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-   -   Oil pressure reading? (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/oil-pressure-reading-1020138/)

93vrfd_houston 12-10-12 08:37 AM

Oil pressure reading?
 
hello all, just got my rex back on the road after sitting up about two years while i was over seas. put in a new battery, did some slight modifications to the racing brake calipers so i didn't have to use wheel spacers, and an oil change.

for the oil change i used a 20w-50 royal purple synthetic, i know that a lot of people use different wieghts and say don't use synthetic. honestly it has been so long since i changed the oil in this thing, i couldn't remember what wieght i used last time. i know i used a royal purple synthetic but cant remember the wieght.

so i jumped on the forum and checked FAQ's and it seemed that the most common viscosity was the 20-50. the issue is i drove about 4hrs from chorpis christi tx to houston tx last night. oil pressure is too high for my liking.

if i am running over 65mph, i am seeing oil pressure just under 120lbs. this is higher than i would like to see and want to know what you guys are running. oil level is slightly under the full mark. am i just paraniod or am i correct in assuming that this type of pressure could cause some kind of seal malfunction?

thanks for any help,

CloudPump 12-10-12 12:58 PM

That's a lot of pressure.

50psi at 3k rpms is factory spec (at operating temperature)

-Geoff

tek_88 12-10-12 01:14 PM

Yeah that seems like way to much oil pressure. I get ~20-35psi at idle and 60psi while cruising on the freeway.

Tem120 12-10-12 02:15 PM

that definitely seems like way to much , what is it at idle ? what is it at operating temps , vs when you just start the car?

Richard.C 12-10-12 02:59 PM

I thought the fd3s had 110-115 psi oil pressure, mine gets 100psi by 2800rpm.

Articles like the following are what have led me to believe 110psi is normal.

RE:FC3S 13BT vs FD3S 13B-REW


Richard

CloudPump 12-10-12 03:16 PM


Originally Posted by Richard.C (Post 11312768)
I thought the fd3s had 110-115 psi oil pressure, mine gets 100psi by 2800rpm.

Articles like the following are what have led me to believe 110psi is normal.

RE:FC3S 13BT vs FD3S 13B-REW


Richard

FSM says 50psi at 3k rpm

-Geoff

93vrfd_houston 12-10-12 03:43 PM

thanks for the input guys, been out of the scene for a while. at start up and normal operating temp, pressure is reading at idle 50-60~. after driving at normal conditions, no getting into it and just cruising at hwy speeds 70-80mph....pressure was about 115-120~

we got a cold front this morning and outside temps were in the mid 40's......pressure showed 60 at start up and idle and 115-120 at cruising speed about 50-65mph when cold and at operating temp. don't know exact temp as i am just using oem temp gauge as well, but below half mark.

i am using the stock oil pressure gauge, i know that the sending units are tricky and can cause some issue's. but from what i can find on here they normally read low and i don't want to take a chance doing any damage to the motor.

Sgtblue 12-10-12 05:24 PM

Seems normal to me for fresh oil in that viscosity and with that ambient. 10w-30 would be more appropriate and will lower the reading.

And IIRC the FSM doesnt specify an oil pressure. It states MINIMUM is 55 psi at 3000 rpm.

Mahjik 12-10-12 06:30 PM

1 Attachment(s)

Originally Posted by Sgtblue (Post 11312919)
Seems normal to me for fresh oil in that viscosity and with that ambient. 10w-30 would be more appropriate and will lower the reading.

And IIRC the FSM doesnt specify an oil pressure. It states MINIMUM is 55 psi at 3000 rpm.

Yes, this is correct:

Tem120 12-11-12 07:41 AM


Originally Posted by Sgtblue (Post 11312919)
Seems normal to me for fresh oil in that viscosity and with that ambient. 10w-30 would be more appropriate and will lower the reading.

And IIRC the FSM doesnt specify an oil pressure. It states MINIMUM is 55 psi at 3000 rpm.

Dont mean to hijack the thread or anything , but is there any negative effects to having the pressure so high? more blowback?

RENESISFD 12-11-12 07:51 AM

Pressure is resistance to flow.


The more pressure the lower flow (generally).

If the pressure is too high you will be bypassing most of the oil through the pressure relief valve so the engine will not get the lubrication it needs.

adror8 01-23-13 09:31 AM

I have a digital pressure gauge (Innovate) which max out at 100 but sender unit withstands 150PSI. Engine starts at 100 (max) and slowly drops to around 40-50 as it warms up. It cruises at around 90PSI at 3K. If that helps any one. I use 10/30 synthetic. The gauge is dead on accurate and it is installed after the oil cooler. It just dosn't read past 100. Was told by Innovate that going over does not affect the accuracy nor the reliability of the sender as long as pressure is <150PSI. Does anyone have an after market gauge installed that reads past 150PSI? What are you seeing for readings (especially max). I'm curious as to what the pressure peaks at. From what I read around it specs to 120PSI max.


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