Oil Pressure Woes...'92 RRC

[usjess]

Hi all,

I've been working on resurrecting one of my '92 RRC's, sadly, it seems my oil pump has lost its prime and I can't get it to pick it back up. (Not so far, anyway).

A complication is that I'm in non-runner mode, at the moment, but when I had it running briefly (~2 minutes), it would not put out the indicator light, even when taken up to ~1500 rpm.

I changed the oil to a light viscosity full synthetic to see if that would help get things flowing again - no help, as a check of the new filter still shows it empty and full of air after quite a few engine cranks (with HT coil lead disconnected to prevent starting. This stuff is about like water at ambient temp, so I had high hopes.

I've removed the distributor and find that the oil pump drive tang turns smoothly and feels normal, turning by hand.

I'm out in the shop right now making a 'pre-oiler' tool so that I can use my drill motor to spin the oil pump drive tang and see if I can determine anything further.

Right now, it looks like my pump gears are worn beyond serviceability. I hate it, as I really don't have time to remove the engine and make that level of repairs, and time and finances (at the moment anyway) prevent getting one of the new short blocks.

She has 180,000 miles on the odometer, and I personally put over 100,000 of those on her, so its hard to remain detached in trying to decide what to do next. She has overall been a darned fine, realiable and economically efficient vehicle.

Jess

[Les Parker]

Have you tried priming the oil pump by filling the gears with vaseline/petroleum jelly? Also it helps by filling the oil filter with oil, prior to fitting it to the engine. Do you have the oil level sensor plugged in also?

[Terrys]

Packing the pump with vaseline is a good thing to do if you have it apart. Chances are better than not that your gears are really ok, it's the end plate wear that needs to be addressed also. Remove the pump end plate and (don't tell your wife I said to do this) start with a sheet of 400, on a granite counter top (or surface plate if you have access to one) and start lapping it in., then go to 800. Get all the swirl ridges out of the end plate.
The screwdriver bit in the drill works well to, making sure you're going in the right direction. When all else fails, pull the pressure switch out and put a fitting in there and pull a vacuum on it with you had vacuum pump, the one every mechanic should have for bleeding brakes.

[JeffL]

The advice given above is good especially lapping the end plates.
Another method I used once after loosing prime was to disconnect the oil cooler hose and apply a vacuum with a Mityvac hand pump. This filled the oil pump and filter with oil from the pan. I pulled the hose from the oil pump to cooler and with a suction cup looking adapter pulled the vacuum on the oil pump. Took about 5 minutes and problem solved.

[usjess]

Still trying for a fix...

Les - Terrys - Jeff,

Thanks for the helpful input. I'm still working the problem. I've tried but I couldn't get a vacuum with my Mity-Vac, through the port for the pressure sensor, (though there are no leaks evident) , so I tried back filling it from there, still no luck, so I pulled the gears out. There are very light marks on the endplate - I'll lap them out. The gears do look a bit worn, not sure how I'll proceed.

This problem started while sitting - not with an oil change, so that has me worried. i.e., it lost its prime for no good reason that I can see.

I'm worried that If I don't find a problem, it'll happen again.

Thanks again for all the help.

Jess