l researched this my self only after realizing l had to ad almost a half gallon of coolant. will the oil light come on if the car is overheating?
how would l know if coolant is mixed with oil? the oil looked clear a normal light brown color.
oh my gosh im sorry l did not realize l typed Lexus. l was thinking Lexus. l have a chrysler cirrus lxi. does this make a difference?

more then likely your oil pressure drops when you come to a stop, then you step on the gas your oil pressure goes up, also check your oil to make sure that your not low.

Sounds like the main bearings in the engine are worn.this is where your engine gets oil pressure.check the oil and see if it has coolant mixed with the oil? If so could be a cracked head..cracked block.blown head gasket..

you should not wait for an answer, take you car to a mechanic asap, is more safety.

yes take it to a merchanic and see whats wrong with it, also your engine may have a leak. It cost around 2-400 to fix a engine leak.

It could be as simple as the oil pressure switch. It is probably clogged. What year is ur Lexus? How many miles r on ur car? There is a sludge recall on 98-01 V6's. What happens is that the lack of oil changes causes sludge buildup in the engine. It clogs everything up, from consuming oil to possible engine lockup. The pickup screen gets clogged up with sludge & reduces oil pressure in the oiling system. Eventually leading to engine lockup.

To tell if you've got coolant mixed with oil, the oil will look milky. Take off ur front valve cover & see if there is any sludge in there. It will look like tar, if is it is bad enough, it will look like you've got brownies & chocolate syrup all over the inside of the valvetrain.

Your loss of coolant probably has nothing to do with the oil light. Leaking thermostat is pretty common on the V6's. Check all ur clamps & hoses. Check ur radiator. There is a hidden coolant bypass hose under the intake, that tends to leak too. A bad radiator cap would cause loss of coolant too. Blown head gaskets r worse case scenario. Take it to a shop & have them look at it. Have them perform a pressure test on ur cooling system for possible leaks. If ur car falls within the 98-01 year models, take it to Lexus, u might a free engine. At this point, the oil light is more of a concern than ur coolant loss. How often do u have to fill up coolant? Good Luck!