Afternoon all,so after last weeks snowstorm it’s been high 70s all last week into the weekend,had to take the chero out for a cruise ran great till we were coming home,there was a noise that seemed to be coming from the passenger side engine compartment and the oil pressure dropped,pulled over,shut it off,looked everywhere around the engine,no oil leakage,dip stick read full,let it sit for a couple minutes,started it up and oil pressure was low,called for a flat bed to get it home,didn’t want to take any chances,after a 3hour wait the truck showed up,started it up to drive on to the flat bed and oil pressure was perfect,spoke to my mechanic and he thinks some crap was clogging the screen and once it sat the particles settled down into the pan,when I bought it I had my mechanic at the time pull the pan and he said the screen was clogged and he cleaned it,he said the pump was fine,if my new mechanic is going to pull the pan I want to replace the pump no matter what,problem is I can’t find one local,summit and macs say they have one,my biggest question is:is there more than one pump that was available for the 390?,was hoping to get some parts rechromed while it sat this winter but can’t spend any money till I know it’s mechanically sound,as my buddy always says:chrome don’t get ya home!also anything else that could cause the oil pressure drop?as always thanks in advance for any help or suggestions
It's been a long while since I put my hands on an FE, but with the pan off, you'll be able to inspect the pump, sump pickup and pump drive rod. Start, though, with a gauge test of the oil pressure, ensure the pressure rises as it warms up, look for any pressure drop-out at idle and at 1500 RPM. Remember, 20 psi minimum when hot is good, 10 or below at idle is bad.
Your first mechanic should have replaced the screen, there is always so much trash under the center strap that cannot be seen. I wouldn't worry about the pump itself, they just don't "go bad" out of clear blue nowhere, but make sure the new guy installs a NEW screen. That and I hope you're not using a Fram filter - I have seen 2 (with my own eyes) that closed up and restricted oil flow. Wix is good, so is Napa Gold (also made by Wix) Motorcraft, K&N, etc. If you do decide to change the pump don't sweat it, they're available, I should have one on the shelf, too.
Just order a Mellings pump from Summit, Jegs etc to be on the safe side. Like everyone said all ways use a new screen whenever you have the pan off. The Wix filter is in my opinion is the best one made. NASCAR race engine builders has used them since the 60's. Greg
