Oil Pressure

[bigbad79]

does anyone know any tips to get a correct reading on oil pressure? i just replaced my oil pump and changed the oil of course. when the truck first starts the oild pressure reads about 25 to 30 psi. then as the truck warms up the pressure drops till the gauge reads 0. i dont think its the gauge since its a brand new autometer. what else is there to replace? the motor sounds fine even when the gauge is reading zero, no knocking or anything unusual also

 

[4xfan78]

what weight oil do you use? Is the gauge electric or mechanical?

 

[bigbad79]

its a mechanical gauge. the oil was quaker sate 4x4 sinthetic blend. this was the first time i changed the oil since i bought the truck. i cant remember the weight

 

[4xfan78]

Since the oil is new and the gauge is new the only thing that I can think of is there might be a leak in the oil line from the engine to the gauge.

 

[bigbad79]

i replaced the oil line but is there supposed to be oil in the actual line going to the gauge or is it just a vacume line?

 

[STLKIKN]

A mechanical gauge should have oil in the line.

 

[bigbad79]

yeah i replaced all the fittings and hose to the gauge and the pressure when i first fire the truck reads at about 50 psi which is pretty normal i guess but it seems that as the truck warms up the pressure still drops till it reads zero. with the new hoses and fittings it took a little more time than before but still the same result. what else is there to look at?

 

[BigNasty]

Ya did put oil back in the motor at the last oil change..right?

(ignore the smart arse... me )

I would try a real oil and see how it reads.
I have had issues with synthetics in the past, especially in V8s.

 

[bigbad79]

yeah def oil in the truck. i'm out of ideas so i'll give some regular ole' oil a shot an see what happens. prolly gonna take a few days to do since all the damn hurricanes in florida keep me insude instead of in the garage turnin wrenches :angry:

 

[BigNasty]

Hurricanes?

Yeah, no kidding!
The rain from the first one that came thru flooded my engine and I didn't know it till I went to crank it.... and now another ones in Florida...
Florida is nothing but a storm magnet this year... I feel we should sink it and move on

 

[Broncoholics]

You should bleed out the air in the oil line. Take the tube off the back of the gauge and tick the engine over a few times until oil sprays out the tube. The reconnect it and test it after you top off with 20/50 oil. Air doesn't compress the same as oil but should keep you close to accurate even with air in the line. Seems odd to have 0 psi after seeing 50 psi. Try some Hyper Lube woth 20/50 or perhaps the oil pump is shot.

 

[bigbad79]

i'll try bleeding it. the oil pump is brand new tho, thats why i'm so lost with this whole thing. i'm also gonna ditch the synthetic oil i put in it when i changed the pump. what do you recomend?

 

[bigbad79]

so after bleeding the line to the gauge, changing the oil for some 20/50 and changing the oil pump i still have the same problem. i'm gonna try using the old pep boys gauge that was in it and see what happens, maybe the autometer is a defect? i'm just about out of options :angry: