Subaru WRX - What mileage to do oil analysis

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carb850

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I have an '04 WRX and thinking about getting an oil analysis. I found on a Subaru specific forum a fair number of guys spinning bearings at ~ 60K. A good number of them were using Mobil 1 5W-30. I used dino oil until 10K, that is when I switched to Mobil synthetic. I ran that up until 35K and then switched to Royal Purple. After spending a fair amount of time on this site, I switched to GC at 42K.

Last few changes I have done about 7K OCI. I feel pretty safe with that but these spun bearing stories have me worried. Reading up a little on the UOA it seems they can measure if your getting bearing wear, right?

Anyhow, how many miles should I put on this oil change before doing a UOA?

Thanks
 
The more miles the more data. But of course that can be taken too far. I don't know anything about Subarus bearing issue, but I would shoot for minimum 6k on your OCI (7 would be peaches).

UOAs are typically used to discern wear on various engine internals, but I'll let someone else chime in on whether the Subies bearing metal can be isolated on the UOA report (ie, if it's a distinct metal from other moving engine parts).
 
I would perform one every 10,000 miles on the WRX (like I will be doing on my 2.5i) to check for wear patterns. That's $20 a year for peace of mind
smile.gif


For the UOA, try for 5000 miles at a minimum if you're doing long drains, or whenever you drain it. The UOA will be specific to your car and your driving only.
 
Hey Carb,

I have an '02 WRX approaching 80,000 miles and I was thinking about getting a UOA when I reach my next OCI as well. I actually already received my kit from Blackstone so I guess I did a little more than think about it. I'm only about half way through my current OCI so I'm at least a month away. I've been running M1 5W-30 for the past 30,000 miles or so with OCIs in the 3,500 mile range. Based on what I've learned from BITOG (I'm still a newbie) I could be wasting my money. No spun bearings for me at least. I do have a bit of the cold engine piston slap noise which both dealers I visited said is normal. Anyway, when I get my results, I will post on the site.
 
Quote:

... a fair number of guys spinning bearings at ~ 60K. A good number of them were using Mobil 1 5W-30.

Click to expand...
I don't claim to know much about oil, but I do know a little bit about logic and causation. There's an awful lot of superstition, mythology and illogical conclusions that float around on NAISOC as well as here.

Mobil1 5w30 is probably the most widely used oil for WRX owners. So it makes sense that if there are any problems with the car, many would be with cars that use this oil. Many of those cars with spun bearings also have RE92 tires but that doesn't mean the tires caused the problem.

I've never seen anything remotely close to a statistically meaningful study to indicate the Mobil1 really causes the problem.
 
I've run GC and Motul 8100 5W30 for 6 - 7,500 miles and my wear is normal (2.5L turbo). For a first UOA, I wouldn't go past 5,000 miles like Dominic said.

Yes, there are a fair number of spun bearings in the 2.0L forum on nasioc it's probably a combination of things, IMO. Fuel quality and/or state of tune leading to detonation, wrong oil for the conditions, etc. One guy just posted that he uses M1 5W30 in the desert! People just don't bother to read the manual.

OTOH, there is a guy here (and nasioc) that has run M1 5W30 for 7,500+ miles and has great UOA results. A subie tech on subaruforester.org said he saw a spun bearing on a stock WRX using M1 5W30 and the car is owned by a "conservative couple" in their mid-40's. I guess he through that in to say it's not just kids with highly modified WRX's.
smile.gif


Bearing wear in Subaru's will show up as high aluminum for one. I would only use a ACEA A3 and/or a 5W40 oil in a hard driven WRX. 5W30 is preferred for fuel economy.

-Dennis
popcorn.gif
 
Quote:

I would only use a ACEA A3 and/or a 5W40 oil in a hard driven WRX.

Click to expand...


+1. I'm not familiar with the Subies (though my first two cars were a DL and a GL back in the late 70s & early 80s - and I want a Subie real bad but that's a personal issue) - anyway, very good recommendation for an A3 oil given your issue.
 
Quote:

Quote:

... a fair number of guys spinning bearings at ~ 60K. A good number of them were using Mobil 1 5W-30.

Click to expand...
I don't claim to know much about oil, but I do know a little bit about logic and causation. There's an awful lot of superstition, mythology and illogical conclusions that float around on NAISOC as well as here.

Mobil1 5w30 is probably the most widely used oil for WRX owners. So it makes sense that if there are any problems with the car, many would be with cars that use this oil. Many of those cars with spun bearings also have RE92 tires but that doesn't mean the tires caused the problem.

I've never seen anything remotely close to a statistically meaningful study to indicate the Mobil1 really causes the problem.

Click to expand...



Your absolutely right. While I'm not defending NASIOC at all, I will say a few have pointed out exactly what your stating. A few have even posted about having the same issue using other oil. So I'm not convinced that it is the fault of M1, but I seen enough to have me switch brands. Plus many quote that M1 shears to nearly 20W pretty quickly.
 
Quote:

Huh...never heard of any Subie engines having any problems...I too would worry about bearings if other WRX owners have had this problem...How long is the Subaru warranty?

Click to expand...


5Y 60K miles but they are very quick to deny warranties for any modifications to the car. Currently I have only remapped the ECU which could be reversed easily but I still don't put it past them to deny warranty. Plus, the spun bearings seem to be happening between 50-70K miles. I could see mine going at 61k
wink.gif
 
Quote:

I've run GC and Motul 8100 5W30 for 6 - 7,500 miles and my wear is normal (2.5L turbo). For a first UOA, I wouldn't go past 5,000 miles like Dominic said.

Yes, there are a fair number of spun bearings in the 2.0L forum on nasioc it's probably a combination of things, IMO. Fuel quality and/or state of tune leading to detonation, wrong oil for the conditions, etc. One guy just posted that he uses M1 5W30 in the desert! People just don't bother to read the manual.

OTOH, there is a guy here (and nasioc) that has run M1 5W30 for 7,500+ miles and has great UOA results. A subie tech on subaruforester.org said he saw a spun bearing on a stock WRX using M1 5W30 and the car is owned by a "conservative couple" in their mid-40's. I guess he through that in to say it's not just kids with highly modified WRX's.
smile.gif


Bearing wear in Subaru's will show up as high aluminum for one. I would only use a ACEA A3 and/or a 5W40 oil in a hard driven WRX. 5W30 is preferred for fuel economy.

-Dennis
popcorn.gif


Click to expand...


I hate to sound ignorant, but what is ACEA A3? I switched to GC which the guys on this site claim is very close to a 40W.

BTW, GC better be my answer because I stocked up on 27quarts while I found it on sale for $4.49
laugh.gif
 
M1 10w30 is a light 30wt (visc=10.0 at 100deg) - so folks may be reading something into it.

If I were a Subie owner (and I wish I was) in a Subie with known wear metal issues, I'd leave the M1 regular line (wouldn't wait around for conclusive evidence on it's wear metal connection). There are M1 lines that are A3, so it's not like you'd have to leave M1 altogether.
 
A tribologist will follow my post and make me look foolish (hate being exposed) - but A3 means it has a HTHS rating above 3.5 (High Temp / High Stress) - this refers (perhaps among other things) to the oils ability to resist being completely "squished" out from between two compressing surfaces. So in our bearing issue, a non-A3 could be getting squeezed out to the pt that there is no lubricant between those bearing. A3s meanwhile can better stand their ground when the pressures on.
 
Quote:

Conservative couples should have their WRX reposessed.

Click to expand...


Que? I'm conservative and proud of it. When I purchased the WRX back in 04 I knew of the weak tranny. I wasn't happy about it but I went into it with eye's wide open. At the time though, I thought the engines were stout and not a source of problems. This spun bearing issue on non racing cars has me concerned. So guilty as charge on being a conservative but they cannot repossess as it is paid for
wink.gif
 
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