Subaru Outback Forums banner

09 Finally time to do the head gaskets.

16K views 57 replies 12 participants last post by  SonicDeathMonkey 
#1 ·
So after 172,000 miles I will finally be removing the engine to replace the factory head gaskets. Whats been just a wet spot on the block for about the last 60,000 miles has finally turned into a dime sized spot on the garage floor if it sits for a while. While I'm doing the gaskets and resurfacing the heads I just want a list of other things to tackle while the engine is out. So far I've done the timing belt at 90k, and a new clutch at 160k (not because the clutch was slipping but for the bad throw out bearing subaru uses), both front cv boots tore and were replaced, all new wheel bearings whenever they went out, valve cover gaskets around 80k, new pcv valve, spark plugs and radiator flush. So here's my list of things to do while its out. Any other suggestions?

Head gaskets (going with the 11044AA642 unless i need the 11044AA770 I still haven't found a clear answer as to which one to use with the 09. Going off looks it think the 642.
Intake gaskets
cam seals
new head bolts
spark tube seals
water pump
water pipe o rings
timing belt
serpentine belts
valve cover gaskets
spark plugs
plug wires
dipstick o rings
02 sensors
 
See less See more
#2 ·
The oil pressure sensors mounted on the heads will probably need replacing too. (1 for for each side)The seals went bad on my 2008 carefull not to over tighten these as the may crack the where it mounts on the head.


Is there something going on with the exhaust that is causing you to replace the. O2 sensors ?


Sent from my iPhone using Tapatalk
 
#4 ·
It's mostly complete on your list. With the timing belt change, also replace the tensioner and the idler bearings.

And this is the first head gasket work? I don't know of any Gen 3 H4 2.5i NA that has made it this far on the original HGs without needing replacement; you might well hold the record so far!

Failure log here:

 
#56 ·
It's mostly complete on your list. With the timing belt change, also replace the tensioner and the idler bearings.

And this is the first head gasket work? I don't know of any Gen 3 H4 2.5i NA that has made it this far on the original HGs without needing replacement; you might well hold the record so far!
210,000 - Ripped the engine out yesterday. :)
 
#5 ·
Yes original head gaskets. I’ve owned the car since new and besides what I mentioned in the first post I just kept up with the regularly scheduled maintenance knowing that I would have to do them eventually. Timing belt was replaced with a whole kit at 90k and I plan on doing a whole kit this time around.
 
#6 ·
I used the FEL-PRO HS26415PT1 kit which has a lot of the things you'll replace while you're already in there. It's $80 more than the MLS headgaskets themselves so it may be cheaper to buy the additional parts piecemeal.
As mentioned, timing belt tensioners and all pulleys for the TB plus crankshaft seal, upper and lower radiator hoses, thermostat. The water pump is optional and only if you get another Asin pump. If you use a Chinese pump, be prepared to replace it within the next 5 years (I made that mistake with a Chinese built pump that was part of the AC Delco TB kit, it started leaking after 4 years). Of course, while you are removing them, you might as well replace the accessory belts.
 
#8 ·
I’ve got the parts for the oil seperator plate, was going to do it with the clutch but saw no signs of leaking but I’ll do it anyway. Did the real main deal with clutch, saw signs of seeping. Doing the front crankshaft seal this time. Got a Subaru water pump, all parts I went with genuine oem for that matter.
And just as I was about to sing praises for the reliability so far I’m dead on the side of the road with what is reading a bad cam position sensor so waiting on a tow home. Engine just died on the freeway will crank but no starting so added the sensor to my order.
 
#34 ·
489096

489097
489098
489099

Well got to the left side tonight, all four exhaust valves bent, not much hope for the right. Gasket looks pretty good for 172k. Looks like it’s running rich or oils getting past the rings. I am consuming about a qt every 1000 miles is this something I could look into while the engines out? Going to do the right side tomorrow.
 
#35 · (Edited)
Looks like it’s running rich or oils getting past the rings. I am consuming about a qt every 1000 miles is this something I could look into while the engines out?
I don't know, do you really want to get into the bottom end on an engine with 172k on it?

Do realize that with new head gaskets, valve cover gaskets, spark plug tube seals, cams end gaskets, etc. you'll invarably tighten things up a bit and reduce consumption a little. How much remains to be seen.

My 2008 2.5i NA at 145k miles uses maybe a quart in 4,000 miles, but it's not evenly using it across the oil change interval - it's more like none the first 2k, then the one quart over the last 2k before I change it. I've decided I'll live with it, and by the time I reach 172k, it may well be consuming oil at your rate.

Good photo documentary you've offered here, BTW.

Not a smoking gun by any means but a lot of seepage around hydraulic tensioner.
I'd say it's likely your smoking gun. How does the backpressure on it feel?

And inquiring minds would like to see which manufacturer's mark is on that thing, can you see any?
 
#38 ·
No country of origin stamp on tensioner but has jap bearings, and still got some good amount of force to it at least not enough to move it by hand but that’s about all the effort I put into it.
489162
489163


All four valves bent in cylinder 1, intakes bent in cylinder 3. Grand total of 10 bent valves for those of you counting at home.
 
#39 ·
Going off price and further inspection I'm just going to go with all new valve seals and new valves to replace broken ones, no piston rings. Also for-going new 02 sensors for about 120 a piece. Things are starting to add up. Plus I have to now replace the blown out timing belt cover and to make matters worse my kid dropped the harmonic crankshaft pulley chipping off a piece, used on ebay for $30 bucks but still. Valve seats look good, I'll just lap all the valves while they're all out, leak down test showed a little seepage even for the good valves. Hopefully thats its. Any other recommendations?
 
#41 ·
11044AA770 OR SET of 2, Genuine Subaru MLS Head Gasket For 2002-2005 Impreza, WRX EJ205 TURBO | eBay

Fit 06-12 Subaru Impreza 2.5L SOHC Mitsuboshi Timing Belt NPW Water Pump EJ253 | eBay NPW is a Japanese manufacturer

Valve seals, valve cover gaskets, tube seals, intake and exhaust gaskets - I recommend you get them from Subaru or use Mahle or Beck Arnley. One reason is fitment. Second is product design. For instance the exhaust manifold gasket from FelPro is a coated aluminum sheet where the other 3 manufacturers design the gasket with a compression ring for the ports. FelPro intake gaskets are too long and do not fit the guide pins proper which makes the gasket bow up in the middle and will create a vacuum leak when you torque the manifold down. The cam and oil pump/crank seals from FelPro do not fit as tight as the OEM style and the valve cover gasket is always too small.

You could probably find a HG kit online that has quality seals and gaskets. Just stay away from FelPro. Trust me.

A timing cover would run about $45 from Subaru.

As for the oil in the combustion chamber - Your PCV valve is probably restricted. This allows for higher crankcase pressures and the oil gets past the rings easily. Clean or replace the PCV valve, clean the intake out, clean the throttle body, check the EGR ports for carbon build up and clean the carbon from the top of the pistons. That carbon in the combustion is what assist in creating detonation which means the fueling for the car is changed and adds to the carbon.

I suggest Royal Purple. 2 reasons - 1. It's a great synthetic and you can run 5-10k miles interval as long as you change the filter every 5k and keep it full. 2. You won't be adding much oil between changes. Every one of my Subies runs 5W30 RP and not one of them is using oil, (the Impreza is leaking it but I don't drive it much - waiting on time to pull the engine and repair it). Years back I put up a poll on oil consumption vs brand and it seemed like Mobil1 was the biggest loser. I think Valvoline had good results. Either way, using synthetic is actually lower cost over time for oil changes and maintenance cost, like carbon build up and wear.

Make sure you have the gap set proper on the belt guide above the crank gear. All that shredding of the belt is probably from long term contact with the guide.

Make sure the cooling system is burped good. When the cooling system is air free, do a throttle relearn after it's cooled down and sat for a few hours; takes about 25 minutes. You can Google it or search YouTube.

Otherwise you have a good grasp on it.
 
#43 ·
489217

Picked up the first batch of parts I was going to originally need. All genuine suabru from the dealer, except for oem mitsuboshi belt kit from six star bernie. Went with the 11044AA642 gaskets, and they look like a perfect fit.

Just placed second order of valves and seals and such to suabru. I did get a new PCV valve which was just going to be replaced anyway.

I'll try that oil. I was using mobil 1 for a while which is when I noticed the consumption issues which makes sense based on your poll. I switched back to dino and never looked back, so I'm interested to see how it runs with essentially an entire rebuilt top end.

When I did the gates kit I just used that little plastic guide to install timing belt guide and never bothered to check the gap to my manual so i'll be sure to do that this time.
 
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