Oil Pressure Dropping


Hi There,

I've been driving my car a bit more lately after just finishing the interior refurb. I've noticed that the oil pressure is dropping at idle about 1/3 of the way in to the red. This is only after I've driven for about 30 minutes and it's well and truly warm. It never used to do this. I've changed the oil recently, but exactly the same type as last time. (I change ever 2000 klms) Engine feels as strong as ever. It's not blowing smoke or using any oil. After a few hundred klms the oil is still golden. With a few revs on oil pressure gauge climbs again to it's happy place quickly. When cold in the green all the time. Is this something to be worried about? Could it be the gauge/sender rather than the engine itself? Do other P6's exhibit this symptom?

Any help/advice would be very much appreciated.

Warm Regards,

Hi, The RV8 is quite tolerant of low oil pressure. Does the oil light come on? Have you checked the pressure with a separate capillary type pressure gauge? The dash gauge is not a precision instrument.

Hi Colin, I've not seen the oil pressure light come on, which is a relief. I have not checked with a separate gauge, not sure I have ever seen one. I will do some research. Neil not sure about the plunger, is this a part that is accessible for cleaning?
If you read the handbook it says in there that it's acceptable for the oil light to flicker on at idle when hot, providing you have some sort of reading on the gauge. That's not much help to the owners of a Series 1 though.....
Really? I wouldn't feel at ease...

I wouldn't feel at ease with it either, but nevertheless I've seen it written in there. Back in the day once an engine got to the stage that it was doing that it was time to whip the sump off and replace all the big end and main bearing shells.
Seems legit, lets hope it's not like that for Johnny though!

Mine drops to the lower part of green, when idling in D with a hot engine. If I put it in P it raises nicely, with the slight increase in engine revs. What kind of rpms are you idling at?
I have seen an MX5 pressure relief valve stick open - it produced ZERO pressure immediately, so I doubt that it is the problem in this case. Considering the oil flow inside the pump the scoring on the valve piston was quite a surprise. I have also heard that this is not uncommon in GM LS1-7 alloy engines, which have gerotor type crank driven pumps. You might want to see if moving up one step in oil viscosity helps.
Mine was doing all of the above. I slipped a "reel Steel" SD1 oil kit in.
No more flickering lights or OP gauge drop at idle when warm