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Project: Rebuilding EJ25 with blown HGs


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A few months ago the EJ25 in my 97 Legacy OBW blew the HGs. I bought a used engine and put the blown one in my trunk. Now it's sitting in the basement and I finally have time to begin taking it apart.

 

Goal: Remove the heads, send them out for machining and order new OE HGs (4 layer, indestructible ones).

 

Question 1: How do I remove the heads? I understand I remove the valve cover and then remove the rocker arms. Are the head bolts right under the rocker arms?

 

Question 2: Does anyone know of a good machine shop in the New Haven, CT area?

 

Question 3: Is there a suggested source for the OE HGs, or will any OE online dealer do?

 

Question 4: Anything else I should consider doing while I am "in there"? Replace the pistons?

 

I plan to put on a new rear main seal, PCV plate, valve cover gaskets, cam seals, oil pan gasket. When I reassemble the engine I'll also put on a new water pump and timing belt.

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There are no rockers on the DOHC - just the cams. When you remove the cams the bolts will be accesible. 6 of them.

 

It's best to have an engine stand so you can put the engine at a 45* angle to the floor - that way the buckets and shims won't fall out while you are loosening the head bolts. After you remove the head, reinstall the cams but don't torque the cam bearings or anything - the machine shop will need the cams and bucket/shims to do the valve adjustment when they grind your valves - they will have to take material off the stems. As a side benefit though the machine shop should be able to reuse most of your shims which will save you $6 each on those.

 

If it had any piston slap you could replace the pistons with the coated one's that Subaru provided to cure the problem for customers that were annoyed by it and complained. But in the interest of saving money it's really not neccesary as piston slap is not a serious problem.

 

If the rear main is not leaking - don't touch it. They typically only fail after someone replaces one. They are silicone and typically last the life of the engine.

 

DO replace the oil seperator plate and bolts. Likely it will already be leaking anyway as you will have the plastic one.

 

Cam/crank seals for sure. Cam seals will come out when you pull the cams anyway and you should pull the oil pump, reseal it (loctite 518) and replace it's o-ring.

 

Water pump, timing belt and all components of course....

 

As for online dealers - here's the two I've used:

 

www.subarupartsforyou.com

www.1stsubaruparts.com

 

Both are dealerships so both will sell the 4 layer gaskets - it's the only gasket availible for your engine according to the parts listings so you don't have to worry about not getting the right one.

 

GD

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GD,

 

Fantastic reply! Thanks!

 

Alright, so I have to remove the cams. I take is they are held on by a bold or nut and will slide right off when removed? Maybe I'll spray them down with a little liquid wrench.

 

No rocker arms. Good to know!

 

How many head bolts are there total? Should I get new bolts when reinstalling or reuse the old ones? Also, please suggest a cam seals.

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Check on the Subaru OE gaskets. I'll make an order of those. I'll get the head, crank and cam seals.

 

Here's the next question- what should I do with the block? It's got 220k miles on it, but wasn't burning oil or knocking before the HGs blew. Should I begin to tear it down?

 

I'm going into the basement now to take the cams off.

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the block is a tough question. great engines and 220,000 miles doesn't scare me. but they do loose enough bearings and throw enough rods that dumping a ton of money into one is questionable. if you're sure it wasn't overheated much then i'd roll with it. i'm guessing the frequent overheats due to headgasket issues may contribute to the lower engine issues. i'd roll with new headgaskets if you know a bit of it's history.

 

i picked up a 56,000 mile legacy GT earlier this year with a locked up bearings in the block. head gaskets were replaced at 34,000 miles. purely anecdotal of course but i think others have said it before too.

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I am in the basement and have a 17mm socket on the bolt holding one of the four cam sprockets on. However when I try to turn the bolt the cam rotates with it. How do I remove the bolt without turning the cam?

Edited by bstone
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You have two options - use an impact or remove the valve cover and there are some flat spots on the cam where you can put a wrench. Personally I just use an impact.

 

GD

 

Valve cover is off. No impact here- this is a basement job with hand tools. I'll try to stick a wrench into the valve flat spot. Wish me luck.

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Right side head is off! I wasn't prepared for how easily the head would come off, but I caught it. The head gasket came right off, as well. Below is a picture of each side. Sorry if the quality sucks, I used the camera on my laptop. How do they look?

 

Photo on 2010-10-17 at 22.24 #2

 

One of the piston walls has a line of burn on it about a half inch wide and going down. The other is smooth to the touch and feel.

 

I am pooped now and tomorrow will do the left side.

Edited by bstone
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Can't really tell much from that quality of photo. The tiny details are what matter when you are talking about blown head gaskets - The key is to look for a spot in the fire ring where there is carbon tracking or it otherwise looks different from the "normal" look they have after being removed.

 

This cylinder wall damage is interesting - I would lilke a more detailed photo of that if you can get one. This is more concerning than where the gasket blew out because it's unusual and the gasket blow-out is common and expected with the flawed original gaskets anyway.

 

GD

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I am looking for the camera, but it seems to be missing.

 

I agree that the burn on the cylinder wall is interesting. Pictures when I can find the camera. Tomorrow I'll take off the left side cylinder head.

 

I didn't see any shims. When I bring the heads to the machine shop should I bring the entire head? Anything else?

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Under each cam lobe is a shim - it sits on the bucket - which is like an inverted shot-glass that sits directly atop the valve stem. This is known as the "Bucket and Shim" system. It's specific to the DOHC type engines typically. Other manufacturers use it as well - Subaru is not unique in their use of bucket/shim for DOHC designs. Some makers have gone to hydraulic buckets without the shim while Subaru (in 2003?) went to "shimless buckets" where the shim is now part of the bucket and when you do a valve adjustment you replace the entire bucket......

 

Clear as mud? :rolleyes:

 

And yes - if you so choose you in fact could convert to shimless buckets at this time. Though the cost is about $300 at the dealer parts counter......

 

GD

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While at the junkyard getting an IAC Solenoid Valve I got a referral to a machine shop in the area. Stopped in and they said they would do each cylinder head for $50. $100 total for the heads. Not bad.

 

Sadly, they don't do engine blocks, so I need to find a different place for that.

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that sounds about right for resurfacing cylinder heads. place i go to in WV does them for $15 each to resurface, but they don't warranty them without a pressure test which costs more. doesn't charge a minimum shop fee like they do in MD. WV isn't a stellar economy so it's far from the norm.

 

that shop should be familiar with someone to do the block and crank work.

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