Oil Level Above Max
12-13-2014, 07:04 PM
#31
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Had my engine oil changed on Monday, and all green. By Friday the yellow light came on and has been on for 200 miles. I ordered the vacuum syringe Sam posted. Murphy's Law says that the day the syringe comes, the yellow light will go out! I still can't figure out why the light would come on 4 days later after it is was measuring normal max green? Expansion?
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12-13-2014, 08:00 PM
#32
Burning Brakes
One would have thought the dealer would allow for expansion....but
I'm a dummy to believe that!
12-13-2014, 08:43 PM
#33
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I don't see how heat expansion can account for the difference. You would not have been able to get the first reading until the oil had warmed up to about 190 F. Same for the second reading. There would be no major temperature difference.
That being said, a yellow reading should not be of major concern.
That being said, a yellow reading should not be of major concern.
12-13-2014, 08:48 PM
#34
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I don't see how heat expansion can account for the difference. You would not have been able to get the first reading until the oil had warmed up to about 190 F. Same for the second reading. There would be no major temperature difference. That being said, a yellow reading should not be of major concern.
I remember seeing this equation this summer:
Specific volume of a unit can be expressed as
The change in the units volume when temperature change can be expressed as
dV = V0 β (t1 - t0) (2)
v = 1 / ρ = V / m (1)
where
v = specific volume (m3/kg)
ρ = density (kg/m3)
V = volume of unit (m3)
m = mass of unit (kg)
The density of a fluid when the temperature is changed can be expressed as
where
dV = V1 - V0 = change in volume (m3)
β = volumetric temperature expansion coefficient (m3/m3 oC)
t1 = final temperature (oC)
t0 = initial temperature (oC)
ρ1 = m / V0 (1 + β (t1 - t0))
= ρ0 / (1 + β (t1 - t0)) (3)
where
ρ1 = final density (kg/m3)
ρ0 = initial density (kg/m3)
Volumetric Temperature Coefficients - β - of some common Fluids •water : 0.000214 (1/oC),
•ethyl alcohol : 0.00109 (1/ oC), 0.00061 (1/oF)
•oil : 0.00070 (1/oC), 0.00039 (1/oF)
Hot engine ~220F and room temp ~75F and that's 145F temp difference. The oil volume expansion is then 0.00039 * 145 = 5.6%
5.6% of 9L of oil = 0.5L
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Last edited by LexVan; 12-13-2014 at 09:09 PM.
12-13-2014, 09:20 PM
#36
Race Director
I understand that (and BTW I liked your analysis proving the issue of expansion) but regardless I didn't like having that message come up after my oil change. Low tolerance for yellow warning lights, apparently. So I drained about 3/4 pint and was happy as a clam with my optimum 3 bars. It's hell being ****....
12-13-2014, 09:59 PM
#37
Three Wheelin'
Max expansion starts to happen above the 210-215 mark.
I remember seeing this equation this summer:
Specific volume of a unit can be expressed as
The change in the units volume when temperature change can be expressed as
dV = V0 β (t1 - t0) (2)
v = 1 / ρ = V / m (1)
where
v = specific volume (m3/kg)
ρ = density (kg/m3)
V = volume of unit (m3)
m = mass of unit (kg)
The density of a fluid when the temperature is changed can be expressed as
where
dV = V1 - V0 = change in volume (m3)
β = volumetric temperature expansion coefficient (m3/m3 oC)
t1 = final temperature (oC)
t0 = initial temperature (oC)
ρ1 = m / V0 (1 + β (t1 - t0))
= ρ0 / (1 + β (t1 - t0)) (3)
where
ρ1 = final density (kg/m3)
ρ0 = initial density (kg/m3)
Volumetric Temperature Coefficients - β - of some common Fluids •water : 0.000214 (1/oC),
•ethyl alcohol : 0.00109 (1/ oC), 0.00061 (1/oF)
•oil : 0.00070 (1/oC), 0.00039 (1/oF)
Hot engine ~220F and room temp ~75F and that's 145F temp difference. The oil volume expansion is then 0.00039 * 145 = 5.6%
5.6% of 9L of oil = 0.5L
Sent from my iPhone using Rennlist
I remember seeing this equation this summer:
Specific volume of a unit can be expressed as
The change in the units volume when temperature change can be expressed as
dV = V0 β (t1 - t0) (2)
v = 1 / ρ = V / m (1)
where
v = specific volume (m3/kg)
ρ = density (kg/m3)
V = volume of unit (m3)
m = mass of unit (kg)
The density of a fluid when the temperature is changed can be expressed as
where
dV = V1 - V0 = change in volume (m3)
β = volumetric temperature expansion coefficient (m3/m3 oC)
t1 = final temperature (oC)
t0 = initial temperature (oC)
ρ1 = m / V0 (1 + β (t1 - t0))
= ρ0 / (1 + β (t1 - t0)) (3)
where
ρ1 = final density (kg/m3)
ρ0 = initial density (kg/m3)
Volumetric Temperature Coefficients - β - of some common Fluids •water : 0.000214 (1/oC),
•ethyl alcohol : 0.00109 (1/ oC), 0.00061 (1/oF)
•oil : 0.00070 (1/oC), 0.00039 (1/oF)
Hot engine ~220F and room temp ~75F and that's 145F temp difference. The oil volume expansion is then 0.00039 * 145 = 5.6%
5.6% of 9L of oil = 0.5L
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I must have not been paying attention in college?
12-13-2014, 11:07 PM
#38
Rennlist Member
My car, delivered 12/5, indicated 3 bars on the oil gauge when I got home from the dealer. Today after 275 mi. the gauge still shows 3 bars.
12-13-2014, 11:28 PM
#39
Three Wheelin'
12-14-2014, 01:47 AM
#40
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My point is that there probably wasn't much difference in oil temperature between the two readings. swivelhi couldn't have taken a reading at 75F. It had to be a minimum of 190F. He said he took the second reading "after a nice drive". I tracked my GT3 very hard this summer and don't think that I ever hit 220F. So in the best case it could have been a 30F difference. Probably less.
At 30F the expansion would be 0.00039 * 30 * 9L = 0.1L
Your equation does a great job of explaining why the oil must be hot before you can take a reading (thanks!), but I don't think that it explains swivelhi's readings.
Last edited by IvanBurns; 12-14-2014 at 01:48 AM. Reason: typo
12-14-2014, 09:21 AM
#41
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I have several degrees in engineering and know that fluids expand with temperature. I'm sure that your equation is spot on.
My point is that there probably wasn't much difference in oil temperature between the two readings. swivelhi couldn't have taken a reading at 75F. It had to be a minimum of 190F. He said he took the second reading "after a nice drive". I tracked my GT3 very hard this summer and don't think that I ever hit 220F. So in the best case it could have been a 30F difference. Probably less.
At 30F the expansion would be 0.00039 * 30 * 9L = 0.1L
Your equation does a great job of explaining why the oil must be hot before you can take a reading (thanks!), but I don't think that it explains swivelhi's readings.
My point is that there probably wasn't much difference in oil temperature between the two readings. swivelhi couldn't have taken a reading at 75F. It had to be a minimum of 190F. He said he took the second reading "after a nice drive". I tracked my GT3 very hard this summer and don't think that I ever hit 220F. So in the best case it could have been a 30F difference. Probably less.
At 30F the expansion would be 0.00039 * 30 * 9L = 0.1L
Your equation does a great job of explaining why the oil must be hot before you can take a reading (thanks!), but I don't think that it explains swivelhi's readings.
12-14-2014, 10:19 AM
#42
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We can start analyzing the system down to a T. But I truly wont worry and wont trust the measurements and wont stop driving unless i get the red dont drive/dont touch/dont even dare look at the car warning on the screen. Reason being, my gauge reading with in a few hrs goes from four green bars then to a single then to 3........u get my point......fluctuates all over the place.
12-14-2014, 10:53 AM
#43
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The general conclusion was that the reading mechanism design involves some black voodoo magic.
12-14-2014, 01:47 PM
#44
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My guess is that there will some sort of upgrade to the electronics. In the meantime I will put a small 200cc bottle of oil in the frunk along with my quart. I find it hard to judge when I've hit something as small as 200cc when pouring from a quart bottle.
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