My '73 ES registers oil pressure at about 30 lbs. while at speed. Lower at idle when warm. Light never comes on, but registers low on the gauge. Either 92k miles or 192k miles, no way to know for sure.

What's normal?

Are you sure of your gauge?
It would not be unusual to see it as high as 65 but 30 is probably adequate under nonabusive driving.
The oil pressure is normally controlled by the pressure relief valve on the oil pump.
Sometimes they get a speck under the ball and it never quite closes, which would cause readings like you see.
If you are getting plenty of lube in the rocker chamber you are probably in good shape.
--
George Downs, Bartlesville, Heart of the USA!

George, can the oil pan be removed without pulling the engine? Disconnect motor mounts for extra room = enough?

1800ES

Ron

I've never had an 1800 of any description so I don't know for sure but you would almost have to drop
the crossmember, which is about as much work. I did that once on a 122 wagon. Fortunately I was able to get enough torque on the bolts that had held the member to the frame for 35 years.....
Other than that it wasn't TOO bad.
Lotta things to remember in either case, like the ground strap.
--
George Downs, Bartlesville, Heart of the USA!

On an 1800 it's just like on a 122 except that the crossmember bolts are located a bit differently. To my mind, it's only a little bit more work to pull the engine rather than drop the crossmember, and then you have much more comfortable access to the pump and whatever else may need looking into.

I dunno, I may tend to disagree. If all I'm wanting to do is pull the pan and tinker with the lower end a bit, I might just elect to drop the crossmember. And "drop" is a bit of a misnomer, because it doesn't have to be completely separated from the car, rather lowered a few inches IIRC. I've done this on both a 544 and an 1800, but it's been a few years. Okay, maybe several years. Well, I suppose 35 or 40. :-)

In any case, part of the decision process has to be what you're equipped to do. At least that was what helped make up my mind at the time.
--

Gary L - 1971 142E ITB racer, 73 1800ES, 02 S60 T5
BlueBrick Racing Website
YouTube Racing Videos

What I've done on 140's is to jack the motor (remove radiator mount bolts) a few inches--enough for the mount pins to clear the subframe bracket and block up with a piece of wood on each side under the mounts. Underneath I loosen the front subframe bolts a few turns and then with the subframe supported (pole or floor jack) remove the rear bolts and then lower the subframe--I use longer than original bolts reinserted a few turns just for safety. That gives you just enough room to get the pan off.

The gauge is the original. Valve rockers all wet.

Any way to clean the oil pressure relief valve? I think the answer is only by removing the pan, right?

Where else to check oil pressure? Would the original gauge somehow lose it's accuracy over time?

Other ideas, besides just not worrying about it?

Ron

It's possible the original gauge is not accurate - you could substitute another gauge hooked up to the same
line (unless it is electric, then you'd have to hook it up in place of the sender.
Yes, you have to pull the pan to get to the oil pump. Once you do, it's right there.
Should replace oil line seal rings when you are in there. Also clean oil pump and relief valve.
--
George Downs, Bartlesville, Heart of the USA!

Thanks, George. Will check it out.

I had a '68 late (B-18) with lousy oil pressure, even though I couldn't find any
(exterior) reason for it. Once I was committed to removing the oil pan, I found that the rubber(?= square sided "O" ring) seal which was on the pick up tube into the block was defective. It had been installed sloppily, had shifted, and basically didn't make a good pressure seal. Replaced the dime sized seal with a new one, reassembled everything and voila; 60+ oil pressure!
Moral of story; sometimes the biggest sounding problems have pretty simple answers. Bite the bullet, get in there! Good luck.

Thanks for that extra tip.

Question: Can the oil pan be removed with the engine in the car, and the front suspension intact? Put another way, what's involved with removing the oil pan?

Several years ago I replaced the oil pan gasket on my 1800ES without much drama. I think I might have had to loosen the motor mounts and slightly elevate the engine with a cherry picker, but I don't recall removing the cross member.

My car shows around 30 psi at idle when the oil is completely warmed up and ranges from 50-65 psi when warm and running at normal operating speeds.