High Sodium in Oil Analysis ??? need advice
11-29-2002, 04:12 PM
#1
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High Sodium in Oil Analysis ??? need advice
I found some white sludge on the underside of my '86 951's oil filler cap. I have noticed a very slight amount amount of coolant loss, about two cups every oil change. Fearing that I have a coolant leak into the oil, I had an engine oil analysis performed.
As well, I did a cylinder leak down test a few days ago and had results on all 4 cylinders that ranged from 7-10%- that's good according to my gauge. I did a compression test at the same time that showed 150-155 psi on all cylinders.
Here are the results of the engine oil analysis and they confuse me a bit. Perhaps some experts on oil or coolant issues can help interpret what may be going on.
The report printout listed some test conclusions based on the sampled data below.
It indicated the following items as normal for the engine's age and mileage - 120,000:
Air filter, bearings, bushings, camshaft, crankshaft, cylinders, engine block, piston rings, pistons, wear metals, sludge potential, fuel content, water content.
It listed the following item as abnormal based on high sodium reading: Coolant content
Oddly, the test indictaed 0.0% water or glycol. I would expect if there was coolant present, some glycol would show in the test.
Any clever ideas about why the sodium could be showing up up? a thought on my end- Are the valves sodium alloy?
PPM Normal/Abnormal
Aluminum 31 N
Chromium 6 N
Copper 21 N
Iron 26 N
Lead 17 N
Potassium 18 N
Silicon 18 N
Sodium 65 A
%
Fuel 1.7 N
Glycol 0.0 N
Water 0.0 N
As well, I did a cylinder leak down test a few days ago and had results on all 4 cylinders that ranged from 7-10%- that's good according to my gauge. I did a compression test at the same time that showed 150-155 psi on all cylinders.
Here are the results of the engine oil analysis and they confuse me a bit. Perhaps some experts on oil or coolant issues can help interpret what may be going on.
The report printout listed some test conclusions based on the sampled data below.
It indicated the following items as normal for the engine's age and mileage - 120,000:
Air filter, bearings, bushings, camshaft, crankshaft, cylinders, engine block, piston rings, pistons, wear metals, sludge potential, fuel content, water content.
It listed the following item as abnormal based on high sodium reading: Coolant content
Oddly, the test indictaed 0.0% water or glycol. I would expect if there was coolant present, some glycol would show in the test.
Any clever ideas about why the sodium could be showing up up? a thought on my end- Are the valves sodium alloy?
PPM Normal/Abnormal
Aluminum 31 N
Chromium 6 N
Copper 21 N
Iron 26 N
Lead 17 N
Potassium 18 N
Silicon 18 N
Sodium 65 A
%
Fuel 1.7 N
Glycol 0.0 N
Water 0.0 N
11-29-2002, 08:48 PM
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Ah, almost afraid to mention this, but the analysis was done at JiffyLube. Not that I'd ever have them change the oil, but they do have a very slick computerized fluid analysis machine and even post the results online. I brought in a 2 oz. oil sample. They read the report, same as I did; no rocket scientists on staff. 
Funny thing, I had to show the operator how to calibrate the system with a built-in reference oil. The control UI for the analyzer is pretty self explanatory.
Funny thing, I had to show the operator how to calibrate the system with a built-in reference oil. The control UI for the analyzer is pretty self explanatory.
11-29-2002, 11:37 PM
#5
Nordschleife Master
Riiighhttt. That's great about helping him calibrate the machine.
Have you been eating a lot of potato chips in your car?
If it had come from your exhaust valves, you probably would have known about it before now. I understand they are sodium filled to improve heat transfer.
I think we need an expert for this one.
Have you been eating a lot of potato chips in your car?
If it had come from your exhaust valves, you probably would have known about it before now. I understand they are sodium filled to improve heat transfer.
I think we need an expert for this one.
11-30-2002, 05:13 AM
#6
Race Director
Sodium is typically part of an oil-additive package (along with zinc, molydenum, copper, phosphorus, etc.). Could also be part of ingested air near the ocean.
Depending upon when you took the oil-sample (after it's been sitting for a while, or right after a drive), water-content will vary. Water condensation in the crankcase is a byproduct of combusion. That's where the mist you see coming out the tailpipe at startup on cold days comes from. However, if you've been driving the car for a while at operating temperatures, all of the accumulated water will have boiled off.
I would monitor coolant levels to see if it's dropping to determine if a leaky headgasket is responsible for that sludge under the cap.
Here's a summary of oil-analysis results, not sure what it would indicate for your car though:
<a href="http://members.rennlist.com/oil/test_results.htm" target="_blank">http://members.rennlist.com/oil/test_results.htm</a>
Depending upon when you took the oil-sample (after it's been sitting for a while, or right after a drive), water-content will vary. Water condensation in the crankcase is a byproduct of combusion. That's where the mist you see coming out the tailpipe at startup on cold days comes from. However, if you've been driving the car for a while at operating temperatures, all of the accumulated water will have boiled off.
I would monitor coolant levels to see if it's dropping to determine if a leaky headgasket is responsible for that sludge under the cap.
Here's a summary of oil-analysis results, not sure what it would indicate for your car though:
<a href="http://members.rennlist.com/oil/test_results.htm" target="_blank">http://members.rennlist.com/oil/test_results.htm</a>
11-30-2002, 01:50 PM
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Danno,
Thanks for link to the oil analysis data. Quite a spectrum of vehicles and results.
I'll keep my eye on coolant consumption and do another analysis next oil change. For my test yesterday, I pulled some cold oil out of the dipstick tube with a big vacuum syringe. The car hasn't been seeing many miles lately due to work schedules. I assume if water were going to show up, it would have in yesterday's test.
I guess the upside is that there aren't significant enough contaminants to warrant some deeper issue.
I'm glad that both you and Travis thought that the sodium was related to an oil additive. I run Mobil 1, going to switch to a Castrol GTX on the reccomendation of Tim Benson at Fastlane. I'll do a test after that change as well to see if the sodium still shows up.
Thanks for link to the oil analysis data. Quite a spectrum of vehicles and results.
I'll keep my eye on coolant consumption and do another analysis next oil change. For my test yesterday, I pulled some cold oil out of the dipstick tube with a big vacuum syringe. The car hasn't been seeing many miles lately due to work schedules. I assume if water were going to show up, it would have in yesterday's test.
I guess the upside is that there aren't significant enough contaminants to warrant some deeper issue.
I'm glad that both you and Travis thought that the sodium was related to an oil additive. I run Mobil 1, going to switch to a Castrol GTX on the reccomendation of Tim Benson at Fastlane. I'll do a test after that change as well to see if the sodium still shows up.
