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axgutt

Synthetic Oil Recommendation - 14 Forester - Need a Pallet

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We just bought a 2014 Forester with about 93,000 miles. It burns oil like crazy! We knew some of this going in (prior owner gave us all the records and showed me the 2 quarts he carried in the back), and I'm debating whether it's worth it to have the dealer do the consumption test and potentially replace the short block.

If we elect to keep just putting in oil (i.e. about a quart every 800 - 1000 miles or so), I wanted to get a recommendation for what type to use. I know it should be 0w20 full synthetic, but there is quite a variety of price points at WalMart. I was surprised at how many variations of Mobil 1 there were, and it seems like all the companies are making 0w20 full synthetics now. This car will be driven about 15,000 miles a year, so it's not a huge amount of money either way, but I'm sure I can come up with something to do with the money.

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Since it goes through that much anyway I would just get whatever is on sale. As long as you stick with the 0W-20 Synth like is recommended you should be fine. I'm sure you will get a dozen different opinions on this, that is mine :)

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If it is using oil like crazy I would up the weight. At least a 10w30 but myself I would use the 0w40, being it is going thru that much oil. 

 

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Upping the weight could throw a code for the active valve system.. If it's using that much oil it will fail their test and you'll get a new short block. The warranty on that only covers to 100k so best to get it now while you can

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10w40 would be just fine. Even 15w50 would be fine. 

The 0w20 spec is for fuel economy. The clearances in the engine don't change AT ALL on a 0w20 vs a 10w30 engine. They change the oil recommendation based on fuel economy, and film strength depending on engine load (turbo vs non, etc). 

We run the same clearances in engines making 600+ HP on high boost. We just run them with 15w50 Dominator race oil instead of 10w30 because we need the film strength. 

Honestly we rarely run anything lower than a 5w40 because Subaru engines blow out their main bearing tolerance within a few tens of thousands. I tore down a 24k WRX engine (no modifications) and the main bearing clearances were already out of spec. 

Changing the weight will NOT throw any codes. We routinely run 40 and 50 weight oils in engines with AVCS, dual AVCS, and AVLS. Never had one throw a code from it. That's BS. The engine doesn't even have an oil temp sensor. And the duty solenoids use feedback from the cam position sensors, etc to adjust the duty signals. They do not rely on anything as crude as oil viscosity. Which often drops as the oil sheers from use when considering synthetics. 

GD

Edited by GeneralDisorder
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8 hours ago, GeneralDisorder said:

10w40 would be just fine. Even 15w50 would be fine. 

The 0w20 spec is for fuel economy. The clearances in the engine don't change AT ALL on a 0w20 vs a 10w30 engine. They change the oil recommendation based on fuel economy, and film strength depending on engine load (turbo vs non, etc). 

We run the same clearances in engines making 600+ HP on high boost. We just run them with 15w50 Dominator race oil instead of 10w30 because we need the film strength. 

Honestly we rarely run anything lower than a 5w40 because Subaru engines blow out their main bearing tolerance within a few tens of thousands. I tore down a 24k WRX engine (no modifications) and the main bearing clearances were already out of spec. 

Changing the weight will NOT throw any codes. We routinely run 40 and 50 weight oils in engines with AVCS, dual AVCS, and AVLS. Never had one throw a code from it. That's BS. The engine doesn't even have an oil temp sensor. And the duty solenoids use feedback from the cam position sensors, etc to adjust the duty signals. They do not rely on anything as crude as oil viscosity. Which often drops as the oil sheers from use when considering synthetics. 

GD

Gosh, this is starting to feel like NASIOC with all this talk of oils and bearing clearances.  Is that Uncle Scotty I hear?  d00000000000000000d!!!!! 

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Well I don't know about any of that NASIOC stuff, but I can tell you from building engines, breaking engines, and running them on my dyno - plus hundreds of hours of research, discussion with respected engine builders, Amsoil's technical department, etc that oil viscosity isn't going to make any serious differences in the way the engine will run - you use light oil for light loads and MPG. You use heavy oil for heavy loads and take the MPG hit. Anything between an SAE 20 and an SAE 60 is going to run more or less the same - it will have some mild effects on oil pressure and temperature but for daily driving under light loads anything in that range will adequately lubricate the engine.

Anyone that is obsessed with oil viscosity in their ho-hum daily driver factory engine is only doing so because of a lack of fundamental understanding. If they understood oil and engine clearances the way an engine builder does they wouldn't be concerned in the least. 

It just doesn't matter. I run all my engines hard - factory or not. So I don't run anything less than a 40 in my cars. Ever. Regardless of "manufacturer recommendations"

GD

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15 hours ago, axgutt said:

 potentially replace the short block.

If we elect to keep just putting in oil

why would you not look into a test and possible free OEM shortblock?  there's not only the  current oil consumption - but the possibility the previous owner ran it too low on oil, the converter life will be shortened and be posing you future codes/issue, and you'll have a seized engine/thrown rods in the future and the consumptions could increase considering you're presumably going to have this thing awhile if you just bought it. 

otherwise - what GD said - use much thicker oil.

Edited by idosubaru

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We're bringing it in for the oil consumption test next week, as well has to have them check out a couple of things. Part of what I wondering is if they'll honor the warranty since we bought it used. Most of the subie's I've bought have had 120,000 or more when I bought them. The only warranty repair I've had done was a frayed seat belt at 392,000 miles on one of my '95 Legacies. Apparently the seat belts are treated differently. 

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1 hour ago, axgutt said:

We're bringing it in for the oil consumption test next week, as well has to have them check out a couple of things. Part of what I wondering is if they'll honor the warranty since we bought it used. Most of the subie's I've bought have had 120,000 or more when I bought them. The only warranty repair I've had done was a frayed seat belt at 392,000 miles on one of my '95 Legacies. Apparently the seat belts are treated differently. 

The extended warranty for oil consumption is 8 years/100k miles

https://subaru.oemdtc.com/80/engine-oil-consumption-2013-2015-subaru

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I'm happy to report that we failed the oil consumption test! About 700 miles after they did the oil change the oil light came on. A new short block is on the way to be replaced under warranty.

We're going to get the clutch done as well while the engine is out, which is going to save a bunch on labor. Anything else that I should have them do while they have everything apart?

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pay for new hoses and belts. New spark plugs if it's not in their repair list with the shortblock. Your getting basically free labor on the clutch

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clutch and throw out bearing for certain based on access/labor costs. 

plugs and valve cover gaskets make sense.  They're a couple hundred in labor. 

These are not all that advantageous due to the engine work but I'd also do the hoses, PCV valve, air filter, and serpentine belt - but you're not really saving much labor to do those now, It would just make a really easy 100,000 miles moving forward. 

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5 minutes ago, idosubaru said:

clutch and throw out bearing for certain based on access/labor costs. 

plugs and valve cover gaskets make sense.  They're a couple hundred in labor. 

These are not all that advantageous due to the engine work but I'd also do the hoses, PCV valve, air filter, and serpentine belt - but you're not really saving much labor to do those now, It would just make a really easy 100,000 miles moving forward. 

The valve cover gaskets are getting replaced anyway. Short block swap.....

Pretty sure the short block warranty job includes a new PCV valve.

All the other stuff will be zero labor so might as well. Plugs and serp belt, etc. 

I would do new radiator hoses as well. 

GD

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Not sure if mentioned but you may want to do the timing belt now since it will only essentially be the parts cost.  Make sure they replace the idlers and tensioner as well as the timing belt.

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8 hours ago, Mike104 said:

Not sure if mentioned but you may want to do the timing belt now since it will only essentially be the parts cost.  Make sure they replace the idlers and tensioner as well as the timing belt.

FB engine. No timing belt.

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