OIL USE IN 2012 IMPREZA

[The Dude]

A strange problem with our 2014 MT Impreza with 30,000 miles on the clock. This car burns excessive amounts of motor oil when it is driven for long periods of times at highway speeds (65-70 MPH). Our Impreza used  more than 1 quart of oil during a recent 650 mile drive to Miami, FL. When the car is driven around town at 35-45 mph, it uses considerably less oil. Any thoughts on this? Thanks. 

[Fairtax4me]

This seems to be a common thing with the new engines. Lots of threads about this on the various forums, but I haven't seen any conclusive reason for it.

 

What kind of oil do you run in it?

[cavygirl]

My 2012 Impreza has only been using only the 0-20W recommended in the owner's manual, and oil consumption has been erratic since the day I drove it off the lot. It's getting worse at 45K on the odometer. A call to Subaru yielded the opinion that using a quart of oil every 1200 miles is "normal". Funny, I've never owned a car that even used a quart between changes before. After expressing my displeasure to Corporate, their response seems to be a flurry of emails letting me know my guaranteed trade-in value!

 

The local dealer, of course, agrees with Subaru on the oil consumption. The dealer solution: have me drop by their inconveniently located shop every 1200 miles to have them check the oil. My usage in around-town driving is within these "normal" parameters, so this won't help me. Any time the car runs at high speed for 4 hours or more, it pretty much sucks a quart, but it's usually when I'm nowhere near an open Subaru dealership.

 

I'm concerned that this constant use of oil will cause some sort of disastrous repair bill after the car passes the drive train warranty. Sooo. . . . .I'm ready to dump this turkey, my second Impreza. My previous 2009 must have been dropped too hard onto the dock when it was off-loaded from the ship from Japan. All sorts of things were never right with that car, from sun visors that wouldn't stay where you put them, to the rattling exhaust system that could never be quieted, to, the last straw, the fan eating a hole in the radiator at 44K miles. The antifreeze is a pretty blue, but not sprayed all over the engine.

 

Am I just unlucky or is Subaru's sterling reputation undeserved?

[ccrinc]

1) Replace your PCV valve.  It's a very common failure and results in oil use as bad as 1 qt. in 300 miles.

2) The oil journals in the rod and main bearings of these engines are very narrow.  Even more so than the previous "generation" of these cars. 

 

Are either of these cars turbos? Not all Imprezas are, so I'm wondering. (?)

[nipper]

A Qt every 1200 miles is acceptable, but not normal. The problem is the zero weight oil. I am waiting for this to start buying a mfg in the ail with engine failures. It is a very thin oil and is working past either the valve seals or rings. Some oil is used on some engines to cool the piston skirts and gets vaporized, but this consumption seems to be across the board. I would suggest a different brand of oil or go to a slightly heavier weight and see if that helps. The 0-20 is just for MPG gains.

 

https://www.cars.com/articles/2013/08/expensive-oil-changes-are-here-to-stay/

[Subasaurus]

my gf's civic takes 0w-20, remember 2 years ago when i saw this i was like whaaaa?? thats pretty much water, wheres the lubrication, not suprised theres issues comming up now about this weight in oil.

Edited April 28, 2015 by Subasaurus

[ccrinc]

5W20 is much better for the car.  My FSM says that's what they come out of the factory with, as do several of my contacts at dealerships across the country.

[1 Lucky Texan]

5W20 is much better for the car.  My FSM says that's what they come out of the factory with, as do several of my contacts at dealerships across the country.

I always wonder what the manuals recommend for the same engine in Europe and Asia?

 

does thinner oil have anything to do with the 'lamb chop' rods? (have those been robust so far?)

 

 

 

[ccrinc]

I always wonder what the manuals recommend for the same engine in Europe and Asia?

 

does thinner oil have anything to do with the 'lamb chop' rods? (have those been robust so far?)

 

 

 

The new style of rods is to achieve more "throw" in some of the newer engines without making the engine larger or increasing the bore.  More "throw" = more horsepower.  The crank is also different.

These are a b*%#h to build because the pistons and wrist pins are inaccessible until AFTER the block is split.  Therefore, the pistons must be attached to the rods before closing the block as well.

 

Here's a link to the article from which those rod pics came.  http://www.caranddriver.com/news/subaru-fb-series-engine-subaru-flat-four-engines

[nipper]

I'm going to ask on the Offroad board, which is Mostly Austrailian and see what they have heard. So far they found some odd towing limits ofr the Diesel and CVT combination.

[nipper]

I hate to get on the lawsuit band wagon, but http://www.torquenews.com/1084/why-subaru-s-excessive-oil-consumption-issue-could-spoil-their-party

[Rooster2]

I am old school, so don't like the idea of using 0-20 weight oil. Seems more like water, as someone else responded. With such low viscosity, no wonder the piston rings don't wipe much oil off the cylinder walls, which allows it to get burned in the combustion chamber. Agree that the  0-20 weight oil is used for a little better miles per gallon of gas, not for better lubrication.

 

Suggest you use 5w-20, or 10w-30 weight oil. Can't imagine that the narrower oil passages will have any trouble with a tiny bit thicker oil.

 

In my old Outback, I use 20-50w in the summer time with no problems.

[1 Lucky Texan]

Here's a link to the article from which those rod pics came.  http://www.caranddriver.com/news/subaru-fb-series-engine-subaru-flat-four-engines

huh - found this in that article - wonder if they're regretting it now?

 

******"Subaru claims a 28-percent reduction in friction losses within the engine, with the biggest contributors being lighter pistons and connecting rods, as well as a drop in piston-ring tension. "******

Edited April 28, 2015 by 1 Lucky Texan

[nipper]

ooo i didnt see that. And all the mfgs are having some issues. 

[Fairtax4me]

The problem isn't entirely due to the weight of the oil, but also because its a synthetic oil. Synthetics work in roughly an opposite manner of a conventional "Dino" oil. Synthetics are based on a high viscosity oil, and have additives that allow them to "act" thin.

Dino oils have a low viscosity base and have viscosity improvers that cause them to thicken as the oil heats up. When Dino oils are new, and the viscosity improvers are fresh, a 5w20 oil can become almost as thick as a 5w30 when at operating temperature. The viscosity improvers break down with use, and the oil appears to "thin" as it ages, but the base oil actually thickens as it breaks down. We don't typically physically see this with gasoline engine oils because of things like fuel dilution and water contamination, plus we usually drain oil when its warm, to speed up the drain process and make sure any solids in the oil are suspended rather than settled on the bottom of the pan. This means with a 5w-20 conventional oil you will start to see accelerated oil loss as the oil ages. Once past that 3,000 mile change interval, it'll go from a 1/2 quart loss to a 1 quart or more of loss in a shorter time period as the VIs break down and the oil becomes thinner at operating temperature.

 

Synthetic does the same thing, the base oil will thicken as it ages, but the additives in synthetic break down at a slower rate, which means better stability over time. If you were to age a 0-20 synthetic oil in a controlled manner, the base oil will eventually thicken to be a 25 or 30 weight oil, but the additives in the oil still allow it to flow much easier than a Dino oil. It's because of the additives that give synthetic oil its fluidity that it can flow past the piston rings much easier to be burned in the combustion chamber, but it is also vaporized easier by piston ring blow-by (compression that is forced past the rings), and is carried out by the PCV system.

If we remove the additives that make synthetic thin, its cold flow properties and stability (the two main reaons for using synthetic) go out the window, and you basically end up with a straight 20 weight non-detergent oil. Though it's more highly refined (fewer impurities) than a typical conventional oil.

 

The best option is really to switch to a conventional oil, but you can't go too thick, because the cold flow properties ofa conventional will cause accelerated wear on cold startup. A. 5w-20 or 5w-30 conventional will work fine. The higher the first number, the thicker it is at cold startup, and you begin to run into issues with poor lubrication due to insufficient oil flow. A 20w-50 for example, will be too thick, even in the summer, to provide proper lubrication until the engine is almost to operating temperature.

 

 

 

Emily, do the newer rods allow enough access to torque the bearing caps with the block halves already assembled?

[1 Lucky Texan]

yeah, I'd like to see a video or step-by-step of how an FB engine is assembled.

[nipper]

[1 Lucky Texan]

cool!

[ccrinc]

I wish we had equipment like that in our shop!

On the other hand, REbuilding an engine is not like building a brand new engine.  All kinds of measurements must be made to assure that the tolerances closely match what comes out of the factory.  Factory-new, everything is pre-measured and pre-set to be perfect.  After being run, abused, overheated, etc., getting back to those tolerances (or as close as can be) is a one by one process, not assembly line.  Every head, every block, every valve, crank, connecting rod, etc. all has to be measured and machined to get back to as close to perfect as possible. 

 

Fairtax: the torqueing is done with the case partly open, before it's sealed.  It's touchy and it's close.

[ccrinc]

I hate to get on the lawsuit band wagon, but http://www.torquenews.com/1084/why-subaru-s-excessive-oil-consumption-issue-could-spoil-their-party

 

Ouch.

[ferret]

Subaru released a TSB for the 2012/2013 Impreza. Here's a link to the XV board:

http://www.subaruxvforum.com/forum/problems-maintenance-warranty/4794-xv-high-oil-consumption-2.html#post164274

 

Also I would warn against using convential oil as the passages for the cam advance timing are miniscule at best and this is another reason to use, as I put it, "synthetic water " ..... oil viscosity 0 as in 0-20. Using thicker oil causes CEL's related to intake cam timing.

Edited April 29, 2015 by ferret

[nipper]

Thats has loopholes big enough to drive a truck through, and doesnt specify what the fix is.

[Fairtax4me]

I want one of those dyno machines! 

 

 

 

Fairtax: the torqueing is done with the case partly open, before it's sealed.  It's touchy and it's close.

Sounds like my kinda engine build! Backyard style! I'm sure your shop is much cleaner and more organized than my shed though! 

It looks like there should be enough room to do it with the case assembled but that tool they used in that video reaches in there pretty far. Hard to get a good torque when you use a 12" extension to reach the bolt. 

[alfish]

I signed on to this website to get a real answer to a real problem. I am sorry to vent a bit, but this is an easy one. Subaru lost a class action suit and had to give an extended warranty to the 2012 (possibly other models) Impreza for cars with excessive oil use. Go to your dealer and have them do the work to fix your oil burning problem. mine doesn't have that problem but I got a letter in the mail, unsolicited, years ago - from Subaru!

 

My problem is a strong gas smell ESPECIALLY strong when starting the car. I brought it to the dealer and left it 3 days. They couldn't even smell gas. COME ON!!!! It stinks gas!, Called Subaru Corp and they just tell me to bring it back to dealer. Man, I left it there for three days and they couldn't even smell anything. Their "mechanics". Have to have something wrong with their nostrils not to smell something! I need a real answer! this has been happening since the car had 40k miles! It now has 88k and I am fed up!

[idosubaru]

Just looking at the little information we have: you don't mention fuel on the ground or poor gas mileage (symptoms of appreciable leaks) and you've been comfortable waiting 40,000 miles. Makes its not too alarming they haven't found it?

 

There are electronic devices (gas analyzers) that can sense hydrocarbons. I think they're used for emissions, exhaust and headgasket monitoring. some shops have them and would be definitive diagnosis that there is excessive gas.

 

Cars have a lot of smell and people vary absolutely wildly in their perception and abilitly to sense or tolerate smell and sounds. smell is very foggy and blurry to me....if I smell something at all. I probably wouldn't notice it over nominal automotive smells either at a dealer parking lot where the nominal smells aren't that of a rural homestead to begin with.