Very fine brass residue & flakes in oil: help me make a potential problem checklist

[GN SBS]

Hi folks,

Changed the oil today and noticed that the oil appeared infused with a very fine brass (or gold in color) metal suspension. There were a few larger particles (think salt grain and smaller), but largely just a very fine gold tint to the oil. Metal does not respond to a magnet, hence my assumption that it's brass. Also noticed a haze on the oil that was not obviously metallic, but was not the usual.

I haven't yet cut the filter open to see if there's a gold mine in there.

I'm hoping folks can help me to put together a list of potential sources ; my inital thoughts on things to check:

* rod and main bearings
* cam bearings
* bearings in turbo

Any other ideas appreciated.

I suppose I'll start by dissecting the filter and dropping the oil pan to see if there's more fine grit there.

Thanks,
Scott

 

[1badTTA]

the best way to cut open the filter will be with a large tubing cutter (like used for copper pipes) and it will just shear the metal.

I would have to assume that it is bearing material in your oil, have you had lower than normal oil pressure lately?

 

[VIN7]

clean the particles really good, or look at them under a microscope if possible. The salt grain size leads me to think that this is aluminum from the oil pump housing and it looks gold due to the oil tinting it. Pop the oil pump cover off and look for scoring. If you were down to the brass in your bearings, wouldn't you think there would be a lot of metal in your oil? Maybe you could rent a big tubing cutter to open the filter.


Mike

 

[GN SBS]

Thanks for the feedback everyone.

Vin7: There were very few larger particles-- mostly the extremely fine bronze suspension and if it wasn't for that I never would have noticed the 3 or 4 other misc flecks. Microscope is an interesting suggestion; it would be neat to see what the suspended particles looked like up close.

Keep em coming folks.

 

[J Banning]

Scott,
Sorry to hear the bad news.

Did you save the oil? I'd like to see it.

-Banning.

 

[GN SBS]

Banning: Yes, I drained the oil from the filter and from the pan into separate containers and kept em along with the filter.

Maybe I should fill my trusty flask with the oil and sit it on my desk to remind myself of my woe.

-S.

 

[geno]

Check the thrust on the crank Thats where the brass comes from

 

[KWIKR 1]

seen something like that recently, Thrust bearing . It was a bronze/copper colour fine powered metalic in the oil . It was so fine that it would stay suspended in the oil even after sitting for sometime in a container .

 

[Sleeper]

Tim, is a bit of an expert here. Kinda knows a lot about thrust bearing failures, bearing analysis, and copper/bronze metallic stuff in the oil.

Paul

 

[bruce]

With a long screwdriver, try gently prying the crank back and forth.
If it goes more then a few thousandths, you've eaten the trust bearing. Usually it's obvious when too much is too much.
If you've had good oil pressure, that would be where I look first.

 

[GN SBS]

Thanks for the continued support.

Oil pressure was decent at just less than 20 psi @ hot idle. I heard some ticking in the drivetrain a while back and had been watching the oil pressure and it MAY have been off 2 psi or so, but it did not see a major drop-off.

In thinking about causes:

* I swapped injectors and made some other changes recently and it sat for a couple of weeks while I found the time to work on it. I had some louder than usual tapping in the driveline shortly thereafter and I'm wondering if I didn't do enough cranking to build oil pressure before starting her back up.

* I also run alchy injection-- if you're in the know, what does your experience suggest about alchy and bearing life?

Thanks,
Scott

 

[Sleeper]

IMHO
It wouldn't hurt to pull the pan and a cap or two. Why spend the time guessing. Either way it sounds like you have a bearing problem. Have you been beating on the car... getting some knock?

Paul

 

[1970gsx]

Have you been beating on the car...

Doesn't everybody?

 

[J Banning]

Here's something worth thinking about...

My machinist was telling me that alcohol is pretty hard on your bearings. His experience is mostly with guys running alcohol dragsters, but perhaps this also bears some weight regarding our cars? He was saying that alcohol doesn't dissapate the same in your engine oil as fuel does. Every motor has some blowby. So along with gasoline, you're also getting alky and some water past the rings. Normal engine bearings can't handle the water/alky in the oil. When that happens, it destroys the frosting on the bearings... thus the gray haze in the oil.

After amost every run, most alky racers will change the oil in their race cars(!). Again, that is much more of an extreeme example compared to our application.

So...
- How often did you change the oil in the car?
- Did it sit often?
- Do you have a functioning PCV system?
- Would you consider the ammount of alky you ran to be a LOT?


Regardless of where the bearing material (or whatever it is) is coming from, you said that it is plainly visable in the drain oil. No matter what you find (bad cam bearings, turbo, main/rod), I think you'll be pulling the bottom end appart. The pan could be dropped and a cap or two pulled to check the bearings... but I'd think that the material would already be impregnated into the soft surfaces of the bearing. Do it now and you might get away with minimal work. Wait and it will be worse.

Correct me if I'm wrong.

-Banning.

 

[GN SBS]

Interesting perspective-- thanks for the news.

*I change the oil very frequently; probably every 1 to 2 thousand miles. I've changed the oil after almost every trip to the track since I've had the alchy in given that I tend not to go more than bi-monthly.

*The car is not a daily driver and does usually sit during the week.

*PCV is functional.

*At a typical day at the track I may run through a full SMC bottle which I believe is 0.5 gallons. Since installing the alchy I've probably had 5 or 6 such days at the track. I'm not at WOT that much on the street so figure I've run 10 gallons through the car tops (which seems less than the amount of alchy I've bought, but I may be forgetting things).

I don't doubt that introducing alchy into the mix is tougher on the bearings; we do know that it doesn't take much coolant in the oil to foul the bearings. I don't have the knowledge to evaluate the machinists observation, but there are a bunch of folks who run alchy and race the cars a lot more than I do. I haven't done the research, but you'd expect to see a rash of bearing failures among users if the alchy was enough to cook the bearings in my case. On the other hand, maybe my bearings were on the edge and this took them over. At the very least, this is a very interesting angle to look into.

Others chime in!

-S.

 

[geno]

Originally posted by bruce
With a long screwdriver, try gently prying the crank back and forth.
If it goes more then a few thousandths, you've eaten the trust bearing. Usually it's obvious when too much is too much.
If you've had good oil pressure, that would be where I look first. [/QUOTE


This is what i would do (Just like Bruce said) and know in 5 minutes if the thrust is gone I really dont think the amount of alky used with our cars is enough to worry about. I use to pit on a sprint car and they have alot of these problems with alky in the oil also.. The 10 gallons you go through in ? mile is a far cry from the 10 gallon a sprint car goes through in one heat race Take the 5 minutes and check that thrust and im sure you will find it to be bad

 

[KWIKR 1]

Originally posted by bruce
With a long screwdriver, try gently prying the crank back and forth.
If it goes more then a few thousandths, you've eaten the trust bearing. Usually it's obvious when too much is too much.
If you've had good oil pressure, that would be where I look first.

yep, good idea . I wiped out a thrust and oil pressure was great even with it wiped !

 

[Black Demon]

Part deux

GN SBS...........I changed my oil yesterday and found the same exact thing as you. Engine has 7000 miles on complete rebuild and runs beautifully. 20 psi pressure at idle - 55 warm. Fine flakes in oil, took apart my filter and could see NOTHING with a spotlight. I tried to wrestle with the crank tonight, but I can't move it. Gonna have to drop the oil pan.


I have a PTS extreme convertor that I don't think has ballooned. Car has not been abused with only two trips to the track. Mainly used as a cruiser/show car. Any ideas on how these thrust bearings go bad? If bad machining, would it show up sooner than later?



I think I am going to be sick...........Wife is already on me about buying furniture. Looks like I have to get that 2nd job....How does it go? Would you like some fries with that ma'am

Keep me posted on your engine. I may look to buy a short block and drop it in rather than chase some gremlin in this engine.

Mike

 

[KWIKR 1]

Badly machined crank thrust face can act like a file or a wiper blade removing the oil wedge between the bearing thrust face and crank thrust face . or misligned cap or improper line bore can cause a problem as well . restricted/kinked oil cooler line can cause a high pressure condition pushing the converter into the crank . My last thrust lasted all of 30 mins in a newly rebuild engine . took engine apart and crank shaft thrust finish was VERY questionable (criss cross/hatchet pattern that could be picked up with your finger nail) along with a billet thrust cap machining issue . converter checked out ok along with trans cooler lines .and trans was fine before rebuild .

 

[turbotoyz]

been there done that!

had the exect same thing happond never noticed it till i blew the o ring out of my oil filter and found the golden flakes on my gurage floor and all over the bottom of the car. pulled the motor and did a very extensice tear down never found anything. preformed a rebuld with just polishing the crank and new cam and turbo. i suspected it might have been the turbo but have not been into it and could not see any major flake build it any where just in the pan. also i had a major KR problwem that i could not get rid of and the rebuild took care of it.



turbotoyz