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Kamen 12-19-2012 09:32 PM

Interpreting the results of engine-oil analysis
1 Attachment(s)
I'm not sure if this is the right forum, but I wasn't able to identify a more appropriate one. I also apologize for not introducing myself first in the proper forum, but this technical post will serve as a pretty good introduction as that's who I am. All right, maybe a quick introduction is in order.

I have owned and maintained myself multiple Subarus since 1999, and I still have them all, including a 300,000-mile Legacy. It just won't die. But I am looking to replace it and this is the reason for this post.

I am looking at several vehicles, one of them a 2008 outback XT with 66K miles on it. The owner hasn't been very diligent with its maintenance and might have lapsed on oil changes a couple of times (possibly, up to 10,000 miles in between oil changes). I have visually inspected the car as much as I can and there is nothing remarkable: no fluid leaks (other than a small grease leak at the end of the outer passenger-side CV-joint boot), no excessive corrosion for the mileage, although all surfaces appear damaged by the magnesium chloride used for deicing here. The windshield is cracked, that'll have to be replaced, the main accessory belt has missing ribs, that's easy. The driver-side bulb is out and one of the license plate bulbs is also out. I measured the battery voltage at idle: 14.2 V (a little high?) The driver-side wheel well seems to be a about 0.5" lower, there's a small grind at one of the wheels (bent backing plate?) - nothing much to worry about.

But the big thing I'm worried about is the missed oil changes, given the infamous turbo failures. So I decided to get the engine oil analysed. The conclusion at the lab was that all is good, but I haven't gotten any detailed explanation for the individual results. I've attached the report here, in case someone can provide some insight into it.

Overall, I like the car but I think I could get a cleaner car if I keep looking. Not sure what to do.


Whatisit 12-20-2012 12:36 AM

turbo subaru, and missed oil changes/ ran on low oil = turn in the other direction and run. If you insist on buying it, have money put aside for a new engine and turbo. that is all i can suggest. These newer 2.5's are much more fragile then the older ej 2.2's

pilot378 12-20-2012 10:09 AM

I'm with Whatisit on this one. Even if the oil doesn't show any problems now, an OCI of that long can't be good for a turbo, especially with the problems already associated with these turbos. Car might be fine now, but as poorly maintained as it was, the life of that turbo will most likely be cut short. Could end up being fine for years, but I wouldn't chance it. Take your time, find a car with low miles that's been taken care of, and the extra time you take will hopefully pay off with a reliable, fun to drive car. :)

GTPpilot 12-20-2012 10:20 AM

I'm not seeing anything too scary on that report. Silicon might be a little high.
That would usually be from something getting by the air filter but in this case
probably due to alot of miles on the oil.

See for more oil info than you ever wanted to know.
Referred to as BITOG by oil geeks.

Dbl_D718 12-20-2012 02:02 PM

^ Agreed. Not saying you shouldn't worry about the supposed long oil change intervals, but at least the metal content on that report is nice and low which indicates no excessive wear to bearings and such.

The bigger numbers (calcium, magnesium, phosphorus, zinc) are typical oil additives and are expected to be higher in concentration.

HAMMER DOWN 12-20-2012 03:50 PM


Originally Posted by Kamen (Post 4212674)

I am looking at several vehicles, one of them a 2008 outback XT with 66K miles on it. The owner hasn't been very diligent with its maintenance and might have lapsed on oil changes a couple of times (possibly, up to 10,000 miles in between oil changes).


Extended OCI will not harm any thing. As long they used the right oil & filter to protect for the OCI they used. And keep the oil top-offed.

I have almost 210k on the original VF-40 turbo & motor. Stage 2+ 18.5 psi of boost. My Avg. OCI is 15k. Compression test at 174k, was 145,147 145,150psi.

Oil history from day1:

New. SOA filter & oil 4000 miles
1st. oil & filter change till 30k, Mobil1, 5w-30 every 6000 miles \ Fram oil
filter every 3000 miles.
Amsoil 0w-30 SSO and Amsoil Ea oil filter, Ea15k13 oil filter at 30k-73k .
At 73K, my filtration I use. My oil system now is 7qt. I add 2-4qts over the 15k OCI.
Oil consummation hasn't change sense car was new.
Most off the shelf oil filter, filter down between 20 & 40 microns. Amsoil full-flow oil filter is 15 microns & Amsoil By-Pass oil filter is 2 microns.
This filtration system add 2qts. of oil to you motor. Which help keep the oil cooler.

My GT mileage; over 209k +, will be over 210k by the weekend.

My G\F's 05 WRX use same oil & OCI, but uses 1 single spin-on, Ea15k13 oil filter. The WRX as over 150k. I add 2-4qts over the 15k OCI.
Oil consummation hasn't change sense car was new.
My 07 Pontiac Solstice GXP, 2.0L DI turbo charge motor, Same oil & OCI, but No Ea filter is available. I use a WIX filter. Change oil filter only every 5k. GXP as over 84k. No oil consummation over it's 15k OCI.

In short, check you oil level often & top as needed. Use oil & filter that will protect for the OCI your running. OA's is the only way you know that your oil & filter is up for the challenge. After that IMO no OA's are needed.

But if have any doubts, walk away.

pilot378 12-20-2012 05:31 PM

Wow, Mike, that really is impressive. No doubt, an engine and turbo can last a long time with a high OCI (as you've proven with two cars).

If you've owned the car for years, use a high OCI and check it with an OA, then, again as you've proven, you could be totally fine. But from what I've read on the forums and heard from my mechanics is that the longer your OCI, the higher chance you could run into turbo problems. Now from what I've seen over the past few years in Subarus and beyond, looking at a turbo car with a high OCI is sometimes paired with a car that hasn't been cared for very well (doesn't apply to you, Mike, I'm sure you treat your car great. From the pics I've seen, it's in great shape). From what the OP says, the car doesn't seem too bad off, and has relatively low milage. So it could be in perfect mechanical condition, and might not give you any problems. But personally, when I'm looking at buying a used car that I don't know all too much about, I like to see religious maintenance. After all, if the previous owner slacked on the OCI, what else could they have slacked on? A car is obviously a large investment, and I just like to buy one that I know has been treated right. Of course, that doesn't stop things from breaking (just spent $800 to replace a bad bearing in the transmission...), but personally, it just offers a little peace of mind. $40 to change my oil every 3,000 or 3,500 miles with synthetic isn't that tough to do, and IMO, helps protect the car that much better (I guess we'll see how long my turbo lasts :lol:).

This is totally just my opinion, don't mean to disrespect any of you long OCI guys, cause we've seen that work well for people too. But that's my take on buying a new turbo Subaru anyways. :) I waited almost a year before I found the "right" car at a great price. I think patience can really pay off. However, Kamen, if you think you'd be getting a good deal, then go for it! Treat it well and I'm sure you'd be fine. :)


pilot378 12-20-2012 05:33 PM


Originally Posted by HAMMER DOWN (Post 4213798)
In short, check you oil level often & top as needed. Use oil & filter that will protect for the OCI your running. OA's is the only way you know that your oil & filter is up for the challenge.

And Kamen, no matter what you decide, this^ is a great way to help keep your car running well for a long time. :)

Kamen 12-20-2012 05:34 PM

Thanks, guys. You don't make it easier on me, with the contradicting suggestions. The things is, they don't make turbo wagons (Legacy or Outback) anymore so it's really hard to find a good, low-mile example, even in the Land of Subaru, where I am. I've been looking for a couple of months now and still no luck. At dealerships you don't know much of the OCI history (the CarFax rarely shows all of them) and owners don't always keep records. This particular car has records, but there are lapses - it is not certain that they skipped those oil changes, they just don't have the records. The oil that's currently in the vehicle looks like it's been there for at least 4-5K miles (what the owners thinks it is) and the level is actually a little too high, so it seems like it hasn't been consuming oil. My 155K-mile 2.0L WRX still does not consume any oil, and I used to go over 10K miles between oil changes, using Mobil 1 (when I did 10K miles in four months).

It's so hard to decide! There is now another '08 OB XT at 59K miles, with a CarFax full of oil changes but it has four 4500-5500-mile OCI and one 7300. Did they do them but were not recorded? No way to know - it's in a dealership. Will there ever be one with pristine service record?

What about those extended warranties that you can get through Subaru dealerships? Is that any good?

Why don't people spend some money and time to maintain their vehicles properly! What to do...


pilot378 12-20-2012 05:48 PM

It is tough to get a full service record. The owner I bought mine from kept receipts, luckily, but most don't do that. Even then, he may have gone long on a few, it's pretty much impossible to tell.

If your previous owner was regularly going 10,000 miles between oil changes, I'd be pretty worried, but from what you said, it seems like that wasn't the case. Not that I'm changing my mind, haha I'm still pretty picky about buying a car, but I might be overly so. If the car looks as though it's been treated well, the OA looks good (which it does), there are no big mechanical problems, and it's a good deal, then HAMMER DOWN's advice may be the way to go. Basically none of this helps your decision :lol:, I know, but it'll end up coming down to you. If you feel good about it and you maintain it well, I doubt you'd end up blowing an engine as was suggested earlier.


Originally Posted by Kamen (Post 4213923)
Why don't people spend some money and time to maintain their vehicles properly!

This^ Doesn't make sense to me haha, and I wish more people would do it. It's really not that tough to properly maintain a car...

HAMMER DOWN 12-20-2012 06:01 PM

You could have a compression & leak down test done & have the turbo pulled & check for shaft play. The results could help make up your mind. This would be on your dime. But it's pennies on the dollar, compared to a blown motor &\or turbo.


Whatisit 12-20-2012 06:22 PM

or the $$ you will spend on an aftermarket warranty, just buy a new turbo with it. i would be okay with long oci if the owner used quality synthetic. But their is always that chance that the previous owner got the $19.95 special dino oil change from walmart and drove it 8k. If you read this site you will find many stories of people having to fork out thousands of dollars on a new turbo, and engine after owning it for only a month or two.

Kamen 12-20-2012 09:43 PM

Thanks for the advice. The trouble is, the owners are not comfortable with me doing anything complex to their engine myself (I've done compression tests on my older legacy). I could arrange it with some shop, but how do I trust them to do a good job? I don't know any good ones (I've always done all of my work myself). Plus, a compression test is about engine wear, not as much turbo wear, which appears to be the concern here. They did not want me to open the exhaust without some guarantee and I can't blame them.

Here's a thought. If it's all about losing the turbo (as along as it's caught in time), then, given that a new turbo is around $1200, if I can lower the price by that much, maybe it would make sense. As long as I can figure out a way to get a warning (that my wife, who'd also be driving the car) to react immediately upon a failure. Or maybe I preemptively replace the turbo?

This just stinks! I don't like the NA 2.5L engine or the H6. And the one thing about my Subies (all 650,000 miles of them) is that they have never, never, ever left me on the road, with all the abuse I have inflicted upon them (autocross, rallycross, ice racing, etc.) This is driving me mad!


fishbone 12-21-2012 06:07 AM

Kamen you will get varying advice because perception is reality and we tend to have different experiences with these cars.
I've myself kept reading about blown this and that, you read enough and the whole car is a ticking time bomb, you should simply walk away from Subarus period.
I am not dismissing the cautious advise you were given, it is sound.
But my opinion is a long OCI will not necessarily lead to a dead turbo/engine.
It also depends what oil was used, how the car was treated, if the oil ever ran low.
These are the unknowns. An OCI is not an end all be all because from what I was told it only measures particulates in a certain range and can very well be blind to others.
If I were the average person I wouldn't be comfortable with you doing any extensive testing either. You want the car or not? :)
To me it sounds like you've been dilligent when looking at this car. Only you will have that feel if you should or not pull the trigger.
It's not the only OB out there, maybe you should keep looking?
I won't have ANY record of my maintenance when I sell this car other than my own notes in Google Calendar.
I do all my maintenance myself.
If this car wasn't used in city traffic and the lapses are not extensive in months AND the owner can account for said lapses, sounds to me like it should be OK.
I wouldn't want to buy it maybe because of the other things you listed. Windshield cracked, some damage to paint, etc.

fishbone 12-21-2012 06:10 AM

Here's one last thing.
If you have to post about a car you are considering buying on a forum, maybe you should just walk away :)

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