Oil pressure reads low on OE gauge at turbo (Banks)

[whiteboyslo]

Hey all -

My OE oil pressure gauge has read low since....well, not sure. I've owned the truck for 1.5 years, and while I cannot definitively say it has always been low, it's certainly been low for quite some time. The gauge typically barely gets to the right of the the red line, let alone anywhere near 'NORMAL'. But, unplugging the unit DOES cause the gauge to zero out all the way to the left, so I know it's at least reading something. My truck has the Banks kit, so the sending unit has been relocated to the turbo just next to the supply line.

Today, I replaced the sending unit with a brand new Motorcraft unit, and if anything, the gauge now reads lower than before. FWIW the old one was about the diameter of a quarter and the body was about .75-1" in length. The new one is almost the diameter of a soda can and about 1.5" long.

The oil looks fine (black as tar, but what else is new?), and it doesn't consume a drop.

Any thoughts? And yes, an oil pressure gauge is likely on the Christmas list.

Mike

 

[79jasper]

Your oil "guage" is really a dummy system.
Once it hits 7psi, it pegs over.

You replaced the pressure switch with a real pressure sender.

Now you need to modify your cluster to work with it.

LOOK HERE
http://www.rowand.net/Shop/Tech/FordOilPressureGaugeFix.htm

 

[cowman79]

I had a problem with mine not reading consistently. I replaced the sender(switch) with a new one and still the same problem. I ended up cutting the end off the wire and replacing it with a ring terminal and tightened it down with two nuts on the sender and now my gauge reads properly. I have installed an aftermarket gauge to see the actual pressure but the gauge reading erratically bothered me.

 

[whiteboyslo]

Your oil "guage" is really a dummy system.
Once it hits 7psi, it pegs over.

You replaced the pressure switch with a real pressure sender.

Now you need to modify your cluster to work with it.

LOOK HERE
http://www.rowand.net/Shop/Tech/FordOilPressureGaugeFix.htm

If I replaced it with the OE part, is that what I really did?

Mike

 

[79jasper]

The books and computers will still show both and many more sensors that were probably never used.

I know for sure the one you put on has to be a real pressure sender. What's the P/N?

 

[whiteboyslo]

Motorcraft SW1547B. It's what RockAuto shows as the OE oil pressure sender/switch for my truck.

http://www.rockauto.com/catalog/moreinfo.php?pk=386505&cc=1124468

FWIW, the one that came off it looked almost exactly like this (also listed for my truck):

http://www.rockauto.com/catalog/moreinfo.php?pk=1005947&cc=1124468

Mike

 

[79jasper]

This link shows the different two sender's.
http://www.ford-trucks.com/forums/693315-curing-the-dummy-oil-pressure-gauge-3-0l.html

 

[hce]

I had a problem with mine not reading consistently. I replaced the sender(switch) with a new one and still the same problem. I ended up cutting the end off the wire and replacing it with a ring terminal and tightened it down with two nuts on the sender and now my gauge reads properly. I have installed an aftermarket gauge to see the actual pressure but the gauge reading erratically bothered me.

Same thing here, but use a wire tie to tighten up the pigtail connection.

 

[jaluhn83]

1) Get a real pressure gauge.

2) Take reading with the turbo connected at idle, then disconnect and plug the oil line at the turbo and try it again. Minimize the time (as in don't leave in running for minutes, 30-60 seconds should be fine) running and don't rev it up.

The pressure reading the second time should be a more accurate reading on what the main oil pressure is since the flow through the turbo and restriction of the small feed galley/elbow/hose will probably cause the oil pressure at the sensor to be somewhat lower than the actual line pressure.

Honestly as long as you've got ~10 psi hot idle and 20-30 at higher rpm you should be fine. These engines use high volume low pressure oil systems.