LS3 Engine Oil Sample -Thoughts?

[Reece Pettersen]

Check out the oil sample on my ls376/525. I am having a new engine built even though it isn't making a weird sound and leaks down. What would you do; replace or run? Think its main bearings going?  

 

[Grease Monkey]

Reece,

The sample shows 500 miles on this oil.  Questions I have.

1. Actual miles to the best guess.

2. Oil brand and weight. Never mind. I see Mobil 1 5w-30

3. Gasoline, race gas or E85.

4. Do you get the majority of the oil out with each oil change or is there oil left behind in an oil cooler, oil lines, oil pan etc.

5. The most important with oil samples is trending wear. A one off oil sample doesn't help with determining how bad this could be.  Its used all the time for pre purchase evaluations but comes with more questions when they come back like this.

There is usually some carry over in wear metals from the break in and build up in the oil pan can cause a false alarm.  Taking the oil sample from the drain plug isn't the ideal way. Proper oil sampling is from a scavenger hand pump, new nylon tube and taken from warmed up oil with the tube inserted into a dipstick tube from the oil at the half level area.  You want to take the sample with minerals in suspension and not from the oil pan bottom.

I am happy to comment on the results and where these minerals come from but if the sample is compromised by the technique taken to pull them then this may be all for nothing. 

BTW, I process and interpret 1000's of samples a year.

 

[Reece Pettersen]

Reece,

The sample shows 500 miles on this oil.  Questions I have.

1. Actual miles to the best guess.

2. Oil brand and weight. Never mind. I see Mobil 1 5w-30

3. Gasoline, race gas or E85.

4. Do you get the majority of the oil out with each oil change or is there oil left behind in an oil cooler, oil lines, oil pan etc.

5. The most important with oil samples is trending wear. A one off oil sample doesn't help with determining how bad this could be.  Its used all the time for pre purchase evaluations but comes with more questions when they come back like this.

There is usually some carry over in wear metals from the break in and build up in the oil pan can cause a false alarm.  Taking the oil sample from the drain plug isn't the ideal way. Proper oil sampling is from a scavenger hand pump, new nylon tube and taken from warmed up oil with the tube inserted into a dipstick tube from the oil at the half level area.  You want to take the sample with minerals in suspension and not from the oil pan bottom.

I am happy to comment on the results and where these minerals come from but if the sample is compromised by the technique taken to pull them then this may be all for nothing. 

BTW, I process and interpret 1000's of samples a year.

1) probably ~7.5k off road miles

2) N/A

3) 91 octane

4) there is left over in the coolers, but many oil changes since new 

5) noted

I sampled the oil from the drain plug when changing the oil. This motor has been run hard, so I assumed the worse case scenario. If the levels were high, but not so dramatic, then I wouldn't have worried about it. 

I appreciate the help! 

 

[Grease Monkey]

The oil is tested at 100 deg C. This translates to roughly 235 deg F which is average oil operating temperature. Its what all the labs test at and where they derive the viscosity of the oil. Your oil is showing 8.6 weight at operating temperature.  Due to the slight fuel dilution, this is coming in a bit low. I would expect under normal operation to see a 5w-30 to come in around 11-12 weight at OP temp.

Looking at the wear materials and seeing the higher silicone makes me wonder if dirt/sand is getting past the air filter.   The soot level is low to non existent so I doubt you are seeing any elevated crankcase pressure. Soot would be from compression passing the rings and fouling the oil with carbon.

The copper is creeping up and will follow the lead. As the lead wears off the bearings, it will expose more copper.  Sign that the bearings are wearing or soon to be worn.  How has the oil pressure been at op temp? Any lower than when the engine was new?

The iron (cylinders), chrome (rings) and the aluminum are elevated.  This is all cylinder related.  They go hand in hand when things start to wear out or scuff.  Assuming no elevated crankcase pressure, I would change the oil and take another sample at the 500 mile mark. Lets see if things are progressing.

I can set you up with the correct tooling and oil sample kits. 

For that matter. Anyone else reading. Let me know.

IMO, the sample isn't pretty but its not a death sentence.  If you choose to use the sample as a monitoring devise, I'd say go for it and run it, but, start taking the samples correctly, at the same intervals and with the same oils.

Ill say it again. Taking a sample from the drain plug can provide unsatisfactory results.  In the end its your $$$, your mindset and ultimately your comfort level in running more or diving into the engine.  You know your car, engine and driving habits. 

One thing that keeps me going is the ever changing oil companies and the additive packages being used. EPA has forced oil companies to remove many of the good minerals and substituted with others to provide thickening properties and anti wear properties that were never used in the past.  The lab you use for this sample does a good job in categorizing these as "multi source metals and additive metals"  

 

[EastMT]

@Grease Monkey How many hours of use for a sandcar would you suggest for test intervals for a n/a unleaded engine?

 

[Grease Monkey]

@Grease Monkey How many hours of use for a sandcar would you suggest for test intervals for a n/a unleaded engine?

One a new or rebuilt engine I would wait 500 miles or 100 hours. This lets the rings seat and the cylinders wear in.  Then I would oil sample at 500 miles.  This is on a basic run of the mill naturally aspirated engine.  Outside of that its the wild west.  Most engine builders are asking owners to change oil after a healthy week in the dunes on Turbo and supercharged race gas and E85 fueled engines.  Personally I sample at 500 miles on a Turbo E85 subi. 

 

[Reece Pettersen]

@Grease Monkey this is some really good information. Thank you! Makes me think I should keep running the engine since I might have elevated readings due to sampling from the drain plug. 

I have been struggling with dirty oil after minimal off road miles and still can't figure it out. I run dual UMP filters and the intake/throttle body is always clean with no signs of passing dust when I change the oil. However, the oil looks like it is very contaminated and dirty. Thought it might be a leak in the intake manifold, but that would cause high idle and show up on the dyno. 

 

[Grease Monkey]

@Grease Monkey this is some really good information. Thank you! Makes me think I should keep running the engine since I might have elevated readings due to sampling from the drain plug. 

I have been struggling with dirty oil after minimal off road miles and still can't figure it out. I run dual UMP filters and the intake/throttle body is always clean with no signs of passing dust when I change the oil. However, the oil looks like it is very contaminated and dirty. Thought it might be a leak in the intake manifold, but that would cause high idle and show up on the dyno. 

View attachment 109513

The oil is doing its job.  Mobil 1 has shown to be a good oil.  This isnt a highway cruiser.

 

[lincster]

One a new or rebuilt engine I would wait 500 miles or 100 hours. This lets the rings seat and the cylinders wear in.  Then I would oil sample at 500 miles.  This is on a basic run of the mill naturally aspirated engine.  Outside of that its the wild west.  Most engine builders are asking owners to change oil after a healthy week in the dunes on Turbo and supercharged race gas and E85 fueled engines.  Personally I sample at 500 miles on a Turbo E85 subi. 

CBM recommends changing oil in boosted motors after every dune trip.

I change mine every other dune trip and clean air filters every trip.

No oil analysis to back anything up, just what I've always done.

 

[1HasBeen]

I have always sampled at the drain plug, but wipe/blow with compressed air around the plug before removal, and then sample "mid-stream". Is this incorrect?

 

[ChasingSand]

CBM recommends changing oil in boosted motors after every dune trip.

I change mine every other dune trip and clean air filters every trip.

No oil analysis to back anything up, just what I've always done.

Same here. Boosted and on E85, change every trip. Cheap insurance.

 

[Sandkist]

I have always sampled at the drain plug, but wipe/blow with compressed air around the plug before removal, and then sample "mid-stream". Is this incorrect?

Mid stream sampling is fine. Different labs give slightly different sampling procedures. The lab I use tells me to not start the engine immediately prior to taking the sample.

 

[Grease Monkey]

I have always sampled at the drain plug, but wipe/blow with compressed air around the plug before removal, and then sample "mid-stream". Is this incorrect?

Mid stream sampling is fine. Different labs give slightly different sampling procedures. The lab I use tells me to not start the engine immediately prior to taking the sample.

Bottom sediment, debris and particles (including water) enter the bottle in concentrations that are not representative of what is experienced near or around the area where the oil lubricates the machine components.

Not ideal but if you are using these samples to trend wear and you can repeat the process every time with the same hours/miles, this can be used to trend wear. Unfortunately as in Reece's case, this may lead to a false positive for elevated wear minerals/materials. 

 

[Sandkist]

Bottom sediment, debris and particles (including water) enter the bottle in concentrations that are not representative of what is experienced near or around the area where the oil lubricates the machine components.

Not ideal but if you are using these samples to trend wear and you can repeat the process every time with the same hours/miles, this can be used to trend wear. Unfortunately as in Reece's case, this may lead to a false positive for elevated wear minerals/materials. 

One would think that sampling through the dipstick tube at mid pan oil level is the most accurate. The lab I use feels that both sampling methods are suitable with little to no difference in test results between the two. Maybe I need to change labs  :classic_biggrin:

 

[Grease Monkey]

One would think that sampling through the dipstick tube at mid pan oil level is the most accurate. The lab I use feels that both sampling methods are suitable with little to no difference in test results between the two. Maybe I need to change labs  :classic_biggrin:

The best sample method is from a ported fitting pre filter from the running machinery.  This would sample the oil at operating temp and from fluid that is lubricating the machinery.  One thing to focus on is AT operating temp.

Oil at operating temp (235-240 deg F) will have steamed off any water in the oil that could have been introduced thru cool down condensation.

 

[J Alper]

These motors are way over fuled,  the oil needs to be changed ever trip,  

Also Factory motors use cheap bearings solid aluminum,  so is the lead coming from the fuel,  or did someone rebuild this motor with a HP, bearing ,  or a P bearing, 

Its not as simple as the main bearing going,  can be a rod bearing,  who built the motor,  we do a full build list on our motors,  

Very little info on the motor,  

is it completely stock from GM,  what is the bearing clearance set at,  oil V, depends on clearance,  

 

[Bobalos]

One would think that sampling through the dipstick tube at mid pan oil level is the most accurate. The lab I use feels that both sampling methods are suitable with little to no difference in test results between the two. Maybe I need to change labs  :classic_biggrin:

I know it would double the cost, but.... maybe do both 3 or 4 times and review the results.  It could be beneficial for the rest of us.  LOL 

 

[FOG]

Really good information in this thread.
Thanks @Grease Monkey for sharing your expertise.