Toyota Repair: 95 Camry, 4cyl, 198,000 miles, oil pressure sending unit, oil sludge

Question
When starting car, oil light comes on and stays on for about first 1-2 minutes of driving, then goes off. Happens only when starting but at any time of day or night. Thanks, appreciate your posting.

Answer
There are a couple of possibilities, one of them is that the oil pressure may just be too low after startup, the oil pressure can be checked with a pressure gauge attached to where the pressure switch is located, if the pressure reading is good( normally between 8-12 psi)at idle then it may just be a bad oil pressure sending unit, it's located on the cylinder head towards the front of the car. You may want to just try replacing it and see if it helps. Another reason may be that the engine has some oil sludge builtup which can restrict the flow of oil into the oilpump pickup screen in side the oil pan, a good indication of excessive sludge is to remove the valve cover and looking at the inside components, if they are clean with just some oil on them then there is not a problem with oil sludge but if there is then it becomes a more serious issue in which the oil pan should be removed to inspect the oil pump pickup screen, driving it in this condition may cause serious engine damage.