Odd il change/pressure/temp issue

[mxsx25]

Engine specs
Cp 9.0-1 pistons
Eagle h-beams
Bored .020
Tomei metal hg
Arp hardware
Nissan specific bearings
Refreshed head
Etc.

For first 500 or so miles I ran 5-30 non synthetic because I've always had
Doubts abt synthetic oils... Built engine myself meticulously, and now at about 1300 miles I decided to go synthetic

I have aem oil pres and oil temp gauges located on the greddy relocate

This is where im confused

Average specs before oil change
Pressure at idle- 19 to 24
Temp- rarely above 110

DIRECTLY after oil change
Pressure at idle -16 to 19
Temp- 160 to 175 driving normal


Also replaced filter which seemed like a 300zx filter with a fram filter (from a 91-94 ser as I was told...


Can someone explain this to me? I'm nervous, but at the same time am wondering why my old oil wasn't heating up... Any info is much appreciated guys

Zilvia knowledge ftmfw!

[KaminaSan]

Engine specs
Cp 9.0-1 pistons
Eagle h-beams
Bored .020
Tomei metal hg
Arp hardware
Nissan specific bearings
Refreshed head
Etc.

For first 500 or so miles I ran 5-30 non synthetic because I've always had
Doubts abt synthetic oils... Built engine myself meticulously, and now at about 1300 miles I decided to go synthetic

I have aem oil pres and oil temp gauges located on the greddy relocate

This is where im confused

Average specs before oil change
Pressure at idle- 19 to 24
Temp- rarely above 110

DIRECTLY after oil change
Pressure at idle -16 to 19
Temp- 160 to 175 driving normal


Also replaced filter which seemed like a 300zx filter with a fram filter (from a 91-94 ser as I was told...


Can someone explain this to me? I'm nervous, but at the same time am wondering why my old oil wasn't heating up... Any info is much appreciated guys

Zilvia knowledge ftmfw!

Time for an oil cooler...

Honestly, I wouldn't worry about idle pressure too much.

I'm also in the same boat as you. Just fully built my SR, and after driving it normally, the oil pressure is about 20 psi, idle, and 70 psi at 3600 rpm.

Strange thing is I have my oil squirters plugged for Mahle Pistons, and I'm running 10w-40, so I should be at a much higher psi, especially with a new pump.

It's all about the heat, and the oil thickness. I would personally never run 5-30 in a turbo engine unless it's 20 degrees where you live. 10-30 at the least.

[mxsx25]

Well I did a ton of research and can't seem to find definitive answers about what viscosity of oil to run, but my point is I went from a less expensive non synthetic which hardly ever broke 100 degrees F* to a high quality full synthetic ( both were 5w30 tho) so how come the sudden spike in heat literally directly when I changed oil? Also note I live in nh and it's winter now so should I still switch to 10w30/40?

[Jared0934]

I would recommend 5W40 if your in new hampshire this time of year. 5W will let it start easier in the cold. I'm guessing you run a SR? so the 40 rating is nice because SR's innately get hot so the 40 rating will keep things running smooth even at high rpm. Since the engine is modded as well it's always a smart idea to buy an oil cooler, even one off ebay just do your research and pick the rite seller.