Engine has been running flawlessly. 158 k miles. Oil is clean and full.<br><br>Coming home tonight im coming up the drive way, slow in first gear. Just as I pull up to the house the check gages lite comes on and is binging at me......no oil pressure? I was already reaching for the key to shut it down, so ofcourse I did. I checked the oil....all is good. no oil on ground, full, clean etc....So I fire it back up.....for about 10 seconds...and no pil pressure.....? Currently the engine is / seems fine.<br><br>

 

Ok, I did a search, and feel better.....<br><br>On a 98 12 valve where is the sender? (One reply I read said under the ecm) 12 valve ecm....?<br><br>I did notice that I have a connector on the driver side near the filter that has two or three wires , its not plugged into anything, but was last week either when everything was fine....<br><br>If indeed oil pressure is a ok, what is the easy way to over ride the chime/ dash lights till I fix it?<br><br>

 

Do not start truck. First check oil pressure sender for a loose wire. I would also check engine falt codes. Next if you have a test pressure gage use port on oil filter base. Good Luck [undecided]

 

where is the sender and how do I check fault codes? I didn t think a 12 valve had engine fault codes?<br><br>

 

Check here for locations of sensors and such on a &quot;Under-Valved&quot; 12 Valve engine.<br><br>12 Valve Engine

 

Do not start the engine until you have checked out a few things. First as noted above, loctate and check the sender. Remove the wires going to it and check for corrosion, oil etc. Don't presume that just because they are tight that they are OK. Then if all that is OK install an oil pressure gauge at the port for the sender and fire it up. Watch the gauge closely and also listen for unusual mechananical noises. If any unusual mechanical noises are present then then shut down the motor after no more than 15 seconds running, specialy if there is no oil pressure. If you have good oil pressure then remove the temporary oil pressure setup and go back to the OEM setup. Start the motor again and watch the gauge closely. If still no oil pressure and it is dinging at you but the motor sounds fine then you have a choice. Drive it until you install a new sender (dangerous) or get a new sender right off the bat and start from there. Hope for your sake it is just a bad sender. Keep us posted on what you find.

 

As near as I can tell, that diagram in the link up there is wrong? It appears that my oil pressure sensor is right in front of the fuel heater, about an inch? Not 6 or so like the diagram shows.<br><br>I ll be checking it out today......more to come. <br><br>Hey what does it take to get the oil pressure sensor out? what size? any tricks?<br><br>I can barely get to it, or see it.<br>

 

I hooked up a mechanical gauge to the port on the top of the oil filter housing, all is good!!! pegged the 60 psi gauge at idle cold. <br><br>I screwed and screwed with the electrical connector on the oem sensor, and can not for the life of me get the clip off to unplug it....after an hour or so of doing that I checked the mechanical gauge, by starting it, and it has pressure on the mechanical gauge and now the oem DASH gauge is working again. I bought another oem sensor, 58 $ but can not get the connector unplugged to change it? BTW, my sensor is right in front of the fuel filter , maybe an inch....not further up on the block like a picture showed.<br><br>

 

Just for giggles does this look more like your engine?

22. Oil Pressure Sensor

 

The over all picture isn t even close (thats a 24 valve right?) but the location of the oil pressure swicth is correct!

Just for giggles, I noticed four other things wrong... I have a return spring off the throttle linkage up front, and can not find where the end of the spring hooks too?

Two, there is a spring near the oil pressure sensor connected to linkage that has a button head / clip end on it, and I can not figure out where it clips to, so the small spring is just hanging out there.

Three, I have a three wire male connector up top on the drivers side that when left laying there will just a bout touch the master cylinder, it s been unplugged since I got the truck, looks like a long long time, and I can t find a place that it would plug into?

Four, the end of the water in fuel sensor in the bottom of the fuel filter housing appears to be a female 2 prong plug that is not plugged in either? I can t find the other end for it either.

 

You sure someone didn't swap in a &quot;Powerstroke&quot; when you wern't looking........... <br><br>Reference material is quite often incorrect. :<br>As many time as I've seen that 12V pic posted, that's the 1st time I've heard anyone say &quot;That ain't right&quot;. <br>Congrats on picking up on something overlooked many, many times.<br>You've got sharp eyesight. ;D

 

I suspect its entirely correct for 94-97....I d bet 98's were changed due to the 24 valve introduction.....?<br><br>Any insight on any of the other stuff?<br><br>Electrical diagarm of engine?<br><br>

 

the first picture is a 12valve and the second is a 24v (notice how the valve cover(s) are different and the injection pump too. the throttle return springs hook onto the &quot;arm&quot; where the arrow for the &quot;oil pressure sensor&quot; is located. one on the back side, one on the side towards you. the other ends go on the throttle assembley (easy to see in that first pic). again, one in on the back side so it's a little harder to clip on. and in case you didn't notice, they slide on forward and backwards- they don't pop straight on and off. <br><br>otherwise, the losing oil pressure problem is somewhat common. i've had it happen on mine on some rare occasions. it's elsectrical- fairly common.<br><br>Tom

 

Whats strange is that my oil pressure sensor is in the 24 valve location but I have a 12 valve?<br><br>Is yours?<br><br>

 

Probably one of those &quot;transition&quot; engines.