M1 0W-40, 17½ months/17,000 miles, '90 Saab 900, 2.0L 16v

[Eiron]

code:

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Vehicle 1990 Saab 900, 2.0L 16v I4 (N/A)

Miles on engine 191,180

Oil type Mobil 1, 0W-40

Miles on oil 16,986

Time on oil 17 months, 2¾ weeks (30.Oct.04 – 18.Apr.06)

Oil capacity 4 qts

Oil added 2.63 qt

Oil filter Purolator PureOne PL10017, changed at previous UOA sample (11,892 mi)

Air filter K&N drop-in, last cleaned at 150,000 miles

Driving Use 50% city, 50% hwy – daily commuter (40 or 65 miles on surface streets) & weekend errands

Sampling method Vacuum pump via dipstick fill tube

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Copper 14

Iron 20

Chrome 2

Lead 3

Aluminum 3

Silicon 4

Molybdenum 60

Sodium 12

Calcium 2523

Tin 1

Potassium 2

Magnesium 37

Zinc 930

Water Neg

Glycol Neg

TBN -

Viscosity 13.5

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Lab S.O.S. Fluid Analysis, H.O. Penn Machinery

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Previous UOA run at 12k mi.

The only odd things I can think of were:
1) After pulling the sample, I discovered that the smaller of the two PCV valve fittings was completely blocked at the valve cover. At some point (I don't know when) this smaller hose came off the throttle body fitting & so I've been getting fresh air rather than additional venting of the crankcase. In newer Saabs, a compromised PCV system has been linked to sludged engines. Since it's the smaller diameter hose on my older engine, I don't know if this impacts my oil quality or not.
2) I put in a new clutch, which required new thread sealant on the bolts holding the flywheel to the engine. Since these bolts penetrate into the engine, thread sealant is required to keep motor oil from seeping out & creating Spin-Art™ all over the clutch. Rather than using an "approved" engine thread sealant, I used what I had on-hand: Oatey's Great White™ Pipe Joint Compound with Teflon®. I have absolutely no idea if this would impact the UOA.
3) The oil level was quite a bit down when I took this sample. Nearly 1/2 a qt. I try to keep it topped up as close to Full as possible, due to previous discussions & examples on this site that show how much better off you are to keep your oil top-ups fresh. Being 10% low on oil might show up as higher levels of contaminants & wear in the UOA. Oh well...

 

[Steve S]

What is there to say!!!

 

[TR3-2001SE]

Looks great. I have just switched my Miata to the oil from the standard M1 which seems a little weak to me at this point. Hope I have nerve to go this far on this oil.

 

[Cutehumor]

it's been 17 months already since you last posted a UOA on this engine? I remember your last UOA, it doesn't seem that long ago. Wear looks good; however, running this long IMHO would feel comfortable with a TBN if it's longer than a year.

 

[Pablo]

Excellent!! So the 2.63 added is for the whole run, correct?

http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=3;t=003224#000000

Who needs dino?

 

[Patman]

Looks good! Viscosity is good too, although I'm sure at some point it dipped down into the 30w range, and came back up again. But engine wear is very good, so that's the main thing.

TBN definitely would've been interesting to know here.

 

[Eiron]

Steve, thanks!

TR3-2001SE, I think this is the best oil to use in a non-turbo car! I'm only going this far (20k mi) to see how it holds up. Then I'll drop back to my normal short intervals of only 10k mi.

Cutehumor, you're right, it's only been four months since my last UOA on this engine/oil combo. It's been a year & a half since I started this interval.

Pablo, dude! You are correct sir! 2.63 qts over the entire interval. That's up a little from the one quart I normally see over a 10k mi OCI, but approx 1/2 qt was due to oil loss when I r&r the new filter. I don't r&r the filter on a 10k mi OCI.

Patman (& Cutehumor), the lab mgr talked me out of paying extra for the TBN. Her feeling was that it was just a waste of money, since you can infer the life remaining in the add pack from the basic UOA. And since I'm a cheap-a** bast**...

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One of the other things I forgot to say was that I changed from a "regular" ACDelco PF13 filter to a "micro-fine" Purolator PureOne PL10017. It's in the info, but I thought people might find something interesting about that...