No oil pressure on motor that hasn't run in several years

Just bought a 92 jeep that has sat since 08. Started it up, ran fine but in a min or so the valve train started to get noisy. Checked the oil pressure gauge and it was zero. I neglected to check if it was getting pressure when it first started.

And ideas? Will a 4.0L lose its prime if it's sat for awhile?

I know the jeep ran fine when it was shut off.

How long did you let it run? Might need to pour or spray some oil in the cylinders to help relube and get the seals back up to par. Or maybe the oil pick up has sludge in it not allowing oil to come up?

My money is on the sludge. The pickup screen is
very close to the pan bottom, and I'll bet the
oil contaminates have settled out to the bottom
and clogged the oil pickup screen.

The solution would be to pull the pan and replace
or clean the pickup screen.

From Orange Can of Death, perhaps?

I don't think so but I can't remember. I don't remember seeing any Orange on it.

Does it have any oil in it?

Yeah. It was right on the full mark. Oil is very clean. The PO (TomR here) is very meticulous. It's not been abused and knowing him it probably had the oil changed 200 mi before it was due.

DrMoab said:

Just bought a 92 jeep that has sat since 08... Will a 4.0L lose its prime if it's sat for awhile?

I know the jeep ran fine when it was shut off.

Click to expand...

Y-E-S!

As I sit under my shade tree, nursing my sunburned neck: You should have known to prime the oiling system, regardless of brand or displacement.

Easy method: Ground the coil wire and crank the engine until you see pressure on the gauge.

More elaborate method: Pull all the plugs, ground the coil wire, and crank the engine until you see oil pressure.

Most elaborate method: Leave the plugs and wires alone, pull the distributor, and put a 1/2 HP drill on the oil pump drive to prime the oiling system.

If it has sat for a year, I'll start with the easy method. Anything longer than a year, I'll jump to the most elaborate method. I added the second step for the uninitiated and the lazy Mo-Fos.

Disconnect the CPS. crank til you see pressure reading on gauge. Plug CPS back in. Be sure you have a good quality oil filter on the engine. Nothing orange. .

Pulled the distributor and manually primed the pump. Bingo. Oil pressure for days.

You can't knock that!