oil presure

[goatijoe]

i have been seeing that my oil presure has been geting higher and higher for some unknown reason since i got my truck. it started off at about 40 psi on idle and about 75-90 psi running down the road. but now i have 60psi at idle and 90 psi ++++ ive seen it peg the gauge out somewhere past 120. has any of yall ever seen or had this problem. the motor does not make any strange noise. is there any where that i can hook a oil pressure tester up besides where the oil sending unit is way down on the right side at the back. any advice would be much appreached.

 

[goatijoe]

I guess no one has seen this before.

 

[swbradley1]

If it were me I would pull the sending unit and test it there.

 

[goatijoe]

i saw where the sending unit was I didn't know if there was another oil passage that was easier to get too

 

[Nonotagain]

i saw where the sending unit was I didn't know if there was another oil passage that was easier to get too

Just purchase a 1/8" npt T and some fittings and have both come off the same port.
Increases in oil pressure typically are seen when the resistance in a oil filter increases.
How long has it been since the oil was changed?

 

[Karl kostman]

You are going to have to pull the sending unit and have it tested, its a little tough to get at BUT its the first place to start, 90% chance that is your problem.
KK

 

[goatijoe]

the oil has been in there at the most 2000 miles. i put rotella 15-40 back in there. do you think the oil has cleaned the gunk out in the filters do to the cleaning addatives they put in the oil. who knows what kind of brand of oil they used in it. or do i need to swap to a hd 30w oil with no detergents in it next time i change the oil. where would be the best place to see about geting a sending unit tested or is there a omm reading that they are spose to have that i can test my self. im just trying to get ideas from yall that have worked on these before im use to the hd truck motors. i know some of those better than the back of my hand .

 

[bguy193]

The oil preassure gauge works just like a civy one does. If it is pegging out it is probably the sending unit. As oil preassure builds the resistance inside the sending unit decreases, sometimes when sending units start to fail the resistance inside the unit weakens causing a higher preassure reading. If you dissconnect the wire from the sending unit and ground it to the engine the gauge will max out due to no resistance. I would start with the sending unit......if you remove the air filter drum, it should be easier to get to.
Good Luck and happy trucking

 

[G-Force]

Take the wire off the sending unit and see if the guage goes full scale. If it does then you have a wiring issue or a bad sender. Or it also could be a bad ground which is what I'm betting on.

 

[greg2560]

my temp guage was reading hot. the guage had a bad ground in the mount in the dash

 

[JasonS]

Increases in oil pressure typically are seen when the resistance in a oil filter increases.
How long has it been since the oil was changed?

But isn't the sending unit downstream of the oil filter?

 

[goatijoe]

I unpluged the wire at the sender and plugged it back up to see if it had a good seat. I think it was all the way in but I plugged it back up fired it up and it was reading right some how. I'm guessing that it just had a bad connection in there somehow. So I'm taking a wild guess that its fixed.

 

[Nonotagain]

But isn't the sending unit downstream of the oil filter?

I used to see the same effect on my road tractor.

I drove as a team driver and the truck was driven almost 5,000 miles a week which also happened to be the oil change interval. After 2,000 miles or so the oil pressure started to increase by 5-10 psi.

 

[goatijoe]

wonder why the oil gained pressure in it. id thought it would have droped from being a bit thiner