Thanks again for the information! I love this forum. I have 5w-30 in there currently but may go to 5w-40 from reading some of the other posts.

 

In '86 it may be more than just a glorified idiot light. I know it was a REAL gauge in the vans until '92.

 

No light just the gauge in the instrument cluster. No actual psi indicated though on the gauge. Thanks.

 

I just put a SunPro 2" Styleline mechanical gauge in my 78. It fit real nice on the left side of the dash just above the headlight and wiper switches (if no a/c).
I got it on Amazon for $16. It works great for the nice price!

 

Oil is thick when cold/cool. As it warms up with engine it thins out, allowing it to flow easier through the engine. That is why an older engine will have less o.psi than a new one: the space between the bearings and mating surfaces has more space than a new engine b/c of wear, so the oil has less hindrance to its flow. Oil pressure measures the resistance to the oils flow.

That said, I would do what the previous members recommended, especially ck the oil p/u. You might want to think about using a thicker oil too. You could always pull the pan when all else fails, and ck the oil p/u and coupling gasket in the tube, and gasket at pump, and while you're there pop off one of the mains and one of the rod caps and plasti-gauge it. That will tell you the state of the engine bearings.

I had a similar problem with another engine. There are two oem openings in the lifter galley. One is where your psi sending unit is. The other is forward in a straight line toward the front of the engine, at the same height. You'll see an allen plug. If you put a gauge there you get a higher reading.

 

Thanks for the info on the other plug. I am not sure the wiring harness will reach it but maybe just the oil pressure wire out of the harness will. I already put a new pickup and oil pump on and so it has a new oil pan gasket also. I really do not want to pull that off again unless I do a complete rebuild which I may do anyway if things do not improve and the oil pressure tester tells me the pressure is lower than it is supposed to be. I haven't had a chance to hook it up and test it yet but maybe tonight and I will post the results on this thread.

 

With mine I just fashioned a funky bracket and mounted a cheapo manual gauge right on the block at that forward plug.

 

That is a great idea and that may be what I connect a gauge mounted in the cab to.

 

If the plug on the front gives you a higher pressure reading, that might make you feel better but Ford took the pressures from the back plug for some reason... I'm not wanting to start something, just my thought.

 

You are probably correct and I will see what happens at both points when I test the pressure and see if there is any difference. Thanks again!

 

Look at the sending unit. If it's little it's just a switch.If it's larger (1.5"-2" can) then you've got a 'pressure' gauge on the dash. If it's little (less than 1" can) it's just a switch, and you have a glorified idiot light in the dash. That is a gauge with a resistor wired into to so it shows 'NORMAL'.

 

My '91 has started doing this too - used to be when I was 5 minutes from home (60 min commute, mostly highway), now it does it 10-15 minutes of driving. I hear a tap while in the cab at idle, but if I go stand at the front of the motor the tap is not as pronounced - if it's the phantom I6-lifter tap, it's just one. I don't really notice any lack of power, tho - I would think if the oil pressure were really flatlining she'd be pretty bogged down. Truck went from quiet and smooth running to sounding like an old vacuum cleaner with a rough idle, so I suspect exhaust leak. It's all probably a bunch of little things that can add up to one big headache I'd like to avoid - but I can't afford the rebuild just yet. I'm currently at 173k, and due to smog at the end of October... *gulp*.