Does anyone know where all the copper is coming from in GM engines. It seems to be present in UOAs at a disproportionate level compared to other metals. The very high Cu also seems to me to be somewhat unique to GM. I said "seems" (twice) because I don't know. Is there a free penny in the bottom of every GM oil pan?
GM and copper
- Thread starter GMorg
- Start date
- Status
Kestas
Staff member
I believe it can only come from the journal bearings on the crankshaft, unless the valve guides were bushed with brass.
I dunno... I've seen UOAs of Honda motors still spitting copper well past 20,000 miles. My Hyundai V6 showed 126 ppm on its first UOA (3,000 miles) and that was after the initial oil change at 600 miles. My latest UOA, at 18,000 miles still shows 12 ppm copper. I'm wondering whether some manufacturers apply a sacrificial plating of copper to aid long term run-in.
(When it got to the point that the value of copper pennies exceeded the coin's nominal currency value, the U.S. Mint began striking pennies from copper plated steel. Even common "copper" electrical wire is often copper plated steel.
)
(When it got to the point that the value of copper pennies exceeded the coin's nominal currency value, the U.S. Mint began striking pennies from copper plated steel. Even common "copper" electrical wire is often copper plated steel.
Actually, the pennies minted today are copper plated zinc alloy. The 1943 pennies were zinc coated steel. And the 1944-46 pennies were made from salvaged used ammunition brass.
I strongly suspect that Terry Dyson has the answer to your question.
Seems to me that this issue was explored during past years here at Bitog, and the source is not a critcal wear surface, i. e. not crankshaft, rodbearings, camshaft, lifters, etc.
Seems to me that this issue was explored during past years here at Bitog, and the source is not a critcal wear surface, i. e. not crankshaft, rodbearings, camshaft, lifters, etc.
Possibly from a copper line to an oil cooler, something like that. I think that is a source of copper in the Duramax diesels.
k1xv they do not use copper lines in this day and age on vechiles. The copper on GM vechiles remains high for about the first 50,000 miles so I doubt it is a sacrifical plateing. I do not know if it is the cam bearings,thrust flance on the crank bearings or the buschings for the oil pump. I can tell you that their is not a free penny in the oil pan! What bothers me is how long it takes to trend down and in some cases it never does trend down. That wear has to be comeing from some place and their has to be a limit to how much extra material can be lost before it becomes an issue.
About the only copper plated steel electrical wire you'll find at your local home improvement store is the center conductor of RG6 television coaxial cable, and only because it doesn't affect the ability of the cable to carry radio-frequency signals. (It DOES, however, affect the ability of the cable to carry DC current as well as low-frequency components, and for that reason a solid copper core coaxial cable is often specified for carrying power or for baseband video CCTV use).
Some suspected places: Journal bearings (crankshaft, con rod, camshaft, oil pump bushings, rocker arms), thrust bearings (crankshaft, camshaft, oil pump drive bearings)
Slipper bearings (vavle guides, cam followers, hydraulics follower internals, rings, pistons), vavle seats (bronze alloys) and finally, there are some aluminum alloys with coper content and the iron cylinder liners molded in with the aluminum blocks have some coper content.
Slipper bearings (vavle guides, cam followers, hydraulics follower internals, rings, pistons), vavle seats (bronze alloys) and finally, there are some aluminum alloys with coper content and the iron cylinder liners molded in with the aluminum blocks have some coper content.
Kestas
Staff member
The copper content in some aluminum alloys is roughly 3%... cast iron has typically 0.25%. You'd have to see a lot of aluminum or iron and be worried about its levels in the oil before you'd be worried about copper levels.
Rings & pistons?... I don't think so.
Hydraulic follower internals & valve seats?... I've never seen copper in them. (Maybe I'm not up to date).
Otherwise, Mitch has a good list.
Rings & pistons?... I don't think so.
Hydraulic follower internals & valve seats?... I've never seen copper in them. (Maybe I'm not up to date).
Otherwise, Mitch has a good list.
So, it is a mystery indeed.
By the way, the copper plated zinc penny switch was made in 1983 (I'm a collector). They also tried brass in 1942, but the tin in the alloy made them unsatifactory. By 1944, tin was in shortage and they had begun to leave it out of shell casing brass. The shell cases were then acceptible. Also, a few 1943 pennies were stuck using brass slugs and a few more 1944 pennies were struck with the steel slugs. These are among the most valuable pennies around. Maybe GM uses these mis-strikes in the oil pan. It could explain the financial problems...I guess that is just silly since they probably don't use pennies in oil pan anyway.
By the way, the copper plated zinc penny switch was made in 1983 (I'm a collector). They also tried brass in 1942, but the tin in the alloy made them unsatifactory. By 1944, tin was in shortage and they had begun to leave it out of shell casing brass. The shell cases were then acceptible. Also, a few 1943 pennies were stuck using brass slugs and a few more 1944 pennies were struck with the steel slugs. These are among the most valuable pennies around. Maybe GM uses these mis-strikes in the oil pan. It could explain the financial problems...I guess that is just silly since they probably don't use pennies in oil pan anyway.
Copper in the anti sieze used to build the engines. We use it where I work during assembly of engines.
http://www.midwayautosupply.com/detailedproductdescription.asp?656
http://www.midwayautosupply.com/detailedproductdescription.asp?656
I hadn't thought of that. Great! Do you know that a copper based anti-sieze is actually used to assemble GM engines? I am a little suprized that is stays around so long though...if it is an assembly lube.
Kestas
Staff member
I find it hard to believe antisieze is applied to bolts in production engines. Manufacturers go through great lengths to do away with extra steps in production. Plus, the logistics of using antisieze in production is too difficult.
I still say copper can only come from the journal bearings.
I still say copper can only come from the journal bearings.
Cam bearings.
quote:
Originally posted by Ray H:
Even common "copper" electrical wire is often copper plated steel.)
HOLY SMOKES! That brianl703 really knows his wire.
Copper is whack in my UOA (although it could be caused by another issue we have: you'd have to read the thread)
http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=3;t=003343
...but, Blackstone said that they typically see alot of it in GM Engines. I saw another guys truck post that also had alot of Cu in it.
What about the machines/hoists used to assemble the engines? The robots and their arms and joints? Do they used copper bushings? Could the assembly line be contaminated? Anyone here work on a GM engine assembly line?
http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=3;t=003343
...but, Blackstone said that they typically see alot of it in GM Engines. I saw another guys truck post that also had alot of Cu in it.
What about the machines/hoists used to assemble the engines? The robots and their arms and joints? Do they used copper bushings? Could the assembly line be contaminated? Anyone here work on a GM engine assembly line?
Zaedock wrote:
"Could the assembly line be contaminated?"
"Could the assembly line be contaminated?"
Antisieze compounds are specified for certain fasteners, so it wouldn't surprise me to see it used in GM's factories. They would only use it when absolutely necessary, though. I would also suspect there might be some sort of sealant that causes the high CU readings. I seem to remember a posting about that quite some time ago.
- Status
Similar threads
