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2004 Subaru Outback, 2005 Subaru Outback Ltd, and a 2006 Subaru Impreza WRX TR
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Discussion Starter #1
Hi all,

Looking for some feedback on a recent HG job.

Car Info
2007 Subaru Outback Ltd (NOT CA emissions)
2.5L 4cycl, Automatic
131,500 miles

So, I just replaced the HGs in this car. This is the 3rd HG job I've done (I buy em cheap and flip em for profit). No issues to-date (including on my '04 Outback, with 265k miles, 50k mile since I replaced the HG).

In this '07, I pulled the motor and replaced every hose, belt, gasket you possibly can. Used the Gates TB + Water Pump kit, felpro MLS gaskets, new cylinder head bolts (followed torque specs and procedures), etc. I had the cylinder heads machined at a professional machine shop (they've done all 3 sets for me, and are great quality).

Here's the issue...after putting everything back together, I have a serious problem. The car blows a thick cloud of white smoke out of the driver side tail pipe. It idles fine, but when you rev above 2500 rpms, it starts to choke and die out. When I took it for a spin, it choked and died after about 0.5 miles. Let it rest, started it back up, and drove it back home. Revved it to 3000 rpms and held it, and the car choked and died again in less than a minute. Smelled the white smoke, and I think it smelled sweet. No visible leaks anywhere under the hood.

When I checked the radiator, the coolant was low (had to add about 4oz to fill up, and only had the car running for about 45 mins in total). All signs point to me screwing up the HG job and coolant getting into the cylinder head, but I'm desperate for it to be something else (false hope that a CC is filled with coolant and burning off, i.e. from the original HG issue, but don't think that would cause the motor to stall???).

Looking for advice on how to proceed. I bought a kit that you attach to the radiator and watch to see if a liquid you add bubbles and changes color (from combustion gases getting into the coolant I think). If it is a bad leak in the cylinder head, I am looking for advice on options.

Rather than pull the whole motor again, I was thinking if I could determine which cylinder is leaking that I could leave the motor in, jack it up, and try re-torquing/tightening the cylinder head bolts. This would be pretty easy, since I'd only need to unbolt the motor mounts, exhaust manifold, and jack up the engine to remove the valve covers and access the bolts.

Is the above idea worth it? Obviously if the HG resurface job is bad, that wouldn't help. But I'm desperate to avoid having to pull the motor again...any ideas/similar experiences?

Thanks!
 

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wonder if the short block is truely flat,...

or if there is something not straight or warped by one of the coolant passages.

or at 265,000 miles was this a baked turd that you should not have bothered to do head gaskets on in the first place,.
..vs. finding a less abused matching ej253.
 

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2004 Subaru Outback, 2005 Subaru Outback Ltd, and a 2006 Subaru Impreza WRX TR
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Discussion Starter #3
wonder if the short block is truely flat,...

or if there is something not straight or warped by one of the coolant passages.

or at 265,000 miles was this a baked turd that you should not have bothered to do head gaskets on in the first place,.
..vs. finding a less abused matching ej253.
Just for clarification, this one has 131k miles. My 04 has 265k, and runs great. Never had to do the block before, just cleaned it off with a scraper and carb cleaner.
 

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Just for clarification, this one has 131k miles. My 04 has 265k, and runs great. Never had to do the block before, just cleaned it off with a scraper and carb cleaner.
did you check the short block surfaces with a straight edge?

what was the 07 car doing before you started the job? (typical oil externally, or rare coolant into the oil / exhaust, or rare exhaust gases in coolant.).
 

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2017 Outback, 2.5L, Auto; 2018 Forester, 2.5L, Auto (for Mama); 2005 Baja, 2.5 Turbo, Manual
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Seems like it's blowing enough coolant so you would be able to see it in the exhaust port as you remove exhaust manifold. Then you could check torque on the head bolts, sometimes you get lucky.
But more likely you'll end up pulling the engine to redo the gasket.
Wish you well with it.
 

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Discussion Starter #6
Just for clarification, this one has 131k miles. My 04 has 265k, and runs great. Never had to do the block before, just cleaned it off with a scraper and carb cleaner.
did you check the short block surfaces with a straight edge?

what was the 07 car doing before you started the job? (typical oil externally, or rare coolant into the oil / exhaust, or rare exhaust gases in coolant.).
It was pissing oil and coolant on to the ground. Previous owner was topping it off daily.
 

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Discussion Starter #7
Seems like it's blowing enough coolant so you would be able to see it in the exhaust port as you remove exhaust manifold. Then you could check torque on the head bolts, sometimes you get lucky.
But more likely you'll end up pulling the engine to redo the gasket.
Wish you well with it.
Thanks for the advice. I was thinking it might show up in the manifold when I pulled it.
 

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Did you use a torque angle meter?

I'm not a fan of the new bolts. I always reuse the old ones when possible. No need for the crazy torque sequence that way.
 

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Discussion Starter #9
Did you use a torque angle meter?

I'm not a fan of the new bolts. I always reuse the old ones when possible. No need for the crazy torque sequence that way.
Yes, I used one. Followed the exact sequence and specs
 

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It was pissing oil and coolant on to the ground. Previous owner was topping it off daily.
where was the coolant coming from to leak on the ground?

any smell in the exhaust then?

what kind of rad cap was on it. ? (when I see a used car with a aluminum engine, with a flip top relief rad cap...it makes me think new engine).
 

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Discussion Starter #12

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Discussion Starter #13
It was pissing oil and coolant on to the ground. Previous owner was topping it off daily.
where was the coolant coming from to leak on the ground?

any smell in the exhaust then?

what kind of rad cap was on it. ? (when I see a used car with a aluminum engine, with a flip top relief rad cap...it makes me think new engine).
Looked to be coming from the bottom of both cylinder heads. Oil as well. No issues with smoke from the exhaust or drivability issues prior to the HG change. I believe that the leak into the cylinder didn't exist until after the HG job. So I'm thinking it's not a cracked block. And the machinist check the heads for cracks and said they looked great. I'd think it is an uneventful surface on the block or bad bolt down on the cylinder head.
 

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A couple of thoughts...

I have seen engines where the block was damaged by someone previously using a scotch-brite pad on die grinder. Aluminum is way to soft to use power tools on.

Another thought, did you make sure the head bolt holes were clear of oil or anything else that could cause the bolts to hydraulic and come up against the fluid? This can at the least mess up the torque, the the worst damage the block.
 

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2005 Subaru Outback 2.5XT Limited 5mt, Champagne, stock power
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If the shop checked the heads for leaks, then it's pretty safe to cross that off the list. I can personally attest to the quality of the fel-pro gaskets, they work very well so either they got scraped on one of the dowels while being put on, or there is some other assembly anomoly/ warped block face. I would also pursue the possibility of the bolts hydrolocking on fluid sitting in the bolt holes. Hope you get this figured out without too much trouble.
 

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Discussion Starter #16
A couple of thoughts...

I have seen engines where the block was damaged by someone previously using a scotch-brite pad on die grinder. Aluminum is way to soft to use power tools on.

Another thought, did you make sure the head bolt holes were clear of oil or anything else that could cause the bolts to hydraulic and come up against the fluid? This can at the least mess up the torque, the the worst damage the block.
Ya, I had heard mixed opinions on scotch brights and sanding the block. All I do is use carb clearner and a blade to scrape off dirt and old gasket material.

Never thought about the bolt holes having fluid in them. I do dip the bolts in oil before threading them, but that's never been an issue. Wonder if I can clean the bolt holes with the motor still in? Maybe I can find a long suction tube. Or is there a better way?
 

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Discussion Starter #17
If the shop checked the heads for leaks, then it's pretty safe to cross that off the list. I can personally attest to the quality of the fel-pro gaskets, they work very well so either they got scraped on one of the dowels while being put on, or there is some other assembly anomoly/ warped block face. I would also pursue the possibility of the bolts hydrolocking on fluid sitting in the bolt holes. Hope you get this figured out without too much trouble.
Thanks for the advice. Never knew about the bolts hydrolocking. Any tips for cleaning them out?
 

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Compressed air is a good way to blow out the bolt holes. Dipping them in oil is good procedure so they torque properly, but everything in moderation. I am always hesitant to use blades on aluminum. I use a green scotch brite pad by hand and just lightly rub over the surfaces with brake cleaner or wd-40 until its clean and shiny. Could have a very small channel in the block face leaking the coolant.
 

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Never thought about the bolt holes having fluid in them. I do dip the bolts in oil before threading them, but that's never been an issue. Wonder if I can clean the bolt holes with the motor still in? Maybe I can find a long suction tube. Or is there a better way?
Dipping them is a bit more oil than I usually put on them. As long as you don't have too much excessive oil, I don't think it would cause a problem.

I usually just blow the holes out with compressed air. I use a rag around the blow nozzle so it doesn't make too huge of a mess.

I use new felpro bolts. I disagree with the members that recommend reusing the bolts. I can say with confidence, using new bolts is not the cause of any problems.
 

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Sounds like the engine was abused.

That said - there's a reasonable chance you could get the leak to stop, so if you feel good about that, sure try to mitigate it. I personally wouldn't want that engine in my car, but i realize that's easy for me to say when it's not taking up space in my drive way.

I disagree with the members that recommend reusing the bolts. .
Sure have your own opinion and methods, I see no issue there. but i might qualify how it's presented - there's not much to disagree about - if one wants to know they can just google it. hardly any need to try to recap it all here at one time. this has been debated for decades and is well documented by Subaru design engineers through the FSM. Subaru says reuse them as do most Subaru specialiasts doing tons of these over the decades and there are very specific materials reasons they're reused, it's not just a guess or risk. There's not much to question - there's no scientific, quantitative, design, materials, reason to replace them.

I think it hard to imagine Fel Pro, or aftermarket having superior metallurgy, manufacturing, or quality control, over OEM. That said - Fel Pro may use OEM supplier to supply that part, in which case you're replacing the same exact part you're throwing away, but you do avoid the time cleaning it which is nice on dirty ones!

This isn't you of course, but this is my hesitation presenting this in an unqualified format publically.
I've seen people have failures after replacing the bolts. I don't necessarily think the bolts caused those issues - but I do think the general approach that lends the average noob/inexperienced person to choose to replace bolts when it's not necessary is more likely to incur issues.
 
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