no oil pressure

[JJ Daigle]

I have a 1990 ford ranger with a completly remanufactured 2.9L V6 most sensors have been changed all was well until I took it for its highway test the oil pressure droped off the map at about 40 to 45mph if I reduce my speed all is well like 20 to 30 mph any ideas?

 

[dvsj67]

This sounds scarey

So i know this is really basic.. but have you checked your oil level?

If you are sitting at idle.. does your oil pressure stay the same or does it fluctuate? what happens if you gradually increase the idle to higher RPMs? how does the oil pressure behave?

 

[JJ Daigle]

i hope my oil level is good, new engine and all.The oil pressure stays the same at an increased idle speed.The only time it will drop off is when its under a load othewise it doesnt fluctate at all

 

[dvsj67]

Well.. as silly as it sounds.. as a mechanic it wouldnt be the first tim ei have gotten "my truck wont start" and ask.. is there fuel? thats when i get the of course there is fuel and then BAM no fuel

Its not meant to be offensive we just all have our days.. its the tiny things that get over looked and lead to huge problems

Check the oil level, Did you rebuild the engine yourself? Do you know if the bearing clearances were properly checked? check to make sure the right oil filter is installed? Are you handy with diagnostics.. perhaps its a sending unit malfunction.

Usually the first thing that comes to mind with fluctuating oil pressure is that the clearances were measured incorrectly, or the oil level is low

 

[Sasquatch_Ryda]

Are you going off the gauge on the dash or an actual aftermarket mechanical gauge?

The factory gauge is nothing more than an on/off idiot light. It could be a simple as a bad sending unit.

 

[kimcrwbr1]

Sounds like a wiring issue to me unless the engine is overheating real bad. I was driving my cherokee over a pass when the oil light came on I noticed steam coming out from under the hood at 70 mph and loss in power my idiot light for temp was not working so it got so hot it lost oil pressure. All I can think of is a loose wire do all the other guages work correct or it may be getting too hot.