2005 Forester 2.5 XT - 8,000 miles - M1 0W-30

[paulharmo]

Hi all - I just got my first UOA done on my FXT. I'm a bit concerned about the wear metals (Iron, particularly), and the fuel content. I plan on running my OCI much less aggressively next time - 5-6,000 miles - and I have switched to M1 0W-40. Any ideas on where the iron would be coming from in an EJ255? Aluminum could be fairly common piston slap, and although I did not warm the engine up before taking the sample, that seems like a lot of fuel!

 

[Bandito440]

You've definitely got a fuel issue to address. The virgin cSt viscosity of that oil is 10.9 @ 100C. It's dropped significantly. The flashpoint is also way down from the virgin 426F.

The 0w-40 is a better oil for this turbo motor, but you should figure out where all the fuel is coming from before doing anything else. Diluted oil is causing the wear.

Oh, and welcome!

 

[paulharmo]

Thanks!

One of the sources of fuel may well be tuning - I've got a Cobb Stage 1 tune on the car at the moment. Cobb's off-the-shelf tunes are known to be pig-rich, so I'm sure that doesn't help.

Also, although there are lots of highway miles on this OCI (almost weekly trips home from college at 200 miles each way), there's lots of cold idling time on it as well, thanks to my dislike of cold leather and remote start.

Since I've only done 500mi on the current oil, I may pull the tune off altogether and see if that makes a significant difference. It only adds a few horsepower at stage 1, and it's just a stepping stone to a downpipe and STi turbo setup.

 

[Bandito440]

Long highway trips should heat things up enough to burn off fuel and moisture. I don't know anything about the tune, but going back to stock and getting another UOA at 3,000 miles would be a good way to start isolating the issue. You may be looking at injector problems if it isn't that tune causing the fuel dilution.

Off topic, the M1 0w-40 formula is also a more appropriate choice for your Mini.

 

[paulharmo]

I'll be switching to 0W-40 once it comes out of hibernation for the winter and track season heats up. I tend to do very short OCIs over the track season - I'll only run 1-2 track events on an oil change, which can come out to less than 1000 miles.

 

[901Memphis]

A rich tuned vehicle with this much fuel in the oil will need to be drastically shortened to keep your wear down.

 

[AndrewD]

Aftermarket tuning
Severe conditions (extreme weather, extended idling)
Turbocharged
high mileage

All reasons I would shorten the change intervals, even with a good oil like M1

 

[Petersubaru]

Doesn't your manual say to change the oil more often..

 

[paulharmo]

Originally Posted By: Petersubaru
Doesn't your manual say to change the oil more often..


Yes, there should be no beating around the bush on my part, the OCI was too long. I planned to change it at 5,000 miles, but laziness and the cold got the better of me. My next OCI will be considerably shorter.

 

[Bandito440]

I think you'll be fine once you address the fuel issue, which is at a pretty severe level. It brought the viscosity to below that of Mobil's 0w-20. Most owners of these turbo motors seem to prefer 40wt oils, and the mass of analysis reports with Rotella T6 seem to suggest that's the way to go.

You'll need to be running very short OCIs if you want to keep things in check with your current setup. 5,000 miles may even be too great depending on the amount of fuel dilution and wear you're willing to accept.

Short intervals of Rotella T Triple 15w-40 would be fine too, at least during the warmer months if you're looking to save a few dollars.

 

[cptbarkey]

way too high of an OCI for that turbocharged engine.

 

[901Memphis]

Consider wear check or another lab that actually measures fuel since Blackstone only goes by Flashpoint.

 

[bluesubie]

I'm running a Cobb Stage I OTS as well and my fuel has never been that high. Keep in mind the OCI for your car is only 3,750 miles and you more than doubled it on a modified engine.

With all the info about not running Resource Conserving oils in Subaru turbos on various forums, I'm surprised you ran this oil for so long. If you still have all of your AVCS and turbo oil line banjo bolt screens, I wouldn't run ANY oil past 6,000 miles no matter what anyone tells you.

In UOA's from my wife's '99 Outback, which had piston slap that sounded like an old diesel, uoa wear was always normal. I don't think the Al or Fe is from piston slap. Definitely stick with the 0W-40. Hopefully you don't have a serious problem.

I would highly recommend a protune (not an e-tune) before hitting the track.

-Dennis

 

[paulharmo]

Thanks for the direct comparisons, bluesubie. I hadn't seen any posts against RC oils, but now that I'm aware I'll be sticking with 0W-40. I never planned to run anywhere near 8,000 miles, and hopefully my laziness won't cost me a shortblock. I'm positive that my AVCS screens have been taken out.

The Forester might enter the paddock as a support vehicle, but it definitely won't be seeing any track time - The MINI is faster in every aspect on a road course.

 

[edyvw]

I also wanted to say that for turbo application, Euro/spec oils are much better.
If you do not want to go way thicker, consider Catsrol 0W30. I would go with that before M1 0W40 for you application.

 

[Thermo1223]

It is not the 0w30 it is the fuel dilution. Extended idling will do that, it did on my 2009. The M1 AFE 0w30 IMO made my 2005 feel the best but I didn't go past 5k miles. As much as people tout T6 I think M10w40 would serve you better. It is the current fill on my '09 which is actually past due for a change because of the weather.

I stopped using Cobb OTS tunes because of the pig rich A/F. My 2009 would bog off the line sometimes. Get it protuned or just don't as Bluesubie said.

Let me piece together the UOA's in excel and get back to this.