What's up everything? So brand new motor in the car talking about 300 miles it's a built long block running a 6466 and yesterday after I got done installing my new oil catch can setup went and did a pull, and everything was good the felt great! I am only running about 27psi on pump gas right now cause it's too cold for E85. But anyways the car felt good no smoking no knock just a solid pull. When, I got home I did have my GoPro on and going over the video I am looking at the oil pressure and I see its going from about 80 psi and when I am WOT it was around 59/65 psi and never went up after the pull it will go back up to around 70/80 and when coming to a stop and idle it will sit around 25/30 psi. Anyone have this issue? the gauge is a 150psi AEM and the sensor is in the stock location on the back of the block under the intake manifold on my 8.

If anyone has had this issue before, please what was the outcome.

 

Yes, this does happen. Are you running a new oil pump and what viscosity oil?

 

Its a stock oil pump not new and using 20w50 oil. I was thinking because its so cold outside that oil is still thick. I never had this issue before so want to see what others have done to fix this! I really don't feel comfortable hitting 8500 rpm with only 59/65 psi of oil pressure but thats just me.

 

The pressure is created due to a resistance of flow and this is affected by factors such as oil viscosity, bearing clearances and pump clearances, but ultimately regulated by the bypass spring pressure.
I had a pump failure when reusing a visually inspected pump on my 2.15L, which showed similar symptom of losing 10psi at WOT and reduced pressure at idle.

I am not saying this is your issue, but I would be suspect of the oil pump since it was reused. If you are noticing any reduction in pump pressures vs what you previously saw then that would suggest the pump. You can see my saga from my build thread at the link below, which details everything I did on this issue from start to finish.
https://www.evolutionm.net/forums/ev...l#post11913052

 

Where is your oil pressure sensor located?
On the OFH (Oil Filter Housing) or the back of the block?
Why are you running such a thick oil? What oil temps are you seeing?

When pump speed increases, the efficiency decreases.
And when engine RPM rises, the oil "consumed" by the engine increases due to bearings that have increases flows at higher RPM.

So either your pump is compromised, or there is something else in the oiling circuit that is "leaking" a bunch more than expected at the higher RPM.

 

My oil pressure sensor is on the back of the block in the stock location. I always run 20w50 VR1 in my built motors.
never had any issues. On, this motor I see the oil pressure will sit around 59 psi at WOT! Also, I am going to try and run a little bit thinner oil and see if I get the same results. If I do then I know the oil is thick and causing the lower oil pressure, but I just ordered a new oil pump and not going to chance losing a motor. The pump in the car right now it the OEM pump its been gone through and checked and cleaned and looks great that Is why put it back on, but I am just going to install a new pump and thinner oil and see what happens. I will be relocating the oil pressure sensor as well.

I know I will get a different reading on the back of the block VS the OFH so we will see what changes.

 

Depending on your clearances and with that oil it should be 90+ at wot. General rule is 10psi per 1000rpm .

Oil pressure aside I would strongly recommend a moroso, race fab or a modified oil pan/pickup if it’s got a good tire on it.

Overfilled a little isn’t a bad idea.

 

Oil clearances were set at .025, I just ordered a new oil pump, and I am going to go to a little bit less Viscosity and see if there is any change! cold start like 1st start of the day I'm sitting at 80+ once I get some temperature will sit at mid 70's and full warm at idle 25/30 psi. WOT high 50 low 60's.

 

Good call. I’d suggest measuring at the oil filter housing and stay with the 20-50.

 

I would say the change in oil viscosity is a problem to be fixed. I never run in any of my cars 20w50 below like 40 degrees. I swap it out for 15w40. I don't run my car in the winter anymore but I will still run it till it warms up. Changing the oil pump for a new one is a good idea for extra insurance. But the thinner oil in the winter should work with your bearing clearances just fine and keep it safe.

 

Yeah, I think the viscosity will help a little bit but for sure changing the oil pump and moving the sensor to the filter housing and see what happens! Again, I am not very comfortable revving out to 8500/9000 and only getting 59psi of oil pressure. Also, I really hope there is not metal shaving in the block!

 

Normally I would agree about staying with the 20-50 but if he is anywhere he sees cooler then 50 degree temps outside, that 20-50 is going to be like tar trying to go through that engine when it is cold out and trying to start on a cold start. Once it heats up it should be ok but still really thick oil regardless of what oil pump he uses. This is why I suggested using the 15-40. It is a bit thinner but it will hold up in the cooler weather and flow like regular oil will in colder temps, but thick enough for the protection the engine needs in cooler weather.

 

I've been running Mobile 1 5W-50 due to the cold start pressure being excessive with the 20W-50. I have it delivered by Amazon for a reasonable price.

 

If you can, I suggest doing one change at a time. Right now you have 3 items. Knowing which one actually made the change to your pressure is quality information!

 

There you go thats a good solution as well. Best part is its delivered lol.