Today i went out and drove for about 10-15 minutes at speeds above 50 before i began to park in front of Gamestop. While parking( it took a while because it was between to cars), the oil pressure light came on and then started blinking. Stopped when i shifted to drive after i backed up, then started blinking again. Didn't think nothing of it, left Gamestop then went to radioshack and noticed it blinking at a 3 way intersection, but stopped once i hit accelerator. Left Radioshack and headed home, hit a long redlight and it blink then staid on for about 10 seconds then blinked. agin took off and stopped. About a month after i got the truck it did this, and i checked the oil level, little low but not on add. Filled up and never did it again, checked oil a couple days ago, about a 1/4 inch above the add line, didn't add any because it wasn't low. Going to add some tommorow, what could be causing this? Just this small amount missing shouldn't cause the light should it? Oil changed 9/11/07, (odo broke, every 3 months) 1992 D150 5.2L V8. using penzoil high mileage, (odo says 217,XXX), 10W-40(listed in manual, should i use this or 30).

 

your oil pump is going out

 

Only way to tell for sure is to hook up a manual gauge and see how much oil pressure you actually have. If you have more than what the switch is supposed to turn on at then replace the switch. If the oil pressure is actually low, then the engine bearings are worn out and so much oil is leaking out between them that your pressure is dropping. If you don't have a manual gauge then just put a new sensor in it and see what happens...they are usually really cheap. If your pressure is actually low then I'd put a high volume oil pump in it soon to buy some time...but you'll need an engine rebuild eventually.

Derek

PS - if you actually have low oil pressure then 10W30 would be worse than 10w40.

 

Oil pressure sender may be bad...have you changed it?

 

I thought my oil change guy(don't have any place to dump used oil) was using 40, ended up being 30. I thought pump, haven't checked oil yet. Drove to school and it didn't so it at all. Tried to make it do it, idle at a stop for a while off road on a level concrete plate. Nothing, didn't come on at all. So i am thinking it is sensor for gauge, but where would that be?Does it look like this:. Or do i need to repalce the pump, the sensor would be cheaper than a pump. But like i said it doesn't seem to do it everyday all the time. You guys don't think it has anything to do with me driving at highways speed and then idiling for a while would it?

 

If you have a small block that sensor is back by the distributor.