nipplebandit45

Well I just followed the advice from my previous post and tapped the rear banjo bolt on my water oil cooler for my oil presure gague. well the gague works, but it is reading around 60psi at idle and when I hit the gas it jumps to over 100. I'm assuming that this is not good.

What should my pressure be?

Mike

peejay

you tapped THAT one? hmm didn't think of that... usually you tap the one at the bottom (driver's side) of the rear housing, the oil cooler return line goes there except on '83-85 models, where there's just a thread-in blank plug.

did you try it with the engine warm or just dead cold? oil pressure will be higher when cold... on that note are you running 20W50 oil? someone told me that you should be very careful running 20W50 because it's too thick for the regulator(s) to bypass when the engine is cold... apparently you can blow a cooler hose off simply by revving a cold engine over 4k!

RB says you should have minimum 30psi or so at idle and 60 at 3k, dipping a little bit over 3k. (Mine runs 15psi hot idle and 30-40psi on the highway... uhoh) The factory regulator bypasses at 65psi, but if it overpowers it with cold oil, it's gonna spike up from that.

Meanwhile some people spend lots of money for oil presure like that

BadAssRX-7

ok you want to know why its SO high... you are getting oil from the pump to the cooler then to the sender(your gauge) then to the the pressure bipass then to the filter. you want it after the bipass not before. thats why the r.b. adapter plate is under the filter plate....after the bipass.

peejay

doesn't matter... it's going to be 60psi (or whatever) everywhere between the oil pump and the oil filter. the bypass is actually on a tangent to the main oil system flow.

nipplebandit45

well the bolt that I tapped and the ones that hold on all my oil lines are the same, so now my question is should I move i and if so where?

The engine was running cold, and yes I know that the pressure will be higher cold, but over 100??? that seems a bit high for just being cold.

ike

Siraniko

iTrader: (13)

if u have the fitting on the oil cooler inlet line banjo, then thats the right place. my engine is the same way and got the idea from the repair manual (hayes). there is a pic in the manual about connecting oil pressure gauge. at idle (engine cold), at least 80psi and goes over 100 if a drive it and drops to 70 once fully warm. just make sure to warm up the engine prior to driving it.


BTW anyone knows the max oil pressure??

peejay

there really isn't a MAX oil pressure, more like a MINIMUM oil pressure... as long as it doesn't drop down too low while warm, it's OK>

(ps I have a new avatar )

WackyRotary

I am somewhat concerned with oil pressure as well. If you know your first gen very well, like I do, you will find some interesting things about it eventually. Of course everyone knows about the oil pressure sender unit under the oil-filter. But some people neglate the reference signal unit on top of the engine that sits on a inspection plate that is near the back of the engine near the tranny. Its a little resister is the reference
signal the pressure sender unit to give its reading,
that is cylinderical in shape about a inch long thats hooked to the engine with a 12mm bolt. If this unit fails it will give you the wrong oil pressure. Usually it fails to the low side though. I found out the resister is about 1.83Ohms, I'm not sure of the wattage of the resister though. This is the reading you should get if you messure it. IT is set at the ohm amount so that at 3000rpm + you will get a reading about 60-70psi on your factory gauge as its supposed to be.

Stock electric gages are only there to tell you you have oil-pressure,....
not tell you what the actually pressure is. I promise you if you get a direct pressure gauge like the others mentioned, you'll find, that its probably just fine. ....unless you have really bad clearances between your engine bearings or your oil pump has a massive need of a overhaul kit, or your regualator is failing by by-passing too low.

gamble302

i hate to sound like a newbie, but how do i repair the sender? my oil pressure reads weird, jumps up and down a lot. previous owner said somethin about it but not how to fix it. any links to a fix?

also how can i set up a front mount oil cooler. ive got a nice big tranny cooler laying around here, would it be easy to set it up? the top mount thing on my 85 gsl doesnt work well at all.

peejay

HMM... My oil pressure reads low but the engine seems fine... while underhood checking for vacuum leaks I saw that unit on top of the engine... not plugged in to anything! No connector on the end, nothin, just a wire that ends. I dismissed it as a condenser and thought nothing more of it 'till now. What is it supposed to be connected to?

WackyRotary

Well, that resister I'm talking about is grounded to the engine, and also a wire comes out of it and connects to a connector about 4-5inches long. IF its not hooked up, you'll never get your correct reading for oil pressure. ...if I am talking about what you are looking at. I accidently wrecked my orginal one when I removed my engine the first time, I didn't see it was still connected and I busted the wire. I think a new runs you like $30!!! SHeee's. So go to a junkyard or radio shack and find a resister that is about .86ohms. or .83ohms. I gave the wrong value in the previous post.

peejay

Well the unit is still there, I just don't see what it was originally connected to.

WackyRotary

There should be a nipple like wire connection. A single wire the plugs into a female connector.