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Discussion Starter · #1 ·
Hi there!
I am a new outback owner (I used to have an 05 2.5rs) I bought an 09 2.5i limited outback a few months ago. It had 147k, clean title and the dealer I bought it from said he just replaced the hg’s, timing belt, exhaust manifold gaskets and valve cover gaskets. I brought it home (4 hours away) and I noticed the temperature gauge was moving around. I’d put it under load and it would drop rapidly to the cool range. I got it home, the coolant reserve reservoir was empty, thought there might just have been some air bubbles in the system and topped the coolant. Replaced coolant temp sensor and that solved the temp gauge roaming around, but it was still losing coolant. Took it to a mechanic for a complete inspection, passes compression test and gets a clean Bill of health. Then the p0420 code popped up. Within a week of the p0420 code popping up, I went to start it and it’s sputtering, misfire codes (301 & 302 if I remember right), major failure of TAC code. I let it sit with the battery disconnected for an hour and it seemed to run fine, took it to mechanic and it failed the compression test and had air bubbles in coolant. They diagnose it as failed hg. Took it home and have been driving it close to home and it’s running perfect. (I don’t trust it one bit so I don’t leave the neighborhood) Here’s where things get interesting: Tore down the motor this weekend and everything looks fine. Brand new gaskets, timing belt, everything appears to be done correctly. We’re scratching our heads now. Any ideas?? I’ve looked through the forum but haven’t found a thread with this situation! Thanks in advance!!!
-Nicole
 

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Hi there!
I am a new outback owner (I used to have an 05 2.5rs) I bought an 09 2.5i limited outback a few months ago. It had 147k, clean title and the dealer I bought it from said he just replaced the hg’s, timing belt, exhaust manifold gaskets and valve cover gaskets. I brought it home (4 hours away) and I noticed the temperature gauge was moving around. I’d put it under load and it would drop rapidly to the cool range. I got it home, the coolant reserve reservoir was empty, thought there might just have been some air bubbles in the system and topped the coolant. Replaced coolant temp sensor and that solved the temp gauge roaming around, but it was still losing coolant. Took it to a mechanic for a complete inspection, passes compression test and gets a clean Bill of health. Then the p0420 code popped up. Within a week of the p0420 code popping up, I went to start it and it’s sputtering, misfire codes (301 & 302 if I remember right), major failure of TAC code. I let it sit with the battery disconnected for an hour and it seemed to run fine, took it to mechanic and it failed the compression test and had air bubbles in coolant. They diagnose it as failed hg. Took it home and have been driving it close to home and it’s running perfect. (I don’t trust it one bit so I don’t leave the neighborhood) Here’s where things get interesting: Tore down the motor this weekend and everything looks fine. Brand new gaskets, timing belt, everything appears to be done correctly. We’re scratching our heads now. Any ideas?? I’ve looked through the forum but haven’t found a thread with this situation! Thanks in advance!!!
-Nicole
It is quite possible that the HG replacement just wasn't done correctly. Were the heads AND the block checked for warping? What type and brand of HG was installed? Were the surfaces prepped properly? Were the original head bolts reused? * I know "the book" says you can reuse Subaru head bolts. I say BS! I don't care if they are TTY or not, you will never get the proper clamping force on a used head bolt*

Unfortunately, when it comes to head gaskets, if you screw one thing up, or cheap out on the gaskets, or the machine shop ... they will fail again.

One thing I have seen pushed around the internet is that you "can" do a HG job on a Subaru without removing the engine. And I am sure you "can" ... but can you do it right?
 

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Outback 2011 3.6R Premium
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2,284 Posts
Sorry that you are having this trouble with your Outback.

The cooling system holds around 6 quarts and any part of the system that is not working correctly can cause an overheating event.

It sounds like your mechanic may have misdiagnosed the problem which is now going to cost more than expected to remedy.

I would be looking at the radiator (are there broken fins or blocked cores), the thermostat and radiator cap (are they Subaru or cheap/poor quality aftermarket).

There are many causes that can lead to overheating and sometimes people jump to the worst case scenario without properly diagnosing the problem.

As you are redoing the head gaskets, make sure you use Multi Layer Steel gaskets AND get the heads machined to ensure they are flat. You also need to make sure the surface of the block is properly cleaned of all old gasket etc to prevent another head gasket leak.

Oh, and you can re-use the head bolts. All Subaru technicians at dealerships re-use the head bolts so that is good enough for me (I have not had a failure re-using them either)

Seagrass
 
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01 VDC, 05 R Sedan, 06 BAJA EJ257
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I've reused head bolts on all the boxers. Never a problem. Coat with oil, install, torque.

MLS is the way to go. Use the EJ255 torque specs and get that last turn right.

Non-OEM thermostats cause problems, as well as non-OEM radiator caps. The aftermarket stats don't allow enough coolant flow. The aftermarket caps vent too early and the coolant goes in to the res, spills over, then when you shut it down it pulls all the coolant from the reservoir leaving it empty. A few drives with this going on and you get a low system and hotter temps.

If the engine was "repaired" with SLS gaskets, not torqued properly, air left in the system, one overheat situation will breach a gasket.

Since your misfires were on opposing cylinders, you may want to check the coil pack. While your at it, make sure the battery is good and the grounding has good conductance.
 

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Discussion Starter · #5 ·
Update: we replaced the hg’s with the fel-pro kit and new bolts. The fel pro gaskets had a slightly different design than the gaskets we removed, which was interesting. Had a few, easily fixed hiccups, but got her purring again and she’s on her maiden voyage as we speak. Thank you both for your responses! More info the better, It gave us some great leads!
-nic
 
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