Chunk of piston ring found in engine oil
02-17-2012, 08:38 PM
#31
Drifting
My comment: "+1, it doesn't take much to clog an oil spray hole."
was in response to Makmov's "you just cannot account for all the tiniest pieces"
I didn't mean it had to be the actual ring chunk. If the spray holes are supplied with clean oil directly from the filter, then how do they ever clog?
was in response to Makmov's "you just cannot account for all the tiniest pieces"
I didn't mean it had to be the actual ring chunk. If the spray holes are supplied with clean oil directly from the filter, then how do they ever clog?
Last edited by Laker; 02-18-2012 at 10:52 PM. Reason: :D
02-17-2012, 09:37 PM
#32
Rennlist Member
I understand the oil flow of a air cooled 911, but according to Indy there is no way anything can get back into the engine because it has to pass the filter first, which I agree, looks fine on paper.
But who in their right mind would guarentee that?
The other question, unless I missed it, did this piece come from: the case or the tank?
There has to be some small ground up cylinder and piston material. No way the ring can get past without significant damage to those other componets, furthermore, at 85% leakdown it's got major issues. Even with only one ring on the piston in good shape it shouldn't leak that much.
But who in their right mind would guarentee that?
The other question, unless I missed it, did this piece come from: the case or the tank?
There has to be some small ground up cylinder and piston material. No way the ring can get past without significant damage to those other componets, furthermore, at 85% leakdown it's got major issues. Even with only one ring on the piston in good shape it shouldn't leak that much.
I work for a well known auto manufacturer. In my previous job assignment in an engine manufacturing plant I was in charge of analyzing engines that were returned from the field. On this particular engine architecture, the oil was circulated in the same way as a 911 engine. Say for example a rod bearing spun. The shrapnel from that failure would rip through the paper filter and wipe out the whole engine; main bearings rod bearings and cam bearings.
Saw a few broken rings and those destroyed the cylinder bore that they came out of.
So, in my experience, any loose metal traveling around in an engine was bad news. As for the engine that is the subject of this thread, it will be easy to do a progressive teardown and diagnose how much internal damage was done. However, as I stated earlier, if there is any fine aluminum particles in that oil all bets are off.
02-18-2012, 09:22 AM
#33
After coming back and reading your guys debate, there is a theroy. There is an oil bypass valve buit into modern day engines. I remember years ago (40's) there were no filters and then I remember when filters came out there was a bypass valve built into the filter housing and now the bypass valve is built into the filter. What the bypass valve does is to make sure the pressure will not exceed a predetermined amount. This can happen when fine material in high amounts clogs the filter. Now, weather larger media can then be entered into the system, I dont know. I just thought I would through this out there.
02-18-2012, 01:55 PM
#34
Nordschleife Master
mshobe , has the oil filter been opened up for a look see ?
Last edited by Indycam; 02-18-2012 at 02:11 PM.
02-18-2012, 02:38 PM
#35
Nordschleife Master
To big to have gotten past the filter . To big to have gotten past the oil pump .
02-18-2012, 02:50 PM
#36
Nordschleife Master
But getting a bit of a ring from the cylinder to the oil squirter is more than a little difficult .
02-18-2012, 03:00 PM
#37
Nordschleife Master
This trip called for flush-and-fill on the hydraulic pump and valve adjustment.
When they drained the oil to facilitate the valve work, they found a chunk of piston ring from a single piston in the drainage.
...and the car has run flawlessly since then. I didn't really notice the loss of power, but I also don't drive this car very often.
When they drained the oil to facilitate the valve work, they found a chunk of piston ring from a single piston in the drainage.
...and the car has run flawlessly since then. I didn't really notice the loss of power, but I also don't drive this car very often.
02-18-2012, 03:04 PM
#38
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You guys know all oil filters have bypass valves these days, right? It's quite common for them to be wide open during a cold start because the thick oil can't move through the media as easily as thin warm oil.
02-18-2012, 03:25 PM
#39
Nordschleife Master
02-18-2012, 04:03 PM
#40
Drifting
http://www.mahle.com/C12570B3006C0D4...JNLCY916STULEN
"A pressure relief valve guarantees the oil supply under all conditions – for viscous oil encountered during cold starts or at low temperatures, for extremely contaminated filter elements, or when the replacement intervals have been exceeded"
Come to think of it, I did actually know about the valve, as Arrowhead said but thought it only opened when the filter was totally clogged from over-extended use, which would never happen to anyone here....
Good call on the cold start FeralComprehension. Not saying this is what happened, we have no idea, just that it is possible.
"A pressure relief valve guarantees the oil supply under all conditions – for viscous oil encountered during cold starts or at low temperatures, for extremely contaminated filter elements, or when the replacement intervals have been exceeded"
Come to think of it, I did actually know about the valve, as Arrowhead said but thought it only opened when the filter was totally clogged from over-extended use, which would never happen to anyone here....
Good call on the cold start FeralComprehension. Not saying this is what happened, we have no idea, just that it is possible.
Last edited by Laker; 02-18-2012 at 10:51 PM.
02-18-2012, 07:19 PM
#41
I believe the bypass valve, well I know there is one in the motor itself, which means you don't need one in the filter. I am not sure if there is one in the filter or not, but there is also a t-stat in the houseing, I think it just might bypass the filter on cold starts.
That is all I was saying, too. There are all kinds of possiblities. Would I bet my life on anyone of them, No!
Furthermore, I still don't see Indy making any promises or guarentees.
Do whatever you need to do, but I stand behind my original comments.
And I don't know if you ever just broke a ring to break a ring on some white paper. They are very hard and brittle and you get some big peices, smaller, a tiny peices and some dust, which is cast iron with a moly coating - most likely.
There is no way to account for all the peices and particals.
That is all I was saying, too. There are all kinds of possiblities. Would I bet my life on anyone of them, No!
Furthermore, I still don't see Indy making any promises or guarentees.
Do whatever you need to do, but I stand behind my original comments.
And I don't know if you ever just broke a ring to break a ring on some white paper. They are very hard and brittle and you get some big peices, smaller, a tiny peices and some dust, which is cast iron with a moly coating - most likely.
There is no way to account for all the peices and particals.
02-18-2012, 07:27 PM
#42
Nordschleife Master
That says it can happen not that it is "quite common" . Its rare . If the oil gets near or below its pore point , until then the oil gets filtered in the normal manner . Its very bad for the valve to open up , everything is set up so that valve never opens up .
The Mobil 1 0/40 has a pour point of -47°C -53F
Brad Penn 20/50 has a pour point of -36C -33F
The Mobil 1 0/40 has a pour point of -47°C -53F
Brad Penn 20/50 has a pour point of -36C -33F
02-18-2012, 07:31 PM
#43
Nordschleife Master
Its this sort of statement that leads to my questioning you .
02-18-2012, 08:10 PM
#44
Makmov and Indycam are two of the most valuable guys here on the forum.
Hopefully this is just a hearty debate .. please make sure you dont get annoyed and never come back to the forum again
Hopefully this is just a hearty debate .. please make sure you dont get annoyed and never come back to the forum again
02-19-2012, 01:14 PM
#45
The two different valves do two different jobs . The one in the filter makes sure that the oil is not choked off from flow because of a plugged up filter . The valve in the case will "blow open" at a psi , that limits the psi . They do not do the same job .
Its this sort of statement that leads to my questioning you .
Its this sort of statement that leads to my questioning you .
I was always under the impression that there was one in the case or the filter, and you just need one and it was in one or the other place.
I was also under the impression there was a t-stat in the oil filter console. I could be wrong on that though.