Hi all,

Can I ask what sort of oil pressures people see from an Evo IX at warm idle? I’d also be interested to know how much that pressure drops with hot oil after a track stint etc.

With 10w50 oil I am seeing 15-16psi warm idle with road driving and 13psi at idle after a stint on track. When idling after track stints, I am
having the oil pressure light flicker/slowly fade in and out. I understand the light isn’t supposed to activate until 4.2psi so I have a new factory oil pressure sensor to fit on the next oil change.

The oil pressure with some RPM on seems perfect in all scenarios but I’m wondering whether idle oil pressure readings can be indicative of engine wear? If so, what sort of readings indicate a worn engine?

Many thanks

 

If the light is flickering then you likely have an oil pressure issue. I recently had a similar pressure issue although my light never kicked on and it ended up being a worn oil pump.

 

I did think that but the oil pressure gauge is motorsport grade (accuracy better than 2%@ 232 PSI) and the feed is from the oil filter housing like the standard pressure switch.

I do trust the aftermarket gauge more than the OEM switch, so I think changing the switch would be wise?

 

I see 25psi while warm, with 30w oil. I can't remember what it is when I come off track; I'd have to look... but I don't remember it being much lower, if any. Swapping the sensor is what I'd do first, then go from there. You are on the right track.

 

Swap the OEM switch and see if this eliminates the light flicker. Your pressures aren't too far off of what I see, which is ~18-20psi @150F oil temp and ~13-15psi @200F oil temp with Mobile 1 5w-50. Temp is measured in the sump on the pan.

 

First few track events in my Evo 8 I was using Rotella T6 5w40, and coming back into the paddock with 220-240* F oil temp I was seeing pressure between 8-12 psi, direct correlation temp vs pressure. Street pressure 15-20 psi with 160-180 temp.

Switched to M1 15w50. Better oil pressure after a track session- I think I netted ~5 psi across the board, temp vs. pressure.

However I did notice that the M1 15w50 would shear down a bit after 1 track day, and oil analysis confirmed this.

I switched to Redline. More shear resistant and stable with high temp abuse. Definitely a better performing, more robust oil. Again, improved pressure vs. temp.

 

No biggie since we do track days on fresh oil anyway. Not bad.

 

If the gauge is showing 13psi and the stock light is flickering, its just a bad switch.

 

Yeah, UOA confirmed viscosity was still bang on after one track day / five 20 minute sessions. I did two days / ten sessions once on the m1 15w50 and then sent it to the lab. It was smoked. Sheared down to less than half the viscosity value VS. 1 track day.

1 day: cSt viscosity @ 100 C* = 18.28
2 days: cSt viscosity @ 100 C* = 8.59

 

That is interesting. So literally need to change oil before each track day. I haven't done consecutive days before, so never really thought about that. Makes sense, though, and having proof lets you know you're not wasting your $$$