Disaster - thrown a con rod???

[alekos911]

There's a company I read about that does an analysis of the oil. From that they determine the cause of failure of the engine. Oil starvation would show lots of bearing shell in the oil, etc.

Might be worth looking into that.

I certainly rebuild the engine and not swap in an unknown one.

Thatis true cj. Also you can predict the failure of a certain component if you do this regularly.

 

[2alpsade]

There's a company I read about that does an analysis of the oil. From that they determine the cause of failure of the engine. Oil starvation would show lots of bearing shell in the oil, etc.

Might be worth looking into that.

I certainly rebuild the engine and not swap in an unknown one.

Thatis true cj. Also you can predict the failure of a certain component if you do this regularly.

Yes, the method uses Spectroscopy to determine the presence of trace materials in any given sample. Expensive to perform...we used it for long term analysis of turbine oils to assess material degradation, and it can be used to determine a failure mechanism/impending failure. Probably cost a good portion of an engine rebuild, though, so not really worthwhile in these 1-off situations as the results can still be argued over.

 

[bigdog]

There's a company I read about that does an analysis of the oil. From that they determine the cause of failure of the engine. Oil starvation would show lots of bearing shell in the oil, etc.

Might be worth looking into that.

I certainly rebuild the engine and not swap in an unknown one.

Thatis true cj. Also you can predict the failure of a certain component if you do this regularly.

Yes, the method uses Spectroscopy to determine the presence of trace materials in any given sample. Expensive to perform...we used it for long term analysis of turbine oils to assess material degradation, and it can be used to determine a failure mechanism/impending failure. Probably cost a good portion of an engine rebuild, though, so not really worthwhile in these 1-off situations as the results can still be argued over.

I used oil analysis at every oil change when I owned a trucking company. Cost £10 or $16 for each sample tested. Of course it's best when done from new. Even that is not a guarantee. As one could suffer a failure of the con rod bolt or some sort of microscopic metallic defect that fails suddenly.

 

[alekos911]

Yes, the method uses Spectroscopy to determine the presence of trace materials in any given sample. Expensive to perform...we used it for long term analysis of turbine oils to assess material degradation, and it can be used to determine a failure mechanism/impending failure. Probably cost a good portion of an engine rebuild, though, so not really worthwhile in these 1-off situations as the results can still be argued over.

Yeah that's exactly where I know it from. At my work we perform il analysis after each flight. Then we keep a data log so we can determine the trend of each material.

 

[Ewazix]

The last car I saw with a dropped con rod had been over filled with oil, small mistake, big bill.
I'm not sure how susceptible the BMW engines are to over filling but it's worth being clear about when, and who last changed or topped the oil.

 

[2alpsade]

Yeah that's exactly where I know it from. At my work we perform il analysis after each flight. Then we keep a data log so we can determine the trend of each material.

That would be an obvious use, of course It does seem that the costs of this have reduced considerably since I last enquired :roll: Long-term on any engine, these are nice tests to perform if you're a knowledge-geek, however, on an aero-engine they are essential! It's amazing just what these tests throw-up Now, whether they would find the cause of a mechanical failure in a car engine that's not had a baseline sample done, I'm not sure. There would be a lot of contaminants in there now, and difficult to predict what was there before the failure. The recent Alpina V8 engine failure I know of dropped its bottom end, the engine was returned to Buchloe and they could find no reason for failure. New engine supplied - they had never seen a failure of its type before; so a 1-off.

 

[cj10jeeper]

The last car I saw with a dropped con rod had been over filled with oil, small mistake, big bill.
I'm not sure how susceptible the BMW engines are to over filling but it's worth being clear about when, and who last changed or topped the oil.

Good point. I'm sure more engines are ruined by over than under filling as the latter is les obvious.
Has to be well I ee though to cause foaming and failure.

Assuming it wasnt being pushed hard at the time I'd be looking for a mechanical item like a disa flap dropped into the cylinder.