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DIY 2001 Subaru Cylinder Head Gasket Replacement

143929 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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Sprocket marks need to line up each revolution of the crank. The timing belt marks will not line up every revolution. Basically when I do the belt, I put everything back on, then the toothed sprocket by the water pump, then the top idler near the oil pump, then lastly the bottom smooth idler. Just push with the palm on the idler while using a socket to start the bolt by fingers so you can feel if it is started correctly. Put some bubble wrap or something under the car so if the idler gets away it doesn't get a burr on it.
Yup, I gotta problem. Got the belt on, everything lined up, put the rest of the engine together, filled up on coolant and started it up. . .it started, for about 10-15 seconds until I shut it back down because of the shrieking noise and smoke/steam coming up. . .I guess I'm screwed. It was late, so today I'm going to loosen up the drive belts a little bit, change the oil and pull it off the ramps. . .then Ill start it up, give it some gas and see what happens. . .I'm not optimistic. . .but if figure I have nothing to lose at tbhis point. . .
UPDATE:! Actually, things are looking up. I loosened up the belts and that solved the screeching (way too tight) and then I let it idle for around 20-30 minutes and no more smoke. I'm getting ready for a test drive. Fingers crossed!
:) yay, congrats you'll be fine
By the way how long it take you ?? I will be working flat on back in garage . I asked several mechanics and they said to pull motor if no lift
Test drive went well! I shifted through all gears, checked the AC, heater, cruise control. Things went well. Then I got home, pulled into the driveway and put it in neutral and the battery light popped on. Opened the hood, the alternator was spinning so I'm not sure what is wrong. Maybe the belt is TOO loose now? Or maybe a connection? Also noticed a little leakage on top of the power steering pump, not real bad though. But the important stuff, the gaskets, the smoke, the shrieking noise are not problems anymore. Gaskets look good everywhere, no leakage at all. So I shut it down and I'll tighten up the PSP clamp and check my connections again and then change the oil and tool around town this weekend before trying it out on the commute.

I'll also put together a post next week describing my process. I have around 150+ photos (HUGELY helpful when reassembling) and about ten pages of notes (also HUGELY helpful when reassembling). It took me about two weeks total, just a little short. Some long days on the weekends and nights after work. I did not need to pull the motor, I needed a little help at actually removing the heads but that's about it. Having the truck up on a set of ramps was important, you just need the clearance. After I break out the numbers I think I'll have saved about $600-1000+, acquired a set of nice Craftsman tools, and, most importantly, learned how my engine works. I can not emphasize enough that I AM NOT A MECHANIC. I didn't even do my own oil changes three months ago. If you take your time, be methodical, stay organized, study the manual, take photos, take notes, double check your work, follow directions and consult with others more knowledgeable than you (I called mechanics, parts shops and checked in with this forum regularly), you can do this work yourself. Many thanks to everyone who has offered timely advice, or has posted in the past, you were CRUCIAL to helping on this project. In the end, saving money, acquiring tools and knowledge (and did I mention I lost 7 pounds ?) are a great way to spend a couple of weeks. I hope others can learn from the dialogue that occurred here! Thanks!
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Also noticed a little leakage on top of the power steering pump, not real bad though.
You haven't by any chance tightened the belt cover down too much? Does the pump make noise, i.e., is there air in the fluid?
I actually had the belt cover OFF when I took it for a drive. Maybe that was the problem? I didn't hear any noise coming from the pump but the steering was a little jerky right when I turned the wheel the first time. After that no problems. I don't think the PSP is a big problem right now, I'm actually more worried about the alternator, but also, not a big problem given that yesterday I was worried about my MOTOR.
Sounds good! Hopefully your accessories are OK. I overtightened that belt too when I did my timing belt, and my PS pump started making noise, but it didn't go away even after loosening the I ended up replacing it. If yours leaked a little, some air may have gotten into the system, hence the jerky feeling you described. There is a purge procedure, something like front wheels off the ground, engine off, turn wheel lock to lock _slowly_ a few times.
Congrats on your HG replacement job. For having no prior experience, you did well. :)
Ralfanfwilliesdad FTW.
ralphandwilliesdad -

Any guess what the initial smoke/steam was from? I can understand a little smoke from oil residue around the exhaust headers after a few minutes, or something similar...but to have it within 10-15 seconds of startup would be very disturbing to me too! I'm glad it turned out to not be serious...
OK, i done made another mistake i should know better than. i noticed the blue paint on one end of valve springs when i was pulling em out but didn't think anything of it, just assumed that was the mfgr's color coding for spring static length or tension.

now i go to reinstall and notice that these are variable rate springs, where one end has much tighter coils than the other, presumably to avoid valve float at high rpm's. except Stupid here didn't note which end was up when they came out. can anyone help me out here? do the closer-spaced coils go towards the head or towards the retainer? Haynes is of course no help here....manual doesn't even discuss removal/installation of the valves.

OK, i done made another mistake i should know better than. i noticed the blue paint on one end of valve springs when i was pulling em out but didn't think anything of it, just assumed that was the mfgr's color coding for spring static length or tension.

now i go to reinstall and notice that these are variable rate springs, where one end has much tighter coils than the other, presumably to avoid valve float at high rpm's. except Stupid here didn't note which end was up when they came out. can anyone help me out here? do the closer-spaced coils go towards the head or towards the retainer? Haynes is of course no help here....manual doesn't even discuss removal/installation of the valves.

In the FSM (MSA5TCD00L16123.pdf), it says; "CAUTION: Be sure to install the valve springs with their close-coiled end facing the seat on the cylinder head."

That's for the 2000 Legacys. But don't sue me if it's not correct. I haven't done this myself, so you might want to wait for someone else to chime in.


OK, thanks! that's what i suspected, as the springs normally compress from the top down (ie, the tightly wound coils will be the last to compress), so i'm sure your info is still correct for MY2002 engines. just feel better having the confirmation.
Could someone please further explain how to prepare the engine block surface prior to installing head gaskets. Also explaining how to protect the cylinders from contamination.
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Just finished a HG replacement on my '02 outback 2.5L, following the sequence presented here:

My complements to the poster, it was right on the money. We encountered no significant difficulties, beyond a sticky crank pulley (FWIW, penetrating lube and wiggling by hand freed it, after gentle prying failed). Great to have this info available on the web.

Re: prepping the block surfaces and preventing internal engine contamination while doing so: we used plastic scrapers and spray solvents to do the worst of the prep. Finished up with wiping with progressively cleaner cloths, until satisfied. One could try stuffing the passages with rag while the engine's opened, but we didn't do that, just tried to keep the dirt to a minimum, wiping away any seen as soon as it was. Clean the top edge of the block early on, and little will fall there-after. Best to do an oil change shortly after the HG replacement, that should take care of most of what may be left.

We prepped our heads similarly, but started with a varsol bath. Then plastic scraper and solvent, until nothing was left to catch a fingernail on. We then checked the heads for flat using a GOOD straight-edge, strongly backlit, on straights, perpendiculars and diagonals. Both my heads were dead-flat.

Good luck to anyone else trying this. It's deep and involved, but not difficult, as long as nothing's seized. Two of us took 15 hours, from drive-in to drive-out. It was kinda fun!

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Sorry to ressurect an old thread, but the HG issues continue.

I just finished the HG and timing belt on our 2006 2.5I MT and thought I could add some things I discovered that could be helpful.

You do not have to evacuate the a/c or p/s systems. They will fit in the wheel wells and you can hold the a/c pump with bungies. If you move the p/s pump I think it is almost mandatory to pick up a new p/s return line o-ring where the plastic fitting goes into the pump. If not you will foam the fluid and have to wait till the o-ring is replaced to run the motor enough to see if you did a decent rebuild.

You can remove the engine without removing the manifolds before removal.

You can remove the intake manifold without removing the injectors or other components. This really saves time on the reassembly. There are about 10 connectors which need to come off, a coolant pipe and a fuel line.

The crank pulley is located with a key way and is not a taper fit. If it is stiff, some penetrating lubricant and wiggling will get it off. It takes some persuasion though.

Do not re-use your old head bolts. Our's had stretched about 1/8 of an inch longer then the replacements.

Here is a great video on refinishing the head and block surface for re install. Subaru has a TSB about this as well, but the recommend the wizz wheel. As the video shows, this might not be a good idea. I wet sanded the surfaces and obtained a very good result. The grits recommended are 220, 400 and 600 wet or dry.

Prepping your head for new gaskets video: Subaru Head Gasket Repair :

I used the 6 star gaskets. I bought a complete kit with all seals, incl the oil tube seals.

Overall the job took about 10 hours total. 3 hours to remove the enging, 4 to r/r the heads and timing belt and 3 to install.

Here are some pics to help out.

The show the main electriccal disconnect, the engine out of the vehicle, high powered 1/2 hp replacement motor (Joke) and the power steering returne line.


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2002 Outback 2.5 MT5 172k

My head gasket blew back in June sometime with an internal leak causing overflow to bubble and fill all the way up with coolant and I can now see oil residue on drivers side headgasket seam and I am finally getting around to it after parking it and working on suspension on and off this summer. I am going to go for the remove from underneath method. So far I have the timing belt stuff all off, waterpump off, valve covers off, intake manifold bolts loose with the manifold moving freely up and down on the drivers side but it only goes up a little on the passengers side so I need to look into that. Not sure how much room I need.

I need to remove the motor mount bolt up top and bolts down below as per instructions. Also need to remove exhaust manifold bolts...they look very rusted so I am worried. The exhaust hanger I haven't even looked at but I am sure I will break it if I try to loosen it so that is part of the plan.

I can't get a socket around the front spark plug on the drivers side. I think a piece of rubber from my old spark plug wire is stuck down there from a wire and plug swap last March during a road trip - on the side of the road. My plan is to remove head and then try to fish it out of there. What a son of a bitch.

I did the timing belt at 100k on this car but didn't replace the pulleys then so this time I bought the complete gates timing belt kit with new pulleys and tensioners, subaru water pump, thermostat, subaru gaskets, the Genuine Subaru 11044AA642 GASKET CYLINDER HEAD for turbocharged models in order to get MLS- I hope these will work, subaru intake and exhaust manifolds, subaru valve cover manifold gaskets and new washer gaskets for holding bolts and spark plug tube gaskets...among other things.

Here is a couple pictures from the end of my first day of wrenching:
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2002 Outback 2.5 MT5 172k

Are you working your way to taking the engine out of the car to do the work,...or are you trying to do it in the car?
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