Oil analysis

[Victor R]

I wonder if anyone has experience with analyzing abnormal
patterns from an oil analysis. The engine in question is an
EJ25 that has elevated aluminum levels, about 5 to 6 times
normal, over the past two samples. The source of the aluminum
is possibly from the pistons.

Fuel contamination has risen to 2.5% this sample, while being
below 0.5% in previous samples. Viscosity is below recommended
averages. Everything else besides Al seems normal. The fuel
contamination is likely causing the lowered viscosity numbers.
The lab reports no coolant in the oil. The car is used mostly
for short trips of 5 miles or less, with occasional highway driving.

Any guesses what might be causing the elevated aluminum levels?
Suggestions for diagnosis also appreciated.

 

[1 Lucky Texan]

I wonder if anyone has experience with analyzing abnormal
patterns from an oil analysis.  The engine in question is an
EJ25 that has elevated aluminum levels, about 5 to 6 times
normal, over the past two samples.  The source of the aluminum
is possibly from the pistons.

Fuel contamination has risen to 2.5% this sample, while being
below 0.5% in previous samples.  Viscosity is below recommended
averages.  Everything else besides Al seems normal.  The fuel
contamination is likely causing the lowered viscosity numbers.
The lab reports no coolant in the oil.  The car is used mostly
for short trips of 5 miles or less, with occasional highway driving.

Any guesses what might be causing the elevated aluminum levels?
Suggestions for diagnosis also appreciated.

Definitely check the info/forums at bobistheoilguy.com .

My guess would piston skirt wear. Perhaps caused by ring or ring land
problems? Maybe wet/dry compression testing is in order?

Maybe an injector is failing 'open'? Also, very short trips could mean
the car is in 'choke' mode more. A failed Engine Temp Sensor (NOT the
coolant gauge sender) can keep a car in 'choke' mode - as if it never
warms up. Could lead to higher fuel use and perhaps contamination if
coupled with short trips (reduced opportunity to drive out volatiles).
I also wonder if a bad PCV Valve could somehow contribute to the
problem?

 

[weelliott]

I wonder if anyone has experience with analyzing abnormal
patterns from an oil analysis.  The engine in question is an
EJ25 that has elevated aluminum levels, about 5 to 6 times
normal, over the past two samples.  The source of the aluminum
is possibly from the pistons.

Fuel contamination has risen to 2.5% this sample, while being
below 0.5% in previous samples.  Viscosity is below recommended
averages.  Everything else besides Al seems normal.  The fuel
contamination is likely causing the lowered viscosity numbers.
The lab reports no coolant in the oil.  The car is used mostly
for short trips of 5 miles or less, with occasional highway driving.

Any guesses what might be causing the elevated aluminum levels?
Suggestions for diagnosis also appreciated.

I'm not oil expert, but will put in my two cents. That may be all this
si worth though...

You say that the deltas are in the last two samples as compared to
earlier ones. Were the last two samples of oil used in the winter,
whereas earlier ones were only collected in warmer months, then no
experience last winter? Like you perhaps just started this sampling a
year or so ago? If so, it might be seasonal differences. Cold weather
makes for harder starts, which causes more wear. Also, in cold
weather, fuel doesn't atomize as well, letting some of it condense on
the cold cylinder walls, then getting washed off into your oil while
the piston is above that area.

Total theory. I'd suggest looking into the possibility that this is
seasonal if you don't have previous winter experience to counter that.

Bill

 

[1 Lucky Texan]

I wonder if anyone has experience with analyzing abnormal
patterns from an oil analysis.  The engine in question is an
EJ25 that has elevated aluminum levels, about 5 to 6 times
normal, over the past two samples.  The source of the aluminum
is possibly from the pistons.

Fuel contamination has risen to 2.5% this sample, while being
below 0.5% in previous samples.  Viscosity is below recommended
averages.  Everything else besides Al seems normal.  The fuel
contamination is likely causing the lowered viscosity numbers.
The lab reports no coolant in the oil.  The car is used mostly
for short trips of 5 miles or less, with occasional highway driving.

Any guesses what might be causing the elevated aluminum levels?
Suggestions for diagnosis also appreciated.

Also, pulling the spark plugs, marking them with their cyl number, and
comparing side-by-side might point to which cylinder is the culprit -
if there IS only one.