I get it that we are looking for Iron ppm as a wear indicator but what are the other main tipoffs when are trying to assess if a particular oil and OCI is protecting our engines. Thanks.
SF
SF
So what are the main wear indicators with UOA's
- Thread starter Snagglefoot
- Start date
- Status
A sudden change from one UOA to the next is really the only reliable clue. Everything else depends so much on engine type, details of internal configuration, materials used, etc. that the absolute numbers aren't much use. A big-block v8 with 4+ inch bores is probably going to have a higher iron percentage than a small bore 4-cylinder with a similar sized oil sump, even if the actual wear per millimeter of ring circumference is the same or even a little lower in the v8.
Unless there is some sudden high number, coolant or fuel dilution, i'm not sure how to gauge engine wear. I think of a uoa as a measure of how the oil is holding up and its basic components.
Last edited:
If you see copper or lead more than very low numbers (and have no oil cooler) then that is a good indication you have bearing that are wearing.
Baseline is good for iron. Also aluminum.
Baseline is good for iron. Also aluminum.
This makes me wish we had a sticky thread with links to all the bad UOAs posted to the site. I know they are out there but finding them may not be easy.
The ones I recall were:
Some guy with a newish motorcycle had some super high Aluminum or Copper numbers but he said the bike was OK.
One where it was very obvious that coolant was finding it's way into the oil.
For us motorcycle people, we also look at the cSt @ 100 value to see if the oil has sheared down past the original viscosity. I have one posted UOA showing where my Triumph sheared Rotella T6 5W40 to a 30wt in under 1k miles.
The ones I recall were:
Some guy with a newish motorcycle had some super high Aluminum or Copper numbers but he said the bike was OK.
One where it was very obvious that coolant was finding it's way into the oil.
For us motorcycle people, we also look at the cSt @ 100 value to see if the oil has sheared down past the original viscosity. I have one posted UOA showing where my Triumph sheared Rotella T6 5W40 to a 30wt in under 1k miles.
These types of UOA are more suited to determine the condition of the oil. For example, coolant, fuel, and dirt contamination. Showing engine wear, not much help there.
Originally Posted By: Donald
If you see copper or lead more than very low numbers (and have no oil cooler) then that is a good indication you have bearing that are wearing.
Baseline is good for iron. Also aluminum.
And if your engine bearings are into the copper, then most likely oil pressure will be dropping and the lower end will start becoming noisy.
Originally Posted By: Donald
If you see copper or lead more than very low numbers (and have no oil cooler) then that is a good indication you have bearing that are wearing.
Baseline is good for iron. Also aluminum.
And if your engine bearings are into the copper, then most likely oil pressure will be dropping and the lower end will start becoming noisy.
Look for trends and changes. Post you UOA here. Do some research. It's called fun.
Originally Posted By: Donald
If you see copper or lead more than very low numbers (and have no oil cooler) then that is a good indication you have bearing that are wearing.
Baseline is good for iron. Also aluminum.
Except for engines that don't even have copper or lead in the bearings. There are aluminum bearing engines out there with no copper or lead involved...
Quoting http://www.enginebuildermag.com/2012/10/getting-your-bearings/
"As most engine builders know, modern engines (late ’90s and newer) use bi-metal aluminum bearings, but each manufacturer has its own recipe for the construction and characteristics they are looking for. The basic construction is a steel back with a layer of silicone-aluminum facing the crankshaft."
If you see copper or lead more than very low numbers (and have no oil cooler) then that is a good indication you have bearing that are wearing.
Baseline is good for iron. Also aluminum.
Except for engines that don't even have copper or lead in the bearings. There are aluminum bearing engines out there with no copper or lead involved...
Quoting http://www.enginebuildermag.com/2012/10/getting-your-bearings/
"As most engine builders know, modern engines (late ’90s and newer) use bi-metal aluminum bearings, but each manufacturer has its own recipe for the construction and characteristics they are looking for. The basic construction is a steel back with a layer of silicone-aluminum facing the crankshaft."
- Status
Similar threads
