So now what? Post analysis questions

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I know you can't judge things off 1 UOA, but....

Here's a link to my UOA:

http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=3;t=003331

So my question is, if I dropped 6 points off TBN over 2k miles, should I be using anything LESS than an HDEO? What about synths? I replaced this stuff w/ Pennzoil Platinum 5W30, would the TBN drop in it as fast as it did in the Castrol?

Viscosity wise, that lead MAY have been a one-time thing, but if it wasn't, should I stick w/ a heavy oil?
 
You have an excellent oil in the thing now. Do another UOA at about 5000 miles. The lead is a little high but should come down with the Pennzoil synthetic.
 
Yeah, but I worry if the lead has been that high for a while, what condition are my con rod bearings in? Hopefully it hasn't been like that a while though and just high b/c of arx...

This is a turbo engine, but man, it seems like it was extra tough on that oil. Am I wrong?
 
I'm not sure how much of an effect 10 oz. of ARX has on the oil used, but that 40wt seemed to become a mid-upper 30wt quick. If the engine's spec'ed for a 40wt, perhaps it's having come out of grade and possibly spirited driving on those distant interstate ventures resulted in some contact. If you've been using synth solely as I think I gathered, and by my "I'm no expert" look at your UOA, there doesn't seem to be much that supports old deposit suspension
dunno.gif
. Perhaps a particle or two were tracking through a bearing causing a momentary increase in lead numbers - I've read a similar occurance from a UOA around here somewhere.

Things may be fine over the next interval, but as for the drop in visc. (almost 25% diff. - perhaps alotted under the SL spec.?), that's surely interesting.

The drop in TBN could point to the severity of the environment this oil and add pack were subjected to, but not neccessarily so. It's been said that a high number with a virgin oil isn't per sa a good thing, but it's how it retains it that matter most. At 6 there's still a ways to go, and some tests have shown that the TBN trend can be anything but linear.

Rest easy and do a UOA at your next oil change or somewhere there in between if you feel the need. There's little one can do at this point I think and worrying would do little more than tant one's day to day experiences of life.

biggthumbcoffe.gif
 
What's weird is the filter that I took off w/ this change DID have a decent amount of gunk in it. Also, worth considering...I was coming off a rinse phase using 5W30 Supertech. Perhaps what was left in the sump affected the viscosity readings. I've spoken to some other saab folks who've used this oilmedic test and they DID say all their viscosities were on the low side, so perhaps this is a consistant low reading of viscosity? As for spirited driving, I am 29 but drive like I'm about 89. With everything I've read about this car's engine, I'm afraid to really nail it!

No, I haven't been using synth. I suspect the orig. owner didn't either. The only synth I've used was M1 EP 5W30 on my first arx clean phase. After that, since I figured I'd be doing short intervals, I've been using dino until my last change, when I threw in Pennzoil Plat 5W30.

To further complicate things, it may not be a clear case of bottom end bearing wear. Someone pointed out the fact that there are some leaded bushings in the upper valve train!

One thing one person pointed out was so far, there doesn't seem to be a whole lot of difference in numbers between synth blends, full synths, synth HDEOs and dino HDEOs.
 
Brian,
Here's a link to results for my '03 Aero. I think you've seen it before:
http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=3;t=003233

The first check on that car was a couple years ago, a 3,776 run on the mystery oil from the dealer's "free" 10k service. Suffice it to say I'm happy with M1 5W-40 and 5k runs. Unless it turns out the "new" 5W-40 is not actually the same as the old, I'm going to continue using it as long as I can find it.

IMHO, these cars should see only XW-40 full synthetics. 15W-50 is probably fine for warm climates too. I'd run the PP for 5k and send in a sample. See what happens and consider going to a 40 for the next fill.

jeff
 
Thanks for the reassurance TallPaul, I just worry since these things have a way of going south. It's impossible to find a good low mileage 9-5 engine-there have been that many replacements.

Oh yeah, Jeff, I forgot about your UOA! Good to have another one on here.

I think that T&SUV would probably be the best oil to use, and it's really not that expensive given the skyrocketing price of oil. I bought a bunch of the dino stuff on sale and figured the 15W wouldn't be that bad down here. I certainly won't go extended drains w/ it. As for the Pennzoil Platinum 5W30, I have a habit of buying oil at Wal-Mart when we make our Sunday pilgrimage. I haven't seen any 40 weight there or at Advance Auto. I haven't checked Autozone or PepBoys though. I may run one more w/ the Pennzoil and then one in the summer w/ the Castrol again.
 
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