Oil Pump or?

[gwhilikerz]

The oil light on my 02 Merc Sable has popped up all of a sudden. The light comes on when I come to a stop and the rpm's go down. It flickers, then goes off when the rpm's pick up. The dipstick shows full. The car is parked right now. My question is: Do you think it is ok to drive to it to get the repairs or tow? I'm getting too old to drop oil pans and all that stuff.

[Quietgentleman]

First I would actually find out if the oil pressure is really dropping. I would take the sensor out and install a pressure gauge and see what kinda pressure it has at idle with the car in gear. Or you could just replace the oil pressure sensing unit and see if that doesn't fix your problem. As far as driving it to be repaired you can as long as you don't let it idle to long with out oil pressure. If you're sitting at a stop light just bump the car into neutral and speed the engine up enough to turn the light out.


QGM

[Prairie]

Since it comes on when you are idling hot in gear, I'd say it is most likely low oil pressure. It could be the oil pump, bad bearings, or simply a plugged oil filter. When did you replace the filter last?

[johnny]

Okay--omitted here is which engine is it--3.0--3.8--or?
How many miles? Has it had proper maintenance in the oil change department?
Humor me on this note but--unhook the battery cables and for whatever the reason--since off then hey--why not just clean and oil them up prior to re-installing--okay?
Now--light the booger up and check it out--if the light stays off then it was simply an electronic malfunction perhaps. It Happens. My 90 Ranger with the 2.9 V6 always showed low oil pressure on its gage from about 100K on. Put a new direct reading gage on it and voila--40PSI. This after having replaced the sensor a couple times. The gages and lights on them older ones were sort of a nuisance--not a prob but a pain in the old keester if one relied on them much. Auto parts stores sell a good gage for about 20 bucks and has a mounting bracket included so put your mind at ease if its gage or light prob--install or have one installed.
2.9--3.0 engines are usually good for around 200K if maintained properly. Dont know much about the 3.8 or the 4.0 ones but have heard good reports on them too so odds are--you have a faulty light or sensor or even a speck of dirt in the line leading into your sensor or oil pressure sending unit.
Also check your engines idle speed. If low or not good then check out the idle control valve--easy to replace and not expensive at about 40-45 bucks. Most have 3 screws and a hose or two--as said--easy fix! Yours probably should be in the 750-850 RPM range I believe and if not then the electronics can pick up on that and give false readings.
Rarely do the engines go on those and its usually the trannys that go first while the engine is purring nicely.