Hey guys, This evening ( about 19 Fahrenheit) I went to start my 2000 cc V10 with 160,000 on it. The truck started normal and the oil pressure went up to about 3/4 (where its been since I got it). After about 30 seconds the gauge went from 3/4 to L then half then back to L and the red oil light came on, I immedatly shut the truck off. I started it again and still no pressure but no knocking, ticking etc then shut it off after 30 seconds or so about 30 min after I start it up again and its got the usual 3/4 pressure, drove around the block and let it get fully warm and I have no change in the engine or oil pressure Is it a faulty sending unit or a sign of oil pump in the near future Or a simple as a bad oil filter? since I got it a few days ago I changed the oil with mobil 1 5-30 and a FL820S filter and drove about 150 miles with no problems until tonight. The truck seems well maintained with dates and mileage scribbled on everything. When I got it the oil wasnt due for another 1,000 miles according to the sticker. Any ideas would be great. The reason I bought the truck was for the V10 being reliable!

 

Probably either a sending unit issue or an electrical issue.

They are not oil pressures "sensors", they are "switches". They just tell you if there's oil pressure but not how much, so in that vein they are a glorified idiot light.

They're cheap and easy to replace, I'd start there. When i remoted my OP switch to put in an actual gauge it did the same thing you just described. Turned out it wasn't properly grounded after I moved it. Once I grounded it again, it worked fine.

 

I had a issue almost like this with my car. By the time I looked up it was too late and I hit a phone pole. Dont try to drive and see if it works right. Oh, and it was a bad gauge.

 

I hope it's simple I can't afford to put an oil pump in right now but I turned the key on this morning and the guage flickered from half back to L with just the key on. Today after work I will check pressure with a mechanical guage and replace the switch. Does anyone know how much pressure they should be?