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Just got my oil analysis results back and the copper levels have almost doubled.
First thought is valveguide wear but none of the other bronze materials (Sn,Al,Mn,Ni,Zn) have spiked. Any engine gurus here that could offer insight and/or recommendations?
I've been thinking about doing compression & leakdown tests - I even bought the kit. This will probably motivate me to do it. Car is running great and not burning oil. Is it OK to continue to monitor?
Strange. Your viscosities are great/strong. But your phosphorus and zinc are low/weak. What oil are you running? What did you run before this last UAO?
While your copper increased, it's not crazy high.
I suggest you do another oil change and UOA in 1,000 miles and see what copper is doing again.
This is why I like doing consistent patterns of UOAs. Catch stuff early. Good job.
My WAG is you recently changed oil brands (maybe now DT50) and the Turbo is saying "GTFO".
Interesting posting. It seems to cause more questions:[*]In absolute terms is 24 parts per million a significant value?[*]Could it be within a variance range that is reasonable?[*]Can a conclusion be drawn with such a small data set and no control data to compare it to? Is there a good source of additional comparitive data to put the poster's concern in context? Andy
It's not significant as a value alone. It's only significant because the delta and change from prior tests on his motor. He has plenty of good useable data points. I suspect he started using a different oil a year ago, and the Turbo does not like/prefer it.
Actually, I've been a Mobil 1 15W50 guy since I got the car. Pretty sure the 2 indy oil changes I got before doing it myself were also M1 15W50 and no idea what PO used
The dark grey column next to my current data is average aircooled 911s at Blackstone, column on far right is average of all gas motors so there is some statistics to support.
Oil pressure is good, only comes down to 3 when engine is good and hot and at idle. Pegged at 5 all other times.
I should correct saying she burns no oil, I took out 9 qts and put in 10 and it was above 1/2 way on dipstick so an average would be 1qt per 2500 miles.
The dark grey column next to my current data is average aircooled 911s at Blackstone, column on far right is average of all gas motors so there is some statistics to support.
The grey column is actually the average for your motor. The far right is supposed to be aircooled Porsche engines.
The dark grey column next to my current data is average aircooled 911s at Blackstone, column on far right is average of all gas motors so there is some statistics to support.
No. That's not correct. The first grey column is your car's average.
The second grey column is the Blackstone average for 3.6 liter 993 turbo'd motors. Blackstone will throw out any data points that excessively deviate from these values like raced/tracked/damaged motors. I bet there are no more than 50 cars in the Blackstone average. Ask them. They will tell you.
If I were you, I'd switch to Mobil V-Twin. Need to get your zinc and phosphorus back up.
Thanks KNS & Lex, I think you're both right! Do you think this is serious enough to warrant action like changing to V-Twin in 1000miles & retesting? Retesting in 1/5 of the miles should bring copper down to 5 right if wear is consistent? Or should I do the comp/leakdown, maybe inspect exhaust valves by taking off header and if all good carry on enjoying the car? Thanks for the support - it's good to be able to talk with knowledgeable folk
V-twin is a better oil.
I think it would be prudent to change to V-twin and retest your oil analysis within 1000 miles. I'd want to know if copper is going up, stabilizing or possibly coming back down
Based on the retest used oil analysis then decide if you want to do any leak down and compression.
Do you always keep RPMs below 4000 before the oil temp is in the 180s?
I have a BMW 325i daily that had escalating copper readings several years ago. I spoke with a tribololgist about the problem as I had planned to keep the car for a long time. He stated to stop using the crap BMW recommended oil and get something with higher zinc and phos. I started using Shell Rotella T6 5W-40 and the copper started dropping back to normal levels - all readings have been normal for years now (almost 200,000 miles on it).
Not saying this will fix your problem, though... For the 993 I use a mix a Mobil V-Twin and 15W-50.
11-25-2015, 10:41 PM
increased copper in oil analysis
