Oil Pump Issue

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OK, both gauges installed, no leaks, both work. My Oil pressure at idle was between 35 - 40 on my '75 Slant 6. I didn't drive it cause I ran out of time.

For the Oil Pressure gauge, I removed the factory oil pressure sending unit and ran the end of the mechanical oil pressure gauge there.

For the Temp gauge, I used the Coolant Control Idle Enrichment Valve (CCIE) port on the head near the stat so my dash gauge still works too.

I routed these the best I could with the amount of line supplied with these gauges, each should have been about 6" to 1' longer.
 
If that pressure was at a fully hot idle, that's good oil pressure. If that's right when you started it, not so good. Make a good long pass down the highway before we pass judgement on the sender (and bearings).
 
Ok, here's the data. First let me add some info I found in my 1975 factory service manual. According to the manual Minimum oil pressure for the slant six at idle is 8 lbs of pressure. Operating pressure should be between 30-70 lbs @ 2,000 rpm.

I went out for a nice long cruise tonight. At between 180 and 190 degrees driving at 60 -70 mph my oil pressure was around 35 lbs and as high as 38/40.

At idle at a stop light it was 10 lbs on the nose.

What do you guys think? FSM says it's kosher, but....... 10 lbs at idle and 180 degrees?
 
roadrunnerh said:
Ok, here's the data. First let me add some info I found in my 1975 factory service manual. According to the manual Minimum oil pressure for the slant six at idle is 8 lbs of pressure. Operating pressure should be between 30-70 lbs @ 2,000 rpm.

I went out for a nice long cruise tonight. At between 180 and 190 degrees driving at 60 -70 mph my oil pressure was around 35 lbs and as high as 38/40.

At idle at a stop light it was 10 lbs on the nose.

What do you guys think? FSM says it's kosher, but....... 10 lbs at idle and 180 degrees?
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why are you associating running temp with oil pressure?

you should be associating rpms with oil pressure. 10 psi for every 1000 rpms is great and plenty. its coming up with the rpms so you are good. 180* running temp is great as well. stop worrying bro, your engine is doing what it is supposed to do, GO DRIVE THE THING !!!!
 
Just saying the temp because of the oil light flickering when I was at idle and I was concerned about pressure. That's why I installed the gauges. No tachometer...yet.

Thanks 73AbodEE, I don't want to get all OCD about oil pressure! :rolleyes:
 
roadrunnerh said:
Just saying the temp because of the oil light flickering when I was at idle and I was concerned about pressure. That's why I installed the gauges. No tachometer...yet.

Thanks 73AbodEE, I don't want to get all OCD about oil pressure! :rolleyes:
Click to expand...

i can totally understand the worry, but you are good to go. just watch your gauges and enjoy. worry when you have 3 pounds of oil pressure and your temp gauge reads 240* lol
 
I don't know if I would be worried about those oil pressure readings but I wouldn't be overjoyed with them either. They're a bit low in my opinion. The slant 6 daily driver I drove for almost 25 years had better oil pressure than that when it had over 250K miles on it. Mine would max out at 65 psi when cold (yes, temperature will effect pressure readings) and still hit 50 psi at full operatiing temperature and at freeway cruise speeds. It always idled at 20 psi....and this was a manual trans vehicle so the idle was a bit lower than an automatic.
 
Your oil pressure is certainly on the low end of acceptable, but still acceptable... Go ahead and drive the car but pay attention to the oil pressure when idling hot. Next oil change put in some thicker oil like 15W-50 along with a high quality filter, I don't think 10W-40 will make much of a difference from 10W-30 but that's just my $.02...

Also a +1 on getting a tachometer, really no reason not to.
 
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