Petrol engine oil pressure

[Scoota]

Can anyone give me an idea of what oil pressure petrol engines would usually run at? I put in a fairly crappy 'autogauge' electronic oil pressure gauge the other day, it was new - but i understand they are very cheap, so not sure if thats giving me false readings or if my relief valve is sticking?
Started from cold it will idle at 90psi - off the gauge while driving(100psi+), once warmed up - idles at 50-60psi, open road driving in 5th@100kph = 90psi. driving hard = 100psi+
Vehicle is a 94' mitsi pajero 3.5lt v6 SWB with 200k on it.
Is this normal? or do i need to investigate further??
Cheers - Travis

[MikeL200]

Dunno about the gauge, I have them in my V6 3litre L200 and don't have problems with them (oil pressure and water temp). I get about 60 psi on cold start-up, then drop down to 20-30 psi once warm.

Mitsi engines generally run at 10 psi per 1000 rpm.
Check what grade oil you have and maybe a flush and filter change would help.

[muddyhilux]

hi mate,don't know the motor but know the gauges,they're cheap but ive only ever had one faulty gauge and 1 faulty sender,and ive put them in a number of vehicles,biggest thing ive found with them is the earth's got to be good and they can pick up interference easy,thats what it sounds like to me and ive had similar,off gauge when cold and good readings when warm,go and check your eartha nd maybe run right to motor to be safe.only thing i can say about actual readings is i know my brother n laws d21 2.7na diesel runs 75psi idle and 100 psi going hard

hope that helped

edit

man i need to read better,its a petrol ,in that case ignore the last comment haha

[Scoota]

Thanks for the replys, yeah i will redo the wiring, its a bit bodgy at the moment - I lost the wiring diagram, and there is no identification marks on any of the terminals on the gauge! the sender is marked with "W.L" which i figured was to the gauge, and "G" which i assumed was to ground. I gues its possible i have got something around the wrong way some where..will have another play with it tonight. If anyone has a wiring diagram for an autogauge oil pressure gauge with a two pin sender that would be a huge help.
Cheers,
Travis

[muddyhilux]

oh yeh theres the prob mate.g is for gauge and wl (although mine is wk) is to ground