let them do their thing. If they slap - it's almost considered a badge of honor. Means you have forged pistons. The kids love that. 

And yes if you wanted to ship it, we could handle that for your also. A replacement short block.... well if you wanted that option I would just get a reman from the dealer. About $2k and comes with a 3yr/36k warranty. 0 miles.....

GD

[carfreak85]

Getting mixed messages on cylinder head bolts.  Reuse, or replace due to TTY?

[GeneralDisorder]

They are NOT torque to yield bolts. Subaru has never used TTY head bolts and there is no mention of replacement in the FSM. Just clean them with mineral spirits, or a parts washer. Do not use a wire wheel or brush or anything abrasive - it will remove the anti-friction coating. If any have pitting damage or rust replace only those. Reuse the rest. Lube them with Amsoil assembly lube. Chase the block threads (an old head bolt with a couple slots cut up the threads works well), and run the bolts in and back out a couple times (head off) with the assembly lube to pre-lube the block threads and check for any binding. Reapply assembly lube to the bolt for final torque. If you feel any binding or tightness to the threads STOP and asses the situation. If you seize the bolt in the block and it breaks off you are totally F'd. 

Edited September 24, 2018 by GeneralDisorder

[idosubaru]

43 minutes ago, carfreak85 said:

Getting mixed messages on cylinder head bolts.  Reuse, or replace due to TTY?

Reuse. Subaru says it as do well versed Subaru people. 

Fel Pro and outliers blaze their own trail of replacement

take your pick.

You only need to know if you replace bolts or not. I wouldn’t think I’m terms such as “TTY”, in a sense it doesn’t matter and unnecessarily muddies up the water. 

[carfreak85]

My parts guy was trying to be helpful and auto-corrected my order to the 633 gaskets, thankfully the 642s were in stock and the same price!

I will inspect the bolts and reuse, if acceptable.

[carfreak85]

Does anyone have the End Wrench article or Subaru TIB/TSB that outlines the HG procedure?  Just want to make sure I'm not missing any steps...

@GeneralDisorder@idosubaru@Gloyale

Edited October 4, 2018 by carfreak85

[forester2002s]

This might be the EndWrench article that you refer to.

WhBearRep.pdf

[GeneralDisorder]

Unfortunately, the Subaru official methods leave much to be desired. They tell you what to do, for the most part, but leave out how, or their answer to the problem is simply "throw it away"...... better to just find your own way through it. Use common sense. What specific questions do you have? Clean the bolts with a degreaser - no abrasives or wire wheels. Chase the block threads and clean with brake or carb cleaner. Lube the bolts with Amsoil assembly lube. Make sure the small washer bolts go in the corners. If you get ANY creaking from the bolt, back it off and reassess the situation.