1991- Ranger 3.0L 155,000 miles

The oil idiot guage keeps showing that the pressure is really, really low. The oil level is OK and was just changed about 1000 miles ago. I'm using 10W30 with a motorcraft oil filter. This vehicle does not smoke or burn oil between changes. The engine does not click, tick, tap or knock.

This has been an ongoing thing. And i guess it just bugs me to see the needle pointing to the "N" on the word NORMAL. Sometimes it is barely that far up. Could the sending unit be bad or maybe have too much resistance because of a bad connection or loose wire? Where is the sending unit at? Thanks for any and all replies.

-hooD

 

Sounds like the sending switch to me.

'93 Ranger Manual says for the 3.0L:

"The oil pressure sending switch is located in the right rear face of cylinder block.

When installing, tighten to 20 N-m (15 ft-lb)."

 

Rockledge:

Would that be the passenger side of the engine? Will any oil leak out when the sending switch is removed? Do you know if this is a dealer part only or can it be bought at autozone?

-hooD

 

Yes, it is screwed into the block just behind the head on the passenger's side. When I changed mine, it was easier to get to it through the inner fender liner on the passenger's side. You will not loose any oil when you remove it.....Good luck!!

 

I saw what i think is the sending unit and man is it ever in a tight place to get at. Is it common for the sending unit to cause a LOW guage reading? I'd hate to replace the unit and still have a low reading.

\ NORMAL /
(My needle points between the \ and the N)

-hooD

 

UPDATE:

Bought a new oil pressure switch from auto parts store for $5.99 and a special socket for $2.99 made for removing the oil PSI switch. Replaced the switch and for the first time in years my gauge shows some respectable oil pressure again, even though it was always there the gauge read next to nothing. I'm a happy camper again!!!!

Had to jack the ranger up and remove the passenger tire to reach through the wheel well to get at the switch, but using the tapered socket was necessary to remove and install the switch. Listen to me blab on about my victory!!!
Thanks for the information guys!
-hooD

 

Nice job, thanks for the feedback.

 

For future reference to check the gauge all you need to do is ground the wire that connects to the sending unit and the gauge should read its highest reading if its working properly. just a little tip for checking before you buy a sending unit.

 

With the "idiot light" type of gauge, grounding the sending unit wire will just make the gauge read about half scale. It won't read max pressure, like a real
oil pressure gauge will.

 

Best bet is to install a real gauge.

 

Just changed the Oil Pressure Switch on my Mazda B3000 (3.0L Ford engine) 1994.
Oil pressure gague had been reading lower than normal for over a year now and caused me some concearn as to wether my oil pump was working or not.
Some Job! It took around 1 hr and 45 min. and great patience. Switch is located approximately at rear, top of engine, passenger side.
CONCLUSION: Removed right front tire and cut away some of the plastic of inner fender and got some light in there . Now, for the first time, could I see the sensor.
There is a wire harness of about 1/4 inch which is secured, with tape, to the engine block and interfears with access and view (this harness also provides the wire for the switch's connection). I freed the harness from it's anchor by carefully cutting away at the tape with a sharp blade and flashligh, ever so carefull not to cut the wires. (When the installation was finished I retied this harness to it's anchor with tie-wraps to keep it from touching the hot engine block)
NOW THE WORK BEGAN: The only thing I could get to work in this tight space, after trying everything I could think of, was a 7-1/2 inch Vise-Grip plier. I set the plier's jaws to the new Oil Pressure Switch's diameter so that, with great difficulty (resetting the plier jaws continually), to grab the old sensor and with ever so little bit, turned counter-clockwise. Eventually it loosened to where it could be turned by hand.
The old sensor's thread had a red substance (Lock Tite?) which made it so hard to turn.
Installed the new sensor with Blue Lock Tite, screwed it in by hand as far as could and then tightened with Vise Grip.
Finally I could read normal oil pressure in my gauge!