Mobil 1; 5W-30; 9,500 miles; Subaru Outback

[ru_bunky]

Here's an interesting for y'all to take a look at.

I've used synthetic for the last three oil changes but have used 'normal' oil at various times in the car's life.
I intend to replace the current oil this weekend to do a test after 3,000 miles.
I've noticed a trend among Subarus to have a high lead count but I'm thinking the long interval change is contributing to it.
No oil was added between changes.
Comments welcome.
Russell

 

[LubeOiler]

I am beginning to wonder all of a sudden about this high lead readings of late.The statement: the use of leaded oil additives would be what exactly.Is it the gas or is there something being added to our cars engine in the synthetic oil thats caused this.We used to rarely have these kind of posts where the lead shoots up like this.Have the testing companys gotten together to give us something to worry about.

Perhaps the extended OCI has something to do with it but the additive route seems the most likely reason. Here is another current OCI that has given us a reason to be concerned. I started running mobil 1 at my second oil change around 6,000 miles. I changed it every 3000 miles until last year when i figured i might as well try and extend it to 7500 which is what the Subaru recommends. My first analysis was done after 37,624 miles with 4427 miles on the oil. The numbers were all below normal so i let it go to 6261 miles this time. All the numbers are up quite a bit this time.

code:
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6261 / 4427 / Uni avgALUMINUM 4/ 3/ 3CHROMIUM 1/ 1/ 1IRON 14/ 9/ 8COPPER 5/ 4/ 5LEAD 7/ 1/ 5TIN 0/ 1/ 1MOLYBDENUM 92/ 59/ 71NICKEL 0/ 0/ 0MANGANESE 0/ 0/ 0SILVER 0/ 0/ 0TITANIUM 0/ 0/ 0POTASSIUM 0/ 2/ 1BORON 155/ 130/ 99SILICON 15/ 11/ 7SODIUM 3/ 4/ 6CALCIUM 3195/ 3047/ 2577MAGNESIUM 18/ 13/ 114PHOSPHORUS 874/ 687/ 778ZINC 1084/ 706/ 917BARIUM 0/ 0/ 06261 / 4427 Sus Viscosity 60.5 / 57.5 Flashpoint 380 / 370 Fuel % < 0.5 / < 0.5Antifreeze % 0 / 0Water % 0 / 0 Insolubles 0.3 / 0.4

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Feedback from Blackstone: Silicon increased a little, and along with it, engine wear. The oil was run about 1,800 miles longer than the first sample, and that accounts for most of the increased wear. Silicon can often show problems developing at the air filtration, so we suggest checking this system on your engine. These metals are not enough above universal average levels to show a mechanical problem developing in the engine. No fuel dilution or coolant was found and insolubles were low showing good oil filtration. Other than the silicon, nothing unusual showed up at 43,885 miles.

The cut & paste didn't come out well but the lead was what were concerned about.

 

[Bobert]

Uhh ohh, could there be more leaded gas floating around Georgia.

Other high lead reports were coming from northern Georgia.

 

[LubeOiler]

Patmans oil report was fine if things don't get better soon I may start getting my oil from north of the border.

 

[Cutehumor]

send this report to the EPA in Georgia or D.C!

 

[zoomzoom]

if the bearings were going woudn't tin and copper be way up as well?

 

[TooSlick]

The cause of concern here is the very high moly level. Subaru coats their piston skirts/lands with a dry film moly coating and the 200+ ppm of moly could indicate severe piston scuffing. It could also explain the increase in Fe and Al.

This piston scuffing would also significantly increase the main/rod bearing wear in the affected cylinder or cylinders. The piston is dragging up and down and significantly increasing the out of plane load on these bearings.

A dealership visit and compression test is in order here. I'd also discuss dropping the pan and examining the condition of the bearings....

 

[bulwnkl]

Is that an uptrend in the lead reading over these three intervals? The molybdenum does also look quite high; I didn't think M1 used that level in their formulations. FWIW, my older Subaru likes a 40-wt much better than a 30. I run 15W40 in it. Perhaps that's worth considering once you find out whether there's big damage inside.

 

[TooSlick]

The GF-4 version of this formulation uses about 90 ppm of MoDTC. There would typically be some decrease in these levels as the additive performs its' function. So a level of 200+ ppm is way out of wack.

This oil is very depleted - you can tell by the residual boron level - but I wouldn't expect to see a dramatic increase in lead levels,given the previous data. Of course those were the SL or SJ versions of M1 and had more robust additive packages....

It may simply be that the GF-4 stuff doesn't last as long as the higher TBN, SL or SJ formulations???

 

[jason07-1zzfe]

What oil was used in previous 2 samples?

 

[jsharp]

quote:

---

Originally posted by TooSlick:
The GF-4 version of this formulation uses about 90 ppm of MoDTC. There would typically be some decrease in these levels as the additive performs its' function. So a level of 200+ ppm is way out of wack.

This oil is very depleted - you can tell by the residual boron level - but I wouldn't expect to see a dramatic increase in lead levels,given the previous data. Of course those were the SL or SJ versions of M1 and had more robust additive packages....

It may simply be that the GF-4 stuff doesn't last as long as the higher TBN, SL or SJ formulations???

---

Our friends at the API and at the auto companies are always looking out for us.

How to make a SM/GF-4 oil? Take your SL/GM-3 oil and reduce the additive package...

 

[TooSlick]

Jsharp,

1) Would you expect a very low TBN (acidic) oil to react chemically with this dry film coating of Moly on the piston skirts?

OR

2) If he is indeed getting leaded fuel, could this affect the moly coating on the pistons?

Those are the other two possibilities I see here....

 

[Mr Nice]

Was it really necessary for API & oil companies to change to (SM GF-4) specs ?? What was so bad with SL GF-3 specs ??

 

[oilyriser]

When I looked at an intact piston from my car's old engine, the moly coating had been rubbed off from the thrust surfaces, but there didn't seem to be any unusual wear after that. But it shouldn't increase suddenly.

Here's the EPA reporting website, for Georgia.

http://www.epa.gov/region4/home/contact_report.html

 

[jsharp]

quote:

---

Originally posted by TooSlick:
Jsharp,

1) Would you expect a very low TBN (acidic) oil to react chemically with this dry film coating of Moly on the piston skirts?

OR

2) If he is indeed getting leaded fuel, could this affect the moly coating on the pistons?

Those are the other two possibilities I see here....

---

I haven't worked much with those kinds of coatings recently, but all I've been told and read says that they are inert, and "chemically resistant." I also don't know what you would see for moly elevation in a UOA with normal wear vs. greater wear. It would stand to reason that you'd see elevated levels as the coating was worn away.

One of the guys here who does engine building with modern techniques should fill us in if they know more.

It seems like the use of leaded gas or another additive is the only time we we see lead this high.

 

[Bror Jace]

All this talk is fine (and interesting) but I think ru_bunky needs to switch to a significantly thicker oil ASAP before this thing croaks.

Maybe M1 15W-50 ... or a non-synthetic 40 weight?

Heck, it's probably too late already.

--- Bror Jace

 

[TooSlick]

I'd try using some autoRX - perhaps this engine has some stuck rings which are causing a piston or pistons to drag in the cylinders? A double ARX treatment should free up these rings and minimize this piston scuffing.

My original advice about a dealer visit and pan drop still holds, however the "non-invasive" choice for me would be the AutoRX treatment ASAP....

Ted

 

[ru_bunky]

Thanks for all the responses. After checking my records, I found that the dealer did an oil change @ 111,000 as part of the 100,000 mile service. So, I put 7,600 miles on a non-synthetic. ouch.
Here are my official records:
3/14/2004 95352 5W-30 dino
5/22/2004 99280 10W-30 Synthetic
11/27/2004 109237 5W-30 Synthetic
12/28/2004 111104 5W-30 dino
6/5/2005 118694 5W-30 dino

I changed the oil tonight, after 3,500 miles and will report back on the results when I get them from Blackstone.
Keep your fingers crossed.

 

[TooSlick]

The oil the dealer used (Pennzoil?) may well have had this much moly in it.

In that case, I'd say the lead is from more of the leaded fuel that is showing up in parts of Georgia....


TS

 

[LubeOiler]

I'd bet on "anomaly"* unless aluminum's still elevated next time. My reasoning? The other wear metals are solidly within normal limits.

*As in contaminated sample, or contaminated reaction vessel at the lab, etc. File under "s(tuff)*** happens". Passing this on from another thread. It seems to me either were getting a lot of bad cars lately or just bad reports.