Subaru Outback Forums banner

DIY 2001 Subaru Cylinder Head Gasket Replacement

149K views 116 replies 27 participants last post by  greengoblin68 
#1 ·
Hi everyone,
Yes, I'm new to posting on this forum, but trust me, I have poured over the threads and used this site on several occasions to fix my 2001 Subaru Outback, standard transmission, 2.5L SOHC 4 cylinder engine. Finally, at over 160K, my subie has developed the famous external head gasket leak. Yes, drivers side, rear. I have oil weeping from the seam, coolant in the back. Yes, I have strange odor. The coolant in my reservoir is still green but seems to be leaking more than the oil in my engine (which is not milky). I know what I need to do, the question is whether or not I can do it myself. I'm strongly inclined to try, but this would be the biggest automotive repair project I've ever tried. I've been studying these forums and reading and rereading my Haynes guide. My Haynes is going to be the step-by-step for my actions, specifically Chapter 2, Section 12 (Cylinder heads - removal and installation). Most of the instructions on this refer you to other manual sections, which I've spent the last two weekends just reading, looking and planning, and I think now is a good time to ask a couple of questions.

1) TDC vs. camshaft sprockets. Haynes instructs me to find Top Dead Center of the #1 cylinder by adjusting the camshaft pulley with a breaker bar while a compression gauge is in the sparkplug hole. I have a pretty good idea where this is already (the marks are still on the pulley from an earlier timing belt change), but I will run through the procedure anyways. I'm not really sure what to look for on the compression gauge though. Are there any play-by-plays out there for what to do exactly? Next I take off my drivebelts, then after a few other removals, Haynes recommends using a chain wrench to hold the pulley while loosening the crankshaft pulley bolt. I'm not sure about using a chain wrench here. Does anyone have any comments or alternatives? I feel like I'm going to have to wrench the heck out of the crankshaft pulley bolt. Correct me if I'm wrong, but if I get even ONE tick off of TDC I'm screwed here correct? Last question on this point, and I feel like I have a big knowledge gap here, but after removing the pulley and the covers and the timing belt guide, the next step is to "Turn the crankshaft and align the marks on the crankshaft sprocket, the left camshaft sprocket and the right camshaft sprocket with etc., " Won't this throw off my TDC? I'm hugely concerned about this, if you respond to nothing else, please advise on this.

2) Camshaft removal - after removing sprockets, valve covers, CMP, rocker arm assembly, tb tensioner/bracket, and dipstick Haynes says to remove the "camshaft end cap assembly" then "remove the camshaft carefully from the cylinder head so that the lobes do not nick the journal bores. Remove the camshaft oil seal and the end plug from the camshaft end cap assembly." Is this it? There are no diagrams, no photos. I'm just really vague on what to expect when I get in there, what it will look like.

3) Unforeseen difficulties - I'm planning on being methodical. In fact, I will be photographing EVERYTHING, labeling EVERYTHING with tags and I writing EVERYTHING down. When I'm done, it will be posted. Promise. I'm planning on having to buy some tools. Of course I'll need a torque wrench, spark plug remover, compressor gauge, chain wrench, and pin wrench. I have a wrench set, socket set, hammer (just kidding). I also plan on replacing the left/right valve cover gaskets, spark plugs and, of course, cylinder gaskets. I guess I'll need new cam seals too. I have some money for unforeseen expenses, I have a little time, a place to work. Is there anything else that I'll need that you can think of? Has anyone who has followed the Haynes (or Chilton. . .it's about the same) done this before and found out that something just wasn't covered properly? I want to get everything I need, then do this all at once. I want to keep this car running a while longer, I also want to learn about what is under my hood. Thanks for all your help.
 
See less See more
#94 ·
Well, I've got the L side head out, still need to remove the R side. I did it w/o removing the engine, took off the intake manifold. I did loosen the three motor mounts and raised the engine maybe 2" to gain better access. I left the radiator in, but removed the fans - there was more than enough clearance. The car is an automatic, and I didn't want to deal with transmission fluid from the cooler lines. In a manual, I think I would have just yanked the radiator.

Really burns me that I had to duplicate 3 hours of work, having done the timing belt and cooling system last month. I only had the car for a limited amount of time and it was a chance to do some exploratory on it. Unfortunately, one of the findings of that exploratory, was the oil leaking externally from the L head gasket. Removing the intake was no picnic, but the electrical wasn't too bad. I've done this on a 3 series BMW and undoing the electrical connections has been the downfall of many. The EGR fasteners were a challenge - the upper one was easy, as I removed the EGR valve for cleaning. The lower one really calls for a stubby 22mm open end; I use an 8 in. adjustable. I may buy a 22mm crowfoot for reassembly.

So now that I've got the head off, should I tear it apart, replace the valve stem seals and camshaft seals? It's really filthy, full of greasy oil and grit; I hate to just slap it back on that way. And there is a bit of dirt inside the head from the removal process. I don't plan on doing any machine work on it. I'm a bit anxious about removing the camshaft bearing and having to reseal it - currently, it doesn't seem to be leaking, and I'd rather not create a leak where there wasn't any.
 
#95 ·
I thought about the automatic cooling lines after I posted. Mine is a manual. Duh.

I don't know your backstory...need to go back and read it. These engines usually leak oil through the piston rings and most people leave the valves alone so I just had my heads ground flat at the machine shop and left a pair of new camshaft seals with them to install because it isn't unheard of for these seals to develop camshaft seal leaks at high mileage and it costs next to nothing to have a shop install them with a grind. At 214k with 40k on Subaru reman shortblock and turbo headgaskets I am burning a quart about 3k or so...way less than it ever did except maybe when it was brand new before it blew the headgaskets the first time but probably more than some people would want. I am tickled.

Sent from my SM-G900R4 using Tapatalk
 
#97 ·
Both heads are off now. I hadn't planned on tearing them down, but I think that was naive; I can't see how to clean up the gasket surface and remove all the ensuing crud from the cooling and oil passages without at least removing the rocker arms and camshafts. I may get away with leaving the valves and springs in, although I'm leaning towards replacing the stem seals. I did order a Torx Plus IP40 bit for the camshaft cap.

What are people using for a spring compressor on these?
 
#98 ·
heads:
if these are really cruddy and worn EJ251/EJ252 heads at 200,000 miles, where you are there you might find replacements in better shape cheap and easy.
(pick and pull, ...craigslist part out, any colorado corner lemonade stand). If they are later 2003-2004 type with the EGR hole, just get or make a cover for it.
edit: and make sure the engine airbox looks like the one you are working on, 2004 EJ259 weirdo caliifornia spec ones could be poking around.

and hand machine or pay a machine shop to resurface what you are going to use:

DIY Head Resurfacing... or "Post-apocalyptic machine shop techniques!" - Old Gen.: 80's GL/DL/XT/Loyales... - Ultimate Subaru Message Board

that link to USMB, was used in this thread, which you might like to look at backwards
http://www.subaruoutback.org/forums...ngine-swap-us-jdm-ej251-diy-head-gaskets.html

@idosubaru do you have any advice for this nice fellow,...
(doing the head gaskets on a 2001 era 2.5, that have been done before by others,...but sprung a new oil leak now, and he is doing it outside in Northern Colorado...)

_____


Edit: I was thinking suspension here:
spring compressors from what I see on here and locally: people rent/ borrow stuff from the local parts store, using 2 on one assembly, sometimes with large plumbers pipe band clamps if they need another 1"
 
#99 ·
It's leaked twice (at least - that we know of) already at the headgaskets:

1. I'd want to resurface the block and heads need resurfaced because something isn't right.
or
2. prior job used inferior gaskets

You're kind of guessing what's going on here, which makes it tough...don't want to do too much or the wrong thing or miss something or waste time/money - might be best to just go with route #1 and be done with it. Call around for shops that can resurface blocks or try it yourself like the link above. get good abrasive materials and lubricate well so it doesn't just rip the abrasive paper.

I wouldn't touch the valve stem seals without compelling reasons - NA engine don't typically have many issues with them. but I can understand wanting to do them while you have a it apart, I have too.

the spring compressors i've used suck on SOHC Phase EJ25 engines, I hope you find better ones. i have two compressors that can't do them effectively due to clearance issues - it's a circus. i ran all thread through a socket, cut a notch in the side of the socket to extract the valve keepers, and then bolted a cam sprocket i had lying around to the other side of the allthread - its' about 2 feet long. I wedge the sprocket on my shoulder and just push/lean into it while i extract the keepers. you can also use PCV pipe which is easier to use for people without metal cutting equipment or sacrificial sockets. WAY faster than the spring compressors which take FOREVER to set and work for each valve - wash rinse repeat 16 times. but pressing 16 of them in by hand isn't for everyone either, some people aren't going to be able to do it.

if you want a compressor I would just find out what the subaru specialists are doing and just buy one and resell it when you're done. that's what i'd do but i so rarely want to go this route i don't need one. if i needed valve work i'd just do what EE said:

buy a set of used heads.
 
#100 ·
It's leaked twice (at least - that we know of) already at the headgaskets:

1. I'd want to resurface the block and heads need resurfaced because something isn't right.
or
2. prior job used inferior gaskets

You're kind of guessing what's going on here, which makes it tough...don't want to do too much or the wrong thing or miss something or waste time/money - might be best to just go with route #1 and be done with it. Call around for shops that can resurface blocks or try it yourself like the link above. get good abrasive materials and lubricate well so it doesn't just rip the abrasive paper.

.
@paulsomlo is doing this with the short block in the car,

outside, trying to "get 'er done" before it gets too cold,.

...not ideal but just doing it inexpensively for a girlfriend as they repaved the parking lot where she lives, and she has a leaker.

and from what you typed I wonder if the short block face is nice and wrinkled when warm.


@traildogck do you know of nice big cheap pick and pull parts yards north of where you are? in case he's looking for heads. ..or even a long block
(he's close to WY).
 
#102 ·
How long have recent girlfriends lasted lol:

Less than a year - install cheap eBay gaskets
1-3 years - install Subaru or Fel Pro gaskets
3+ years - install Subaru/FelPro and resurface heads

Local shops should charge less than $100 to resurface the heads. You don't need a valve job pressure test or warranty so just deny all that.
 
#103 ·
Thank you all for the replies and links, very much appreciated.

The situation is, this a woman friend's car (not the girlfriend). She bought the car in late Spring, paid $3,000, and has put another $1200 into it since. We're trying to contain costs at this point, since she may only keep it a year or two. So, things like swapping heads, engines etc., are probably not in the cards.

My plan is to resurface the heads using abrasive paper and a granite surface plate. If the block is warped, I'm kind of SOL - I'll probably just have to live with it, because I don't know that I'm prepared to pull the engine, and I don't know that she'll want to spend the money to have the machine work done. Once I get the block cleaned up, I can take a straight edge to it and see where it's at. The head gaskets I ordered are the Felpro MLS. Weather is not really the constraint here - the owner is away on vacation until Sept. 18, so I've got the car until then. Even so, it doesn't really get prohibitively cold here until November.

As far as cleaning the heads - can I get away with just removing the cams and rockers, leaving the valves and springs in? I can turn an adapter on the lathe for compressing the valve springs, in conjunction with a woodworking clamp. I have one that I made for use with my 318ti, but it's too large to clear the spark plug tubes. I was thinking about something like this: https://www.amazon.com/Lisle-36050-Keeper-Remover-Installer/dp/B0012S61IO, which, being pretty much cylindrical, would make for an easy lathe project.

I'm curious - is there some risk involved in replacing the valve stem seals? You said you wouldn't touch them, and the Subaru service manual that someone had posted online has a similar warning.

By the way - I keep seeing these engine codes being bandied about; EJ250, EJ251, etc.. How do I know what I'm working with? And is there a guide online that explains the differences?

Oh, someone mentioned mileage earlier - the car is around 198,000 mi..
 
#104 ·
By the way - I keep seeing these engine codes being bandied about; EJ250, EJ251, etc.. How do I know what I'm working with? And is there a guide online that explains the differences?

Oh, someone mentioned mileage earlier - the car is around 198,000 mi..
in US / Canadian spec years for the EJ25 N/A of 2000-2004:

EJ251 automatic 2000-2002
EJ252 manual trans 2000-2002

then the merged they just started to call them both EJ251 in 2003 and 2004.

same engine, just with the different trans: different pulleys, one MAP one MAF, and 2003-2004 have EGR.

_____
 
#105 ·
Cleaning the block is proving to be a challenge. The heads are on the bench, so I'm able to work carefully with a razor blade. And any slight scratches will come out on the granite surface plate/abrasive paper. But the block, being in the engine bay, is another story. I'm down to the last of the gasket material, maybe 0.002" thick at the most, and it's really tenacious. It's difficult to work down in there carefully with a razor blade, and I haven't found any chemicals that will soften this stuff. I've tried the permatex gasket remover with the brush, isopropyl alcohol, acetone, engine degreaser, and Citristrip. The Citristrip softens the deposits on top of the piston, but doesn't seem to do much with the last of the gasket residue. I'd rather not use anything abrasive, like Rolocs, etc.. Is there a miracle in a can that I'm missing?
 
#107 ·
I have used cheap tire and wheel cleaner to remove crud from red lock-tite,

but that was on a threaded drain pipe that I soaked in it overnight, and then scrubbed with a metal brush.
 
#108 ·
I've hit a snag - the cam cap bolts are stuck. The ones with the Torx Plus head, that is. The hex head ones were easy, but I can't move the others. I've tried Kroil, acetone/atf, hand impact wrench, Milwaukee M12 cordless impact, wacking the fastener head w/hammer to jar it. I tried a propane torch on the casting where the bolt threads into, but I didn't get it much beyond warm and am afraid to get the casting too hot. I may try "freezing" the bolt head. Anything I may have missed? If I can't get those Torx Plus fasteners out, I'll have to clean up the surface with the granite surface plate/abrasive paper, then try to flush out the head with the cams in. I worry about getting the oil galley clean of all the debris from scraping the head while the bottom was facing up.
 
#109 ·
Success! I heated the aluminum casting again where the threaded bosses were, then heated the bolt heads, although I wasn't able to get them very hot. I think what helped more, was taking a punch to the inside of the fastener head and giving it a dozen or so wacks with a ball peen hammer. And I don't think I was really leaning on them enough to start with - they're 8mm fasteners, so the danger of snapping one is minimal. I have a cordless impact that's good for 800 ftlbs; in retrospect, that's what I should have used.

So now that I've got the cams out, is it standard practice to remove the valves to clean and surface the casting? I may or may not replace the valve stem seals.
 
#110 ·
#111 ·
thanks eagleeye - after reading the link, I decided to go ahead and remove the valves and replace the stem seals. I took the heads to the car wash and gave them a good dousing. I notice that there are hex plugs at both the front and back of the head, as well as two inside the head - are all four of these plugging the oil galley? And if so, would it be a good idea to remove them to facilitate cleaning?
 
#112 ·
Just wanted to update all of you: I finished up and returned the car to it's owner several weeks ago. I did take apart each head, replacing the valve stem seals and giving each valve a quick lap. To remove the valve keepers, I used a socket with two 3/16" dia. magnets shoved up inside the socket, diametrically opposed to each other. In conjunction with a woodworking clamp, they made removing the keepers very easy. Getting the keepers back on, was not so easy though. I used a piece of tubing with a cutout, and a woodworking clamp and it took about forever - incredibly frustrating. The right tool would have paid for itself quickly in terms of frustration avoided.

In retrospect, I wish I had pulled the engine. I was only two hoses and whatever the bell housing bolt count is, away from having it out. Removing the heads with the engine in is not difficult, since you're not worrying about munching the old gasket. Getting it back in took many tries on each side, as the bolts have to extend from the head and you're always worrying about the new gasket getting dinged, not to mention the dowel pins on the block scratching the newly resurfaced head. And carefully cleaning the block in the engine bay is misery - constantly bending over, poor access, etc.. It's worth removing the block to be able to have access to clean it properly and not worry about scratching it because you can't get a good angle with the razor blade. I did finally find a chemical that would attack the gasket residue - Aluminum Jelly (Loctite), the aluminum version of Naval Jelly. I guess the phosphoric acid does the job.

By the way, those four hex plugs on the head all lead to the coolant chambers.

I'll attach a picture of the surface of the head - I started with 320 grit, finished up with 400, using a cheap 9x12 granite surface plate from Woodcraft.

The car doesn't run any better now, but the oil leak is gone. Hopefully, she makes it through the winter trouble free. I've already told her that she needs to be thinking about a new car.
 

Attachments

This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top