I'm not sure if i have issues or not.... stock oil pressure gauge (i know...) reads 1 kg/cm2 at idle and 2.5 kg/cm2 at 3000 rpm. i'm running castrol gtx 15w40, and a fram oil filter.

i read somewhere on the forums that spilling oil on the sender unit might screw it up? i might've done this, not sure. otherwise, what could be the issue? how accurate is the stock gauge? this is an s5 n/a with 18xxx kms on the rebuild

thanks for the help

 

What rpm is the car idling at? I thought my oil pressure was messed up but really I had a vacuum leak and poorly adjusted throttlebody which made it idle low, hence low oil pressure.

 

the stock sender/gauge isn't the most accurate, but it will tell you that it has pressure and that the pressure rises when the RPM goes up. If you want an accurate reading I suggest using a test gauge or aftermarket gauge

*edit*
the stock sender is a 1 wire unit that uses the engine block as a ground. If the oil coats the outside of the sender, then it is possible that the gauge will read wrong ( a change in the resitance due to the oil shorting the connection)... just clean that area with simple green or brake cleaner and it should be fine

 

my oil pressure gauge is reading below thirty and right next to zero.

and i have no idea wtf is wrong with it.

 

one more note... you could put 5 different senders in and get 5 different readings

 

Was the engine rebuilt? If so, it could be the notorious front cover o-ring problem.
http://mazdatrix.com/faq/oring.htm

 

nah it wasnt rebuilt.
and but there is an oil leak out of a small tube that has no connects under my car.
but its nothing big.

and the oil is full and clean.
idk i think teh omp is going out.

or maybe its just cause its cold.

 

Im havign the same problem with my 3rd gen... my oil pressure is fine when you start it up.. but after 10-30 min of driving my pressure drops to zero...
Iv noticed oil drops underneath my engine.. mabye its a leak I dunno

 

- car idles at around 800 rpm
- is that front cover o-ring problem only for s4s it looks like?

i'll try cleaning the sensor itself tomorrow then and see what happens. but if oil is shorting out the connection then it should read higher than it is no?

thanks for the help guys

 

alright i banged my sunpro gauge in there while i was on lunch. at operating temp i'm seeing:

idle: 15-18 psi
3k rpm: 42-50 psi

so the 3k isn't near the 64-78 spec

 

I get between 50 and 60 at idle and over 70 while on throttle.

 

holy crap. any ideas as to what could be causing my issue?

 

sounds like a bad or stuck Eshaft thermo pellet for both chwkrx7 and Andrizzanizz

 

thanks icemark, where is that at?

 

behind the bolt on the e-shaft pulleys i believe

 

Kinda a side note but relevant, are fram filters not avoided like the plague or is that just a 1st gen thing?

 

Nope avoid like the plague... there was a thread just this last week here on that.

 

Hey, i just figured i should post up the solution here for future searchers. It did turn out to be the Thermo Pellet. I shimmed it, and now have no problems with oil pressure.

 

Very true.

Also for future reference...
The stock oil pressure sending unit is a diaphragm type (that's why it's the shape/size it is) and the diaphragm will relax over time which causes a low reading.
If you're going to rely on the stock gauge, the first thing to do is replace the sending unit with a NEW one and go from there.