ALT-4 What to do when your Oil Light comes on
When the oil light comes on, there is not always a problem with the system. Most people confuse it with a bad oil pump. Actually it is an indication that there might be a low pressure situation in the engine's lubrication system. Here are the causes of the oil light to come on, and what you can do about them:
Low oil level.This would be the obvious first thing to check. Make sure there are no leaks, too. Especially at a front or rear main oil seal. If oil is coming out of either of these, the PCV system needs to be inspected for clogged hoes, or a sticking closed valve.
Engine idle speed not fast enough.If the engine is turning too slow, so is the oil pump. The oil pump only turns 1/2 the speed of the crankshaft, on most engines. If it is not turning fast enough, the system will never build up enough pressure to work properly. Check the IAC. Disconnect the vacuum hose from the brake booster, and see if the engine runs better and the light goes off.
Short in the wiring or gauge circuit.This is a very simple 'system'. There is a sender, one wire, and a guage. To test the system, make sure the wire isn't broken or shorted, by checking for continuity at both ends of the wire, and no continuity from the wire to a ground source (the car body). Continuity to a ground source will indicate a short in the wire. Continuity in the wire only will lead you to test the sender.
Faulty oil pressure sensor.Testing the sender is done by removing it from the engine and putting in a mechanical oil pressure guage. This is to test the system for an actual low pressure situation. If there is sufficient oil pressure, then the sender is bad. If there is a low pressure situation in the engine, that's not good.
Worn engine bearings and/or oil pump.If you had a low pressure reading on the gauge, then there is something wrong inside the engine. Basically, as long as the engine isn't knocking, ticking, or rattling, changing the oil pump will fix it.
But you have to realize that there are about 40 check valves in the lubrication system, and any one of them could be sticking open. That's why I recommend cleaning the system out. There is a chemical called Rislone that is an engine lubrication system cleaner. It will break loose the sludge, and help restore oil pressure caused from clogged oil gallery passages.
Now you know what to do when your oil pressure warning light comes on.
Thanks for reading!
