oil sample

[Fred]

I just did an oil sample on my car and everything came back normal except for there was an unsually high amount of copper in it. Does anyone have any idea where this copper is coming from? I use 10w30 royal purple and I had 4700 miles on that oil sample, my car has 82,000 miles.

[StrtRacer98]

how do you sample your oil, ive never heard of this.

[CDNFB]

I've never done the oil sampling on an automobile, but we do do it in aviation.

How do you know the copper level is unusually high? Does the company that did the analysis for you compare the results from your sample to their base line (or normal sample) for a 3800, which should also account for type of oil and duration of use (you said 4700 miles, their standard might be 3000 miles).

A one time sample doesn't tell me much of anything. Maybe it's normal for your engine, with this type of oil, with a 4700 mile duration to have high copper levels.

To really be able to monitor the wear of the engine you have to do regular oil sampling at consistent intervals to establish the normal trace material patterns. This way when you see a spike on a certain trace material you know something abnormal is going on, and what component is actually failing.

I'm not sure but doesn't the oil pump have bushings (aluminum/nickel/bronze) in it? (Bronze being the source of your copper)

DZ

[terminaldegree]

When you say high, how many PPM do you mean?
What lab did you use?
How long was the oil in the car?
How many miles on the engine?

GM pushrod motors are somewhat notorious for throwing a lot of copper. Mine does too. It is supposed to go down over time.

[BobbyZ72]

where the hell would copper come from? Unless it was in the oil already when you bought it. There is no copper in our engines. I think they made a mistake.

[terminaldegree]

bobby,

I have seen at least 30 different oil analyses of GM powertrain engines from various labs, and the one element that is almost universally elevated is copper. Here's one quote from another site talking about oil analysis:

Copper (CU), Tin: These metals are normally from brass or bronze parts, bearings or bushings and valve guides. Oil coolers also can contribute to copper readings along with some oil additives. In a new engine these results will normally be high during break-in, but will decline in a few hundred hours.

That's just a start. There's a lot more info, but I'm at work right now. Keep in mind that in oil analysis we're talking 5-50 parts per million, not an enormous amount. There is no mistake.

[BobbyZ72]

hmm, learn something new every day. I understand now, but id still be interested in seeing the results of regular oil vs. royal purple. Ive heard royal purple is the best, but is it possable it has large amounts of copper in it?

[terminaldegree]

Another thing the really OCD among us do is send the new oil away for analysis before we put it in, so that any wear metals are offset by whatever was in there in the first place.

1-2 ppm is the most copper I've ever seen in new, unused oil.
Copper isn't part of the additive package of any current motor oil I know of.

[Fred]

Ok my sample was 10w30 royal purple and I had 4700 miles on it. The car had 80,500 miles on it. I did my sample through Blackstone Laboratories. Everything was normal except for the copper which was 52ppm and normal is suppose to be 18ppm. The tbn was 2.5 so I still could have gone longer on that oil.

[terminaldegree]

Hey Fred,

One sample is nice, but getting a TREND is the key. I'm pulling up my last 3 oil analyses right now...

Sample total mileage - Copper in PPM

37,600 - 47
42,600 - 41
47,300 - 38

I run synthetic oil always, and limit my intervals between changes to either 5,000 miles or 6 months. You can see that mine is still high, but it seems to be headed in the right direction as the engine wears, so I'm not that worried.

How were the other wear metals? Sodium and Potassium? Silicon level? The k&n and the 160 degree stat might not be helping things...

[Fred]

Sodium was 9ppm, potassium 0ppm, silicon 6ppm,aluminum 3ppm, chromium 1ppm, iron 15ppm, lead 3ppm, tin 1ppm, molybdenum 106ppm, nickel 0ppm, manganese 1ppm, silver 0ppm, titanium 0ppm, boron0pm, calcium 1770, magnesium 963ppm, phosphorus 713ppm, zinc 853ppm, and arium 0ppm.

[xFirex99]

Fred,
Is that your reciepe for cookies? :D

[terminaldegree]

-All the wear metals except the copper look pretty good. I have lower Iron wear than you, but higher lead than you do.
-Single digit sodium, potassium are ok; no coolant leaks probably.
-Single digit silicon with a K&N filter is VERY good. Don't mess with you air filter... Most K&Ns let in much more dirt than that.

I wouldn't be overly concerned. If you drive the car hard, don't extend the oil change interval further. Try to run the same mileage and then sample again and see if things are trending down or getting worse.

If you want to post up the other numbers [water, antifreeze, viscosity, flashpoint, insolubles] feel free.

[Fred]

Ok sus viscosity @210f was 61.3, flashpoint 410, fuel was <0.5, antifreeze 0.0, water 0.0, and insolibles 0.3

[terminaldegree]

ok all that stuff looks just great. Oil stayed in grade, your oil filter is working well for you and you don't have a combustion problem or coolant leak.