[silen7guardian]

Background:
I recently had an issue with my '05 OB XT 5EAT regarding an oil leak. I had a slow oil leak that looked like it was coming from the oil filter. I tried many possible solutions, including replacing the oil filter. Upon more thorough investigation, it looked like the oil leak was coming from just above the oil filter. Forum searches suggested issues such as the infamous head gasket leak, etc. but from where the leak was, I wasn't convinced it was a head gasket. I visited a Subaru dealer and asked the parts guy if he was familiar with the issue. He seemed to immediately know what was going on, and told me I needed a new oil cooler gasket. The oil cooler is the cylindrical object between the oil filter and the engine block. I bought one then for just under $10.

This guide is from my memory of doing the repair, so I apologize for any inaccuracies.

What You Need:
• Subaru Oil Cooler Gasket - Part Number: 21370KA001 ($10) Right here on Amazon
• Torque Wrench (capable of yielding 40 ft-lbs of torque)
• Ratcheting Socket Driver
• 12mm Socket*
• 15/16" DEEP WELL Socket (preferably six-point)**
• 17 mm Wrench (for removing the oil pan drain bolt)
• 5 qt. Oil (I used 5W-30 full synthetic. You want synthetic if you have the turbo)
• Subaru Oil Filter (ask for the crush washer with that), if you're due for an oil change.
• 1 Gallon Subaru Coolant/Anti-Freeze
• 1 Bottle of Subaru Coolant Conditioner
• 1 Gallon Distilled Water
• 1 One-Gallon Milk/Water Container (for mixing water and coolant)
• 2 Funnels
• (Optional) Coolant Evacuator System
• Various different sized needle-nose pliers
• Phillips #2 Screwdriver (for draining the coolant)
• Oil Drain Pan
• Coolant Drain Pan
• Lots of brake parts cleaner
• Foaming Engine degreaser
• Jack Stands (or a lift)
• Lots of shop towels
• Safety Glasses
• Muck-Bucket

* I'm going from memory here, but this will be whatever size is necessary to remove the engine under-cover
** I'm not sure what the actual size is. I suspect it is actually a metric value. I did not have a metic socket large enough and deep enough to remove the oil cooler connector, but the 15/16" socket allowed me to successfully remove and re-install the oil cooler connector

0. Look at the attached pictures. Download the Subaru instructions (PDF). Read through everything first, just in case. Unfortunately I have no picture of the actual oil cooler connector since I accidentally deleted that one, but I've got pictures of pretty much everything else.

1. Lift the car (jack stands, lift, etc.) and remove the engine under-cover.

2. (Optional) Use the foaming engine degreaser around the oil cooler.

3. Drain the engine oil (I won't go into detail on how to do that in this thread). Also remove the oil filter.

4. Drain the coolant. Look in your vehicle's owner manual for specific instructions on how to do this. For the '05 MY, there was a service bulletin stating that it is best to use a vacuum/evacuator system for draining and filling the coolant.

5. Place a muck-bucket underneath where the oil filter goes. Disconnect the two lines connected to the oil cooler. One line is for coolant, and the other is for oil. As you are disconnecting these lines, bear in mind that you will have to re-connect them later. Disconnect the lines in locations where it would be easiest for you to hook them up again. This will be a bit tricky with the exhaust heat shields in the way. It may be helpful to loosen the oil cooler part way first (see step 6) to give yourself more wiggle room.

6. Using the 15/16" deep-well socket and a socket driver, loosen and remove the oil connector. As the oil cooler connector also holds up the oil cooler, be careful that the oil cooler doesn't fall.

7. Remove the old oil cooler gasket. Clean off everything (on the oil cooler AND on the bottom of the engine where the oil cooler goes) with brake parts cleaner and shop towels. It is important that there is no dirt, dust, or debris on the oil cooler, especially where the oil cooler gasket will go. In my case, it looked like there was debris between the oil cooler gasket and the engine block. That presumably caused enough of a gap for a little oil to squirt out, hence my leak.

8. Smear a thin layer of clean engine oil on new oil cooler the gasket. It might slowly start to expand a bit. Place the new oil cooler gasket in its place on the oil cooler. Life the oil cooler up to its place under the engine, put the oil cooler connector in the oil cooler, and start screwing in the oil cooler connector by hand. Leave it a little loose so you can connect the oil and coolant lines more easily.

9. Re-connect the oil line and the coolant line to the oil cooler. Re-install the oil pan drain bolt and the coolant drain plug, if you haven't already.

10. Using the torque-wrench and the 15/16" deep-well socket, tighten down the oil cooler connector. For my vehicle, the correct torque value is 40 ft-lbs.

11. Install the new oil filter (or replace the old one if you were not due for an oil change).

12. Fill the engine with oil. This will be in the neighborhood of 4.5 quarts of oil.

13. Fill the coolant system with a 50/50 mix of distilled water and Subaru coolant. Be sure that a full bottle of Subaru coolant conditioner makes it into the cooling system.

14. Run the engine as described in the owner's manual for when changing the engine coolant (it probably says something like, "Run the engine for about five minutes at 2000 to 3000 RPM. Allow engine to cool. Check coolant level"). Then check the following after the engine has cooled down again:
• Oil level
• Coolant level
• Look for coolant leaks
• Look for oil leaks
• It would be wise to check all of your other fluids while you're here!

15. Done! Keep an eye on your fluid levels and on the bottom of your engine for a while.

 

[silen7guardian]

NOTE: In my labeled photos, I may have reversed the oil and coolant line labels. The procedure is the same though.

 

[CNY_Dave]

Both lines are coolant lines, the oil passes through the center bolt and the holes on the middle of the 'donut'.


Dave

 

[silen7guardian]

Oh, thank you. Haha, before February when I got the car I didn't know ANYthing about cars (except how to drive them), so I am definitely learning as I go.

Any corrections, tips, or insights are quite welcome here!

 

[ckOBXT]

I'm pretty sure I have this same issue. I have a coolant/oil mixture dripping from the bottom of my oil filter, and I can see it on the oil cooler as well. Out of curiousity did you have any burning coolant or oil smells going on when you had this problem? Great write up-Thanks.

 

[silen7guardian]

Head Gasket

I have a coolant/oil mixture dripping from the bottom of my oil filter, and I can see it on the oil cooler as well. Out of curiousity did you have any burning coolant or oil smells going on when you had this problem?

I didn't have any issues with coolant loss (and still don't, thankfully). The faulty gasket I replaced only resulted in oil loss. The oil cooler assembly has coolant running through it, but coolant would only have leaked from here if the respective coolant hose clamps were loose or the hoses had been punctured/torn.

Based on my limited knowledge, I would guess that you have a head gasket leak, and that your oil and/or coolant is dripping from the head gasket down onto the oil filter.

Regarding smells: I never smelled coolant. I did smell oil (more of a "warm oil" than a "burning oil" smell, if that makes sense). I still continue to smell oil even after the repair if I go above 3500 RPM or so, which has been paining me, but that's another story.

Get some foaming engine degreaser and some safety glasses. Clean all traces of oil off your motor so that any new oil leakage will be obvious. When your motor is clean and dry, drive around a bit and see if you can pin-point where the leak comes from.



A head gasket leak might also explain the faint exhaust smell. You mentioned that you fixed a coolant leak before. Where was the coolant coming from (or how did you fix it)?

I'm curious: What is all that yellow-looking dust on the intake manifold in the picture you attached to your other post?

2005 OB XT, Auto, 70K. My OB has a smell coming through the ventilation system when I'm stopped and idling. Smells like exhaust or burning grease, it is somewhat faint. It doesn't do it when the recirculation is on, only when fresh air is on. No torn boots (fixed them), no leaking coolant that I can see (fixed this). I did clean the engine off well, but still stinks. In fact you can smell it when you open the hood. I did notice some greasy gunk on the rubber gasket connecting to the turbo (front side-not sure what that part is??), and some oily/greasy gunk directly above the oil filter. I cleaned it, but it still stinks (so it’s probably still leaking). Any suggestions!!!

 

[Seabass]

Nice write up. It seems to be a very common problem.

 

[ckOBXT]

OK I took a good look at the problem. I appear to have 2 leaks. Coolant on the Drivers side. That appears to be running off the bottom of the Coolant reservoir. The 2nd leak is posted in the photos. This is either from the oil cooler gasket, or as you mentioned the head gasket. I have oil spray clear above the oil cooler gasket (pretty much everywhere around it, and a fair amount of oil on the front coolant line. Take a look at let me know any opinions. Fingers crossed that its not the head gasket.

 

[ckOBXT]

Here is the coolant leak on the Driver's side. I thought the head gaskets issues were resolved in the XT's. Thoughts????

 

[silen7guardian]

Head gasket failure became significantly less common on models after 2002 or so, but as with all car parts, there is still the possibility of failure. Oil gets sprayed all over with air turbulence from when you're driving faster, so that's why it would be a good idea to spray engine degreaser around the oily areas. You want to know beyond a guess where the oil is coming from.

That said, now that I know that your fluids are leaking from two different places, it's probably not a head gasket. It sounds like one of your leaks is the oil cooler gasket. It's pretty common on these models, I would guess. When I went to a Subaru dealer to ask about the problem, the conversation with the guy at the parts window went like this:
"I have an oh-five Outback with an oil leak somewhere around the oil filter, and—"
"Oh, yea. You need an oil cooler gasket. I'll be right back."
"Uh, thanks!"

The coolant is potentially a trickier question. In another thread you said you had an issue with a coolant leak before, and that that you fixed it. Was that this vehicle? What was the issue; how did you fix the leak before?

These are my guesses. Others, feel free to chime in.
1. It may be a leaky reservoir. Take it out and check for leaks.
2. It may be that your reservoir is too full, and overflows when your engine heats up.
3. Your reservoir may be a little too full, and bubbling over when you drive. Do you see bubbles in the reservoir after driving a while? I seem to recall that bubbles in the coolant reservoir are a sign of head gasket failure.
4. Check all your coolant hose clamps. Also check your hoses to make sure they're not too spongey.

That's all I can think of at the moment.

 

[ckOBXT]

FYI--I move this thread to the Problems and Maintenace to keep the moderators happy.

Lower Radiator hose was leaking, just replaced it. I have a feeling the reservoir is bad also. I've got my oil cooler gasket on order, that should be fixed this week. The previous problem was with the turbo inlet tube. Something had been leaking on it (I'm guessing coolant), and caused it to fall apart. I replaced it, and tighten down all the clamps. No more problems with that. Thanks again for the help.

 

[silen7guardian]

FYI--I move this thread to the Problems and Maintenace to keep the moderators happy.

Lower Radiator hose was leaking, just replaced it. I have a feeling the reservoir is bad also. I've got my oil cooler gasket on order, that should be fixed this week. The previous problem was with the turbo inlet tube. Something had been leaking on it (I'm guessing coolant), and caused it to fall apart. I replaced it, and tighten down all the clamps. No more problems with that. Thanks again for the help.

You're welcome! I'm glad you found the problem. :29:

 

[ckOBXT]

I had two issues. Lower Radiator hose leaking (just fixed) and Oil Cooler Gasket (fixing tonight). The previous issue was from coolant leaking on the turbo inlet tube, causing it to fall apart. Replaced it, tightened the hoses and no more problems. Thanks for the write up and help.

 

[Tneville]

Thanx!

Great post. I just picked up a 2002 Outback, H6 LL Bean, and noticed a small puddle of oil on my driveway once it was parked. I was afraid it might be the rear main seal, but it didn't appear the location of origin. BIG sigh of relief finding out about the oil cooler gasket issue! This I can deal with. Thanx again.

 

[silen7guardian]

Great post. I just picked up a 2002 Outback, H6 LL Bean, and noticed a small puddle of oil on my driveway once it was parked. I was afraid it might be the rear main seal, but it didn't appear the location of origin. BIG sigh of relief finding out about the oil cooler gasket issue! This I can deal with. Thanx again.

You're welcome! While you're working, be sure to check for other leaks, too. Valve cover gaskets often need to be replaced on older vehicles and can drip around the same area on an Outback. On mine, the cam shaft crank seals are also leaking, which results in oil leaking from the timing belt cover. I seem to recall the H6 has a timing chain instead of a timing belt though, so I imagine that's not an issue for you. Another issue with my vehicle was that the power steering return hose was leaking slowly right above the same general area. That was an easy fix though- a screw hose clamp took care of that. I also had a leaking CV axle boot.

 

[impreza_rs_2004]

Background:
I recently had an issue with my '05 OB XT 5EAT regarding an oil leak. I had a slow oil leak that looked like it was coming from the oil filter. I tried many possible solutions, including replacing the oil filter. Upon more thorough investigation, it looked like the oil leak was coming from just above the oil filter. Forum searches suggested issues such as the infamous head gasket leak, etc. but from where the leak was, I wasn't convinced it was a head gasket. I visited a Subaru dealer and asked the parts guy if he was familiar with the issue. He seemed to immediately know what was going on, and told me I needed a new oil cooler gasket. The oil cooler is the cylindrical object between the oil filter and the engine block. I bought one then for just under $10.

This guide is from my memory of doing the repair, so I apologize for any inaccuracies.

What You Need:
• Subaru Oil Cooler Gasket - Part Number: 21370KA001 ($10)
• Torque Wrench (capable of yielding 40 ft-lbs of torque)
• Ratcheting Socket Driver
• 12mm Socket*
• 15/16" DEEP WELL Socket (preferably six-point)**
• 17 mm Wrench (for removing the oil pan drain bolt)
• 5 qt. Oil (I used 5W-30 full synthetic. You want synthetic if you have the turbo)
• Subaru Oil Filter (ask for the crush washer with that), if you're due for an oil change.
• 1 Gallon Subaru Coolant/Anti-Freeze
• 1 Bottle of Subaru Coolant Conditioner
• 1 Gallon Distilled Water
• 1 One-Gallon Milk/Water Container (for mixing water and coolant)
• 2 Funnels
• (Optional) Coolant Evacuator System
• Various different sized needle-nose pliers
• Phillips #2 Screwdriver (for draining the coolant)
• Oil Drain Pan
• Coolant Drain Pan
• Lots of brake parts cleaner
• Foaming Engine degreaser
• Jack Stands (or a lift)
• Lots of shop towels
• Safety Glasses
• Muck-Bucket

* I'm going from memory here, but this will be whatever size is necessary to remove the engine under-cover
** I'm not sure what the actual size is. I suspect it is actually a metric value. I did not have a metic socket large enough and deep enough to remove the oil cooler connector, but the 15/16" socket allowed me to successfully remove and re-install the oil cooler connector

0. Look at the attached pictures. Download the Subaru instructions (PDF). Read through everything first, just in case. Unfortunately I have no picture of the actual oil cooler connector since I accidentally deleted that one, but I've got pictures of pretty much everything else.

1. Lift the car (jack stands, lift, etc.) and remove the engine under-cover.

2. (Optional) Use the foaming engine degreaser around the oil cooler.

3. Drain the engine oil (I won't go into detail on how to do that in this thread). Also remove the oil filter.

4. Drain the coolant. Look in your vehicle's owner manual for specific instructions on how to do this. For the '05 MY, there was a service bulletin stating that it is best to use a vacuum/evacuator system for draining and filling the coolant.

5. Place a muck-bucket underneath where the oil filter goes. Disconnect the two lines connected to the oil cooler. One line is for coolant, and the other is for oil. As you are disconnecting these lines, bear in mind that you will have to re-connect them later. Disconnect the lines in locations where it would be easiest for you to hook them up again. This will be a bit tricky with the exhaust heat shields in the way. It may be helpful to loosen the oil cooler part way first (see step 6) to give yourself more wiggle room.

6. Using the 15/16" deep-well socket and a socket driver, loosen and remove the oil connector. As the oil cooler connector also holds up the oil cooler, be careful that the oil cooler doesn't fall.

7. Remove the old oil cooler gasket. Clean off everything (on the oil cooler AND on the bottom of the engine where the oil cooler goes) with brake parts cleaner and shop towels. It is important that there is no dirt, dust, or debris on the oil cooler, especially where the oil cooler gasket will go. In my case, it looked like there was debris between the oil cooler gasket and the engine block. That presumably caused enough of a gap for a little oil to squirt out, hence my leak.

8. Smear a thin layer of clean engine oil on new oil cooler the gasket. It might slowly start to expand a bit. Place the new oil cooler gasket in its place on the oil cooler. Life the oil cooler up to its place under the engine, put the oil cooler connector in the oil cooler, and start screwing in the oil cooler connector by hand. Leave it a little loose so you can connect the oil and coolant lines more easily.

9. Re-connect the oil line and the coolant line to the oil cooler. Re-install the oil pan drain bolt and the coolant drain plug, if you haven't already.

10. Using the torque-wrench and the 15/16" deep-well socket, tighten down the oil cooler connector. For my vehicle, the correct torque value is 40 ft-lbs.

11. Install the new oil filter (or replace the old one if you were not due for an oil change).

12. Fill the engine with oil. This will be in the neighborhood of 4.5 quarts of oil.

13. Fill the coolant system with a 50/50 mix of distilled water and Subaru coolant. Be sure that a full bottle of Subaru coolant conditioner makes it into the cooling system.

14. Run the engine as described in the owner's manual for when changing the engine coolant (it probably says something like, "Run the engine for about five minutes at 2000 to 3000 RPM. Allow engine to cool. Check coolant level"). Then check the following after the engine has cooled down again:
• Oil level
• Coolant level
• Look for coolant leaks
• Look for oil leaks
• It would be wise to check all of your other fluids while you're here!

15. Done! Keep an eye on your fluid levels and on the bottom of your engine for a while.

This was a great write up I had to replace that o ring on my 2007 outback H6. the only thing is where it say to take off the oil filter connector use a 15 or 16 mm socket it was a 24mm deep socket on mine. thanks for the write up

 

[silen7guardian]

This was a great write up I had to replace that o ring on my 2007 outback H6. the only thing is where it say to take off the oil filter connector use a 15 or 16 mm socket it was a 24mm deep socket on mine. thanks for the write up

10. Using the torque-wrench and the 15/16" deep-well socket, tighten down the oil cooler connector. For my vehicle, the correct torque value is 40 ft-lbs.

Thanks!

For the sake of learning, I would like to point out that 15/16" would be read as fifteen-sixteenths of an inch. The double-quotation mark after a numerical value will typically mean that it's a measurement in inches. It looks like I can't edit the original post, or I'd change it. In retrospect, I should have just Googled it or done the math when I originally made the walk-through. IIRC, one inch is 25.4 millimeters, so (15/16)*25.4mm = 23.8mm, which is effectively 24mm. Oh, well... I learn as I go, I guess.

 

[impreza_rs_2004]

Thanks!

For the sake of learning, I would like to point out that 15/16" would be read as fifteen-sixteenths of an inch. The double-quotation mark after a numerical value will typically mean that it's a measurement in inches. It looks like I can't edit the original post, or I'd change it. In retrospect, I should have just Googled it or done the math when I originally made the walk-through. IIRC, one inch is 25.4 millimeters, so (15/16)*25.4mm = 23.8mm, which is effectively 24mm. Oh, well... I learn as I go, I guess.

oh no worries thanks for the write up it was a very big help becasue I had no clue where the leak was coming from. and no clue of to fix it.

 

[Chue]

Can the oil cooler gasket be changed with the oil line and coolant line still attached to it? I just changed my oil 3 days ago. I notice it was leaking around the gasket and ened up going to the dealer after oil change. Dealer confirm it was the oil cooling gasket. I bought the gasket from them for $10 from them attempting to change it myself. I don't want to recharge my oil if I don't have to?

 

[GI Joe]

Can the oil cooler gasket be changed with the oil line and coolant line still attached to it? I just changed my oil 3 days ago. I notice it was leaking around the gasket and ened up going to the dealer after oil change. Dealer confirm it was the oil cooling gasket. I bought the gasket from them for $10 from them attempting to change it myself. I don't want to recharge my oil if I don't have to?

I replaced my oil cooler O-ring a couple weeks ago, Without draining Coolant, but I doubt you could get by without draining oil.. You could do it, I suppose and just drain/lose whatever comes out of the oil filter area, and not drain the whole pan....

I was in the midst of an oil change, so my oil was completely drained, although I didn't feel like draining coolant, After a recent water pump/coolant swap job. I took the 90* coolant line off the oil cooler, and plugged the rubber end(still attached to the engine) with an appropriate sized bolt, 1/2"?) and then just plugged the other end with my thumb. It was a little tight to get the cooler rotated so I could clean the topside and the mating surface on the engine, especially with one hand, but I felt it was worth it to save from the hassle of losing fresh coolant. I spilled very Minimal coolant going this route(not even enough to need to top it off)!.

Obviously make sure everything is completely cooled off before attempting, as you'll be Very intimate with the exhaust/engine parts...
Thank you to those that have posted about this, and Good luck to those attempting!!! it's not that bad!!!:29: