Question about copper

[INDYMAC]

After researching various oils' technical data sheets, I always notice a performance test result listing "copper corrosion rating, ASTM D-130". How important is this test for selecting a good oil for a particular application? Would it be more important for those people experiencing elevated copper readings on their UOA's? Thanks for any insight you could give on this topic.

 

[Kestas]

This test shows how aggressive the lubricant is in attacking copper and copper alloys. The aggressive component is usually the sulfur compounds in the lubricant as EP additives or residual sulfur from refined oil. Aggressive amounts of sulfur in the lube can attack any copper-based component in the engine, such as journal bearings.

Some engines use aluminum journal bearings and may have no copper alloys contacting the oil. For these engines the copper corrosion rating would not be a consideration.

Just remember that sulfur attacks copper and ASTM D-130 checks for this.

 

[toocrazy2yoo]

I would imagine PCMO in any modern engine has the copper covered, so to speak. This has been an object of curiosity to me in that my 5-speed manual transmission requires GL4, and NEVER GL5 as GL5 has no "yellow" metal or copper corrosion protection, and will (supposedly) wreck your synchros. Meanwhile, M1 sells full syn GL5 for 14.00/qt. And it'll wreck my synchros???

What has copper inside an engine, anyway, main bearings?

 

[Patman]

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What has copper inside an engine, anyway, main bearings?

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Cam bearings

 

[toocrazy2yoo]

Yo, Pat! Thanks..

So is the old saw that GL5 eats the yellow metals specc'd for GL4 true? Not much GL4 around anymore, and not in syn that I've seen, in any case..

 

[JAG]

Copper leaching doesn't settle down in engines until a chemically insulating film is formed over the copper alloy parts. 100 PPM of copper leaching in a UOA can represent less mass of copper lost than a measured 10 PPM from chunky (sizable) copper wear particles. Multiple UOAs on same oil will show the trending and whether it's leaching (seen as decreasing concentrations as engine ages) or from wear.

 

[uconn1150]

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Yo, Pat! Thanks..

So is the old saw that GL5 eats the yellow metals specc'd for GL4 true? Not much GL4 around anymore, and not in syn that I've seen, in any case..

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I believe Amsoil, Redline, and SF are GF4. I hope SF comes back. I'm safe for about 6 months.

 

[INDYMAC]

OK, so if your engine had copper cam bearings would a rating of 1a be acceptable to use in your engine? Or is there a better rating to use?

 

[bruce381]

1A is the best result on that d-130 test basicly NO corrosion at all copper metal inhibitors are used in PCMO oils ince ZDDP will be aggresive depending on type of ZDDP used tho to copper if un inhibited

 

[double vanos]

I ran GL5 lube in my Trans Am and at 76k the trannie took a rebuild due to main and countershaft wear and synchro failure.

I know well the corrosion that sulfur puts
on yellow metals in transmissions - do yourself a favor and run Redline or any of the popular gearlubes designed to preserve synchros...Royal Purple and GM synchromesh transmission fluids are a good place to start.

Cheers!!

 

[wgtoys]

If you look carefully you can find gear lubes dual rated for both GL-4 and GL-5. Better yet, use a purpose built gearbox lube such as those offered by Redline, Amsoil, Royal Purple and a few others.

 

[INDYMAC]

Even though we're getting a little off topic here, I guess the D-130 test rating would be good to know for someone who perfers to use a motor oil in their transmission over a GL rated gear oil or designated manual transmission fluid.

 

[Bill Plock]

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Copper leaching doesn't settle down in engines until a chemically insulating film is formed over the copper alloy parts. 100 PPM of copper leaching in a UOA can represent less mass of copper lost than a measured 10 PPM from chunky (sizable) copper wear particles. Multiple UOAs on same oil will show the trending and whether it's leaching (seen as decreasing concentrations as engine ages) or from wear.

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Jag,

Excellent explanation. This has been my exact experience with the last three new GM vehicles/engines I’ve purchased (3.1L V6, 6.6L Duramax, 3.4L V6) . Copper levels in the UOA starts out high and then trends down (see the Duramax UOA link in my signature). I’ve not been too concerned since Si and other wear metals have been low when Cu was elevated.