i just fitted my oil pressure gauge and it seams to be making just over 1 bar at worm idle. The oil is 10-40 semi senthetic is 1 bar ok or is it to low

 

1 bar is very very low, some thing is not fitted or working right should be around 5-7 bar mine runs 70-100 psi. when driving

 

mines is a newage and sits at 3 bar on idle and 6bar when driving

 

My Type R runs at 2 bar idle when warm and 6 bar when driving,my Spec C runs 3.5 bar on warm idle and 6.5 bar when driving
1 bar is dangerously low

 

1 bar is on warm tickover and its about 7 bar when cold. When running it 5-7 bar. Is that really quite low then??

 

That's about the same as mine. 94 WRX with 10W 40 oil. Rebuilt 10,000 miles ago.

Cold start 6~7 Bar
Warm idle 1.5~2 Bar
Driving is usually between 4~6 Bar depending on speed/revs.

 

Ditto on my bugeye

Are you getting an oil pressure warning light come up?

My STRI gauges 'auto-calibrate' when I switch the ignition on' If I just start the car without letting the gauges go through their start-up 'dance', the readings can be innacurate, although this is normally only apparent on the boost gauge which needs to re-cal due to changing atmospheric pressures.

What is the pressure when driving normally? When was the oil/filter last changed? How's the oil level? Is it a reliable gauge? Can you bench test the gauge to see if it's reading correctly?

Unless you are getting 'knocking' from the engine or are suffering from high temperatures after giving it some welly i wouldn't worry about it yet. Could well be an iffy gauge/installation fault.

Good luck!

 

Just read your post again, 7 bar when cold is good, as is 5 - 7 bar when driving. I'd still bench test the gauge as the drop in pressure when warm idling seems a little extreme to me.

Is the car die for an oil change? Oil can/does reduce in viscosity over time and could give you this problem, especially if the oil pump is a little worn.

 

I had a new fiat uno turbo once, the expensive (£25 a gallon... in the 1980s...) fiat synthetic oil degraded in 1,000 miles giving low tick over oil pressure. I fitted shell gemini semi synthetic (now rebranded as shell helix) this did not appear to degrade, which fixed the oil pressure at tick over. Subaru UK recommend shell helix for imprezas (well classics at least maybe new age). You could try changing to shell helix if you are not already using it?

 

1 bar is fine at idle (if a little on the low side). More importantly you want to see 5 bar + when above ~3000rpm.


Jase.

 

I will take the car out for a blast in a bit to see what it is at 3000rpm. The gauge is a auto sport one of ebay it does look a bit crappy. How do you bench test the gauge then ?

 

just to add the oil and filter is new

 

On my old engine the pressure was just over 1 bar at idle and 5.5 bar running over 2.5 k revs after putting a td05 18 g on and bigger injectors it let go a week later due to the extra load on the crank bearings !! make sure it goes well above 4 bar from 2k revs if not suspect worn bottom end !! . Now running a EJ257 bottom end and have 3-3.5 bar idle and 7 bar driving (warm)

 

I just took it out and at 3000rpm it is at 3.7 bar. Im going to have to test the gauge. I dont understand why it should be low because i just rebuild the bottom end with new bearings and crank and plastigauged the bigends and they were ok . Everything elso looked ok and i used assembly oil on all the bearings??

 

I have just tested the pressure gauge and it is seams close enough. If the oil pressure is low would this explain the tapping im getting which sounds like tappets??
I think i might get a new oil pump as i did not replace it when i rebuilt the engine. Where is best to get a oil pump if i plan to do some track days would a 10mm be ok or should i get a 12mm one??