OIL Guage??

[Tekeman]

OIL GAUGE

My oil pressure gauge bounces when i'm idling with a warmed up engine. I added some oil but it didn't help. With just a few more rpm's than idle it goes away and is not seen while driving. Might this be the signs or an oil pump going bad? Maybe something else. Ever since Ford's OBDII? recall work the truck just hasn't seemed right.

 

[blk mk8]

it is only a dummy gauge so if it is jumpie then some thing is wrong with the sender. it should either be in the middle or at zero. i belive there is a way to make it work as a real gauge. i saw a post on the corral saying that there was hole Thread telling how to covert every thing to work right but i dont know where it is.

 

[Tekeman]

The gauge is oil pressure not oil temp. right? But couldn't something cause weak oil pressure? I'm not sure that I believe it's either 0 pressure or perfect pressure.

 

[IAMCDN]

What he meant is that the oil pressure guage is not really monitoring it like you would think. It is a on/off kind of thing, not a true pressure guage, or so I have been led to believe.

 

[Stephen S]

These guys are right, the oil pressure guage acts like an oil light. If the pressure is high enough (normal) then the guage will read in the normal area. If the oil pressure drops below specs, the guage will read zero. No in between. When you rev the engine, the oil pressure increases significantly from the pressure at idle. If you notivce, the guage on the dash does not indicate this change. All it sees is that the oil pressure is high enough to not cause problems, so it reads normal.

Drive any newer model Chevy or GMC truck. They have real oil pressure guages in them. The guages are marked with numbers in psi. When you rev the engine, you can watch the pressure guage in the dash go up and down. There is also a way to modify the guage in the Explorer to make it act like a real guage. There is a thread here on the topic, but with the search function down, I do not have the time to try to find it. Hope this helps.

 

[blk mk8]

i said it right the first time i think. if i was not clear its ok because every one understood what i said right.

 

[SteveVB]

sender

I would check your sender, and the wiring from sender for problems, also may be worth while to pull the sender and clean the passage out( a little oil will come out of the passage when you pull the sender ). Most likely its a bad sender.

7psi is the cut off I think for the gauge to move. I think the gauge will read middle until the pressure goes below 7psi or so. It is basically an idiot light like everyone pointed out.

The search function has some problems now, but there is a very long thread about the gauge and converting it to something that actually reads the pressure.

 

[Hank]

Search for an old post I did titled "Fake Oil Pressure Gauge" you will find everything you need in there. (Including complete conversion instructions and part numbers)

Best regards.
hg

 

[Tekeman]

Thanks for the great feedback. i'd sure like to do the conversion. i did'nt mention it but the check guage light comes on when it is idling and the idiot needle is bouncing. Don't know if this small tidbit makes a difference. for now i'm going to assume that all the mechanicals are ok. Under normal driving there appears to be no problems. What will i encounter if i do have a bad pump/sending unit etc.? High temp. distinct engine noise, smoke, smell,?? You guys that know your sh#t ROCK !!

 

[SteveVB]

check it to be sure!

If your worried about the pressure check it with a mechanical gauge ( a real gauge), any mechanic should be able to do this for you. Or you can get a decent mechanical gauge and hook it up yourself to check the pressures.- its really the only way to be sure.

If you wait for noises, heat to let you know- youve waited too long.

I left my FSM in the Garage, but from memory (its not the best ) the 4.0 oil pressure should be 40-60 psi HOT at 2000rpm. Im not sure what the pressure at idle is.

 

[Maniak]

Part Numbers

Since the search option isn't working.. Here's some part numbers for the oil sending unit.

The Generic one is OP24761
NeiHoff FF133E
SMP (no idea what that is) PS-60
The above part numbers are on the box that my NeiHoff part came in.


Once you replace the sending unit you still need to pull your gauge cluster out and short out the 220 ohm resister (you can't miss it.. it says 220 right next to it). If you don't short it your gauge will read low and slow.

Hope this helps..

~Mark