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How the OLM works.

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Old 11-13-2011, 07:47 PM   #1
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Default How the OLM works.

...GM engineer, Ms. Ellen Shirley Schwartz, PhD, is one of the researchers who developed the GM patent (#6,327,900 B1, dated 11-Dec-2001):


...the flow chart in Fig. 2 explains which parameters the OLM monitors and measures. Basically, there are three controlling parameters: the engine revolutions, the oil temperature, and the oil contamination:

• the oil "temperature (T) equation" used in the program is:

T(o) = k(2) + k(3)*S(e) + k(4)*T(c) + k(5)*F(q) - k(6)*T(a) ± k(7)*V(s)


S(e) = engine rotational speed, rpm
T(c) = coolant temperature, ºC
F(q) = fuel quantity, cubic-millimeters-per-cylinder
T(a) = air intake temperature, ºC
V(s) = vehicle speed, mph
k(2) = constant (-9.0 *)
k(3) = constant (0.012 *)
k(4) = constant (0.95 *)
k(5) = constant (0.21 *)
k(6) = constant (0.001 *)
k(7) = constant (0.01 *)

• the oil "contamination (C) equation" used in the program is:

C = k(8) + k(9)*I(t) + k(10)*F(q) + k(11)*T(o) + k(12)*S(e)


I(t) = fuel injection timing, degrees crank angle
F(q) = fuel injection quantity, cubic-millimeters-per-cylinder
T(o) = calculated oil temperature, ºC
S(e) = engine rotational speed, rpm
k(8) = constant (-2.7 *)
k(9) = constant (0.2 *)
k(10) = constant (0.03 *)
k(11) = constant (0.02 *)
k(12) = constant (0.001 *)

* = derived values for GM 6.6L V8 diesel test engine.

Thus, contrary to what Mr. Bob-the-Oil-Guy said, GM is actually tracking "calculated" oil contamination--not its ZDDP content--with the OLM...at least, as stated in their 2001 US Patent.
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Last edited by 70AARCUDA; 11-14-2011 at 06:02 PM.
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Old 11-14-2011, 09:42 PM   #2
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Awesome stuff CUDA
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Old 11-18-2011, 11:42 AM   #3
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The olm is resistant to long-term starvation, an adaptation to its underground habitat.I have the oil monitor also and it never seems to be consistent on the mileage.oil life monitor counts engine revolutions and accumulates the number for the basis of the oil life calculation.
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