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DIY 2001 Subaru Cylinder Head Gasket Replacement

144100 Views 116 Replies 27 Participants Last post by  greengoblin68
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.
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BTW, you might want to check this out: - /subaru_manual_scans/2000+_Legacy_FSM/

Not sure if it helps, but worth a look :)
absolutely go to josh's site and down load the 2000 FSM. you will be glad you did.

i don't recommend doing it in the car. i just did my first ''head gasket'' job and it was tedious on an engine stand. i cant imagine doing it in the car on a 2.5L engine. single or double cam does not matter. my .02 worth.

use ''subaru'' head gaskets, period. others may work fine, but you can get them online, both for about 75$ total plus shipping. others are not going to be dramatically cheaper. i use subau plug wires, and seals /gaskets for the cam, crank, oil pump o-ring (reseal it), and maybe the coolant crossover pipe o-rings, depending on the miles. everything else i use generic stuff from the parts store.

on my 01 HG job i spent $140 with a lacal dealer, wholesale (same as the online dealer cost) in subaru parts. i then spent about $250 for a timing belt kit (new belt and everything it touches, water pump, all idlers, and tensioner) on ebay, i use ''theimportexperts''. fluids and manifold gaskets, and NGK plugs i got from the local parts chain store.

also my opinion, if the engine has not over heated, you probably do not need to have the heads re-surfaced. (use the reverse torquing sequence to remove the heads) i did not send mine to the machine shop and mine runs great. i have heard that the some dealers don't even do it. if he engine runs good now, and you remove the head and re-install the head properly, it will run good when you are done.

FORGET top dead center. subaru almost NEVER uses it. they have adjusted all of the instructions for timing belt / head gasket work to be done with the pistons at mid stroke. use the FSM, or ask here, and set the crank to the timing alignment mark before you remove the belt. IT"S EASY.

use the hash marks , NEVER use the arrows. notice that the crank keyway is located down in the 6 o'clock position.

DO NOT remove the cam shafts. you do need to remove the cam sprockets to replace the seals, but not the shafts.

i would use a braker bar on the crank bolt BEFORE you pull the engine. put the trans in 1st and the hand brake on and have a friend stand on the brake pedal. or use the ''starter bump'' method. i have used a chain wrench and it works, but you run the risk of destroying the harmonic balancer. (your best bet is to use an impact wrench after you have pulled the engine, but they cost ~$50 at harbor freight). on reinstall, put the trans in gear and the hand brake on. (auto trans have a different procedure.)

TORQUE the crank bolt on re-assembly to 135 ft lbs. failure to do so and it will work loose over time causing trouble $$$.

no need to replace the head bolts. some folks insist that you must, but no where in the FSM does it say to replace them. be sure to coat the head bolt threads and washers with fresh motor oil at install. follow the torquing procedure very closely. you will need a torque wrench that goes down to 11 ft lbs.

good luck and stay in touch.
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subaru does not sell any head gaskets any more for the ej25 that are not MLS.
. 1)I thought TDC was an essential component of almost all engine repairs. It seems so dodgy to just ignore it. "set the crank to the timing alignment mark before you remove the belt." What is the timing alignment mark? How do I make sure I have correct timing when I put the belt back on?
as i understand it, TDC for most engines is crucial for setting the timing on an engine. for 2 reasons, 1> it is the only way you KNOW everything is lined up right. and 2> there are no other timing marks.

but subaru has given you timing marks. (do some research and reading.) if you align the crank and both cams (or all four cams depending) to the correct timing alignment marks the timing will be right.

it is alittle bit like paint by numbers. you can't really tell how it is going to look untill you are done, but if you follow the directions it will be right.

subaru has taken the thinking out of it.

the timing alignment marks are ''hash'' marks located on the front outer edge of the cam sprockets and the rear most edge on a ''tab'' of the crank sprocket.

to make it simple for you , assuming your timing is correct and the timing belt is still on the engine, if you rotate the crank sprocket until the notch in the crank sprocket for the key that keeps it set on the crank is pointing down in the 6 o'clock position, the timing alignment marks on the cams will either be lined up or 180 degrees off. if off by 180, rotate the crank one full turn, then all will be right. do this BEFORE you remove the belt. (you will not be able to see the key way in the crank sprocket until you have removed the front crank pulley.)


> timing belt pictures

good luck.
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yes, start at the top middle and then go bottom middle.

the next bolt isn't critical left or right, as long as it is a top corner.
then diagonal corner.

then back to the top same end, then the last , diagonal corner.
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