Wearing on a sleeved block? - audi s4

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81
Location
Virginia
So I sent off my first UOA to blackstone today and Im awaiting to see how the M1 Ow40 fares... I think it should be just fine. However, the scary part about my engine (2007 audi s4) is that the block is sleeved with Alusil (aluminum x 80% and silicon by 20 I think). Scored cylinder walls from wear on a alusil block are pretty much a done deal on that engine. Would a UOA show higher levels of aluminum/silicon if I had wall scoring in this engine?
 
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9,783
Location
Saskatoon canada
Originally Posted By: Guitarmageddon
So I sent off my first UOA to blackstone today and Im awaiting to see how the M1 Ow40 fares... I think it should be just fine. However, the scary part about my engine (2007 audi s4) is that the block is sleeved with Alusil (aluminum x 80% and silicon by 20 I think). Scored cylinder walls from wear on a alusil block are pretty much a done deal on that engine. Would a UOA show higher levels of aluminum/silicon if I had wall scoring in this engine?
Every engine wears differently. That being said a uoa is in now way an accurate way to measure wear. You have to establish trends. Once trends are established is an anomaly presents itself then it's a possibility that there is a problem,or could be a particle streak. A uoa is meant to monitor the condition of the oil. That's it.
 
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5,112
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Airlie Beach Australia
Hi, Guitarmageddon - Many German engines have Alusil blocks - Porsche for example. I had a number of these over time and they are very hard wearing Scored cylinder walls always have a cause - rarely if ever are they a result of the material they are made from Typically they will not show unusual aluminium or silicon wear patterns
 
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2,943
Location
Georgia/Retired
As Doug states, "Alusil" blocks have been used extensively over the years. I personally feel that more frequent oil changes are a proactive measure to longevity for these designs as opposed to a manufacturer recommended '10,000 mile' interval. Being a hypereutectic alloy, you might see elevated levels of silicon and copper with lower levels of phosphorus, calcium and even magnesium if there is abrasive wear taking place. Keep in mind that pistons have been made in this manner for ages and trend wear analysis is the most effective manner of keeping an eye on things. You won't see high levels of aluminum/silcon in an analysis simply because the block is made of a hypereutectic alloy.
 
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512
Location
USA
You are making the argument for doing oil analysis at every change. Once you can see what your engines' typical wear metals are at drain time you will then be able to see any unusual changes. Without the history you have nothing to compare your results to. I once worked for a shop where we only took samples of engine oil when the engine blew up. Surprisingly, the analysis showed... ...the engine had blown up. The shop manager was an idiot.
 
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335
Location
Maryland
Originally Posted By: AITG
I once worked for a shop where we only took samples of engine oil when the engine blew up. Surprisingly, the analysis showed... ...the engine had blown up.
Could you provide more details here? Without manager's blood and other tests, of course ;-) I mean how did you recognize engine failure just looking on UOA?
 
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512
Location
USA
Originally Posted By: timeau
Originally Posted By: AITG
I once worked for a shop where we only took samples of engine oil when the engine blew up. Surprisingly, the analysis showed... ...the engine had blown up.
Could you provide more details here? Without manager's blood and other tests, of course ;-) I mean how did you recognize engine failure just looking on UOA?
Huge amounts of Al, Cu and Pb. Goes nicely with the spun bearing. Or coolant in oil on a blown head gasket. In other words, the engine was in the shop for disassembly. Visual inspection agreed with oil analysis. "Yup, its blowed up"
 
Messages
512
Location
USA
Originally Posted By: AITG
Originally Posted By: timeau
Originally Posted By: AITG
I once worked for a shop where we only took samples of engine oil when the engine blew up. Surprisingly, the analysis showed... ...the engine had blown up.
Could you provide more details here? Without manager's blood and other tests, of course ;-) I mean how did you recognize engine failure just looking on UOA?
Huge amounts of Al, Cu and Pb. Goes nicely with the spun bearing. Or coolant in oil on a blown head gasket. In other words, the engine was in the shop for disassembly. Visual inspection agreed with oil analysis. "Yup, its blowed up"
Answering your question differently, we diagnosed the blown condition by such things as a dead miss while cranking, dipstick 3 gallons over full, oil a light beige and the consistency of cottage cheese, oil blowing out the exhaust (liquid, not just smoke). You know, your basic "blowed up".
 
Messages
335
Location
Maryland
Originally Posted By: AITG
Answering your question differently, we diagnosed the blown condition by such things as a dead miss while cranking, dipstick 3 gallons over full, oil a light beige and the consistency of cottage cheese, oil blowing out the exhaust (liquid, not just smoke). You know, your basic "blowed up".
Exactly! It does not make sense to have UOA done in this particular case, everything is clear. But would you recognize that camshaft is in this condition by just looking on UOA? http://ic.pics.livejournal.com/bmwservice/44166753/34071/34071_original.jpg
 
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