911 metal flakes in oil

akapple · 05-24-2006, 06:43 PM

I just changed the oil in my stock 1981 911 after it was stored for the winter (ran it for awhile first). I noted in the drainage a small amount of what looked like gold dust!! I presume this is brass? I also noted small amount of what appears to be aluminum flakes. Can anyone tell me where these metals are in the engine and what might be going on? The engine does not make any strange noises and seems to run just fine.

Steve@Rennsport · 12:00 AM

Hi:

Brass is found on the distributor gear on the crankshaft, in the wrist pin bushings, and rocker arm bushings. (edit: valve guides too although its bronze)

Aluminum flakes may be from the intermediate gears, pistons, and some assorted oil galley plugs.

I would perform an oil analysis for a few changes and take note of any changes.

Questions: How many miles on your motor? What oil are you using?

mb911 · mb911's Garage

I have a bit of brass in mine as well. It runs great and did a top end about 4000 miles ago (new guides etc). I am thinking the dizzy gear on the crank is going bad. I hope it makes it the summer!!!!!!

donstevens · donstevens's Garage

I don't see any metal in my oil but the analysis says there are fairly high readings of copper. I am thiinking valve guides.

I had an old Bimmer that had visible metal in the oil but the oil analysis reportwere fine. It is still going stong after 250,000 miles.

The bottom line is, have your oil analyzed and see what the wear report says. Go to www.oaitesting.com or www.blackstone-labs.com for kits.

Don

akapple · 05-25-2006, 05:03 PM

Thanks for the replies. To answer the question of how many miles. Car has 112,000. I use Castrol 20-50 GTX oil. Don thanks for the connetion to oil testing. I have never had this done before.

rnln · 05-25-2006, 05:25 PM

on my first 2 oil changes, I saw lot of those sparkling. I know the PO have the habit of starting the engine and vroom right away, and hard. I change my oil every less 3k miles and have seen them after the first 2 oil changes.

randywebb · 05-25-2006, 08:26 PM

the chemical analyses will detect microscopic particles that the eye cannot see; possible to have metal particles so small they go thru the oil filter and stay suspended in the oil nearly forever...

Hetmann · 05-26-2006, 06:38 AM

Most likely bearing material. I see a rebuild in your future.

Wil Ferch · 05-26-2006, 07:54 AM

quote..." Most likely bearing material. I see a rebuild in your future..."

Why do you say that?

Bearing material is almost always a mix of lead / antimony /tin...nothing "gold flake" about it. Can you elaborate ?

- Wil

atlporsche · 05-26-2006, 09:22 AM

c'mon guys. it's that extra exclusive metal flake oil...I mean paint...ummm oil.

sjd

DarrylD · 05-26-2006, 09:57 AM

Just to satisfy my curiosity, I make it a ritual to do an oil filter autopsy with every oil change on my engines... same with the fuel filters. I can't imagine a better (free) engine condition analysis tool. I use a chisel and tin snips to open mine but now I see that Weltmeister sells a fancy tool to make the process of opening the canister neater.

http://www.***************/ProductPage.aspx?pid=110679

A magnet in a small baby food jar of carburetor cleaner determines the material type on the sludge I drop into it by swirling them around in the liquid and seeing what sticks and what doesn't. As mentioned above, brass and bronze is easy to detect based on its color.

Not really a quantitative answer like a lab analysis, but a good gut-feel of how broken-in or healthy an engine is. Comparing the outcome with good healthy engines in the "family fleet" has given me an idea of what's normal and what's cause for concern and gives me a warning sign when there's a significant change or if the used car I just bought has issues. I think it's a good mechanics practice to understand what "normal" is.

mb911 · mb911's Garage

Quote:

Originally posted by DarrylD
Just to satisfy my curiosity, I make it a ritual to do an oil filter autopsy with every oil change on my engines... same with the fuel filters. I can't imagine a better (free) engine condition analysis tool. I use a chisel and tin snips to open mine but now I see that Weltmeister sells a fancy tool to make the process of opening the canister neater.

http://www.***************/ProductPage.aspx?pid=110679

A magnet in a small baby food jar of carburetor cleaner determines the material type on the sludge I drop into it by swirling them around in the liquid and seeing what sticks and what doesn't. As mentioned above, brass and bronze is easy to detect based on its color.

Not really a quantitative answer like a lab analysis, but a good gut-feel of how broken-in or healthy an engine is. Comparing the outcome with good healthy engines in the "family fleet" has given me an idea of what's normal and what's cause for concern and gives me a warning sign when there's a significant change or if the used car I just bought has issues. I think it's a good mechanics practice to understand what "normal" is.

I do as well and never have found anything in mine. Thats what makes me wonder where mine has come from. It could be remainder of what was in the oil lines previous to my engine install

DarrylD · 05-26-2006, 10:54 AM

That is strange, kind of like strange noises, it will probably get worse over time if it's something serious and you'll just have to keep an eye on it. The important thing is you've aware of it and now can monitor it.

Rob 930 · 05-26-2006, 11:38 AM

An single oil analysis to determine the elemental makeup and quantity of contaminants is interesting, but it may not tell you all that much. It really needs to be done periodically so you have a baseline and can get a sense for a deviation from it. A single test may only serve to scare you unless you have knowledge of what "normal" is for your engine or for an engine like yours. In the machinery industry, including fleets of heavy trucks, such tests are routinely done, and the *changes* in metallic makeup and content are monitored. Obviously, if there are big chunks of metal, there's no point in doing the test. The problem with doing a single test is that unless there is an unquestionably high content of some contaminant, which may be obvious to the naked eye, it may be hard to interpret the results definitively.

Hetmann · 05-26-2006, 12:30 PM

The reason I think it is bearing material is because that's what it was in my case. I saw brass to copperly colored shards in my oil filter. My wrench told me to stop driving the car immediately. Once we got the motor torn apart I saw where one of my main bearing had spun. Bearing material exhibits various colors because it has a substrate and a coating on it. There certainly are other bits and pieces that could be flaking, but why take the chance on doing more damage to your engine. Metal pieces in the oil are a red flag.