I swapped in a swap meet 350 long block and crossed fingers that it would run, at least well enough while I saved up for a rebuild. I used the TA water/oil pump assy that was on my 340 (that came in the car) and was working fine there. Got it running, appeared to run well, drove it to the exhaust shop and back, about 12 mi, at 20mph. On the way back the oil light came on. Coasted back to the house, put a mechanical gauge on, no pressure. Dropped the pan, all looked fine, the pickup seems in good shape and well secured. Took the oil filter off, I don't think any oil had gone through it ever . Took the oil pump apart- the pressure valve plunger seemed a little stuck, but not bad. Cleaned it, started it, still no pressure. How did I ever make it to the muffler shop and back?? I realize my mistake has probably done serious damage to the engine. What should I do now? Why no oil? I'm about at my wits end with this project. Any help would be appreciated.
Is your distributor nestled down all the way to drive the oil pump? Or you may have a leaking oil pickup connection & sucking air and not oil.
Did you prime pump? With oil or grease? You mist have hadsome oil pressure to get that far. But I would think you want to pull and inspect bearings. Lost prime or sucked air if it did have prime. Keep looking for the problem. Pulling engine back out for inspection might be needed
It's a good idea to prime the pump by filling the pump cavity with Vaseline. If you have a spare distributor lying around you can knock the shaft out of it, grind the teeth off the gear and use it to pre-pressurize the engine before you start it. If you only drove 20 MPH you may not have hurt it, but, it would be a good idea to look at a few rod bearings.
Did you prime the pump before start up? No pressure gauge Im assuming, just a light? If you HAD pressure and lost it on the drive to the muffler shop, you would have heard the lifters chattering first, then the death knock from the bearings. If you had NO pressure on start up the lifters would have made it known, and your light SHOULD have been on. Pack the pump with Vaseline, prime, then restart and verify pressure.
Yes, that far the bearings would be damaged. He’s getting oil just not pressure. Either the relief valve is stuck, has something stuck inside it, or a oil galley plug has popped out.
I had this very same issue awhile back, oil change, take AC filter off, the center (return to engine) part of the filter was dry, then after a few seconds, oil would run to the center section of the filter. This happened about 4 or 5 times with the AC PF24 filter, NEVER found out why the oil was not passing thru the filter, BUT I did have oil pressure. I don't know if AC's quality control went down hill or what, I just had this happen again, Im seriously considering a washable filter like Larry has or similar.
Pull the distributor and run the pump with a drill for a minute and see if oil is flowing to the rockers. That might give you an idea of where to look. My oil pressure light is pretty sensitive, so I'm surprised it didn't come on immediately at start and stay on if your oil wasn't circulating. Since it didn't roast/lock up/squeal like a pig, I would figure out the oil problem, fix it, then drive it to see if you have any issues related to no oil (pings, knocks, tappets, etc.) before I pulled it apart and replaced bearings and such, especially if you are building another motor.
Id look at #7 and #8 rods. Those are the the bearings to go of oiling is a concern. If theyre good, rest of the motor should be ok. I think its a priming issue. Pack with normal NON baby powder infused or scented VASELINE (the type in the jar, thick stuff), and hook a gauge up. Should prime first try. Or spin with a drill as said. Put oil in filter before priming either way.
Finally had time to make some progress on this. The oil pump wasn't priming. I dropped the pan, pulled off the pickup, stuck a clear tube into the pickup hole in the block and into a container of oil, and watched while someone turned the oil pump. Even with the oil filter filled and oil being pumped into the sender hole, the pump was only pulling the oil up ~1" from the container. I packed the pump full of vaseline and then oil shot right up the tube. After that I was getting 35lbs of pressure. I ran it for a while while it warmed up, seemed to be running good (but again no exhaust so hard to hear noises). The pressure slowly dropped as it ran, back down to zero after about 5 min I changed the oil/filter thinking maybe debris from running it earlier could be entirely plugging the filter (and put in 20w-50), but no pressure again at startup. Spun off the new filter- dry as a bone inside! Looks like my pump lost prime again? What could be causing this? How does the pump lose prime while it's running?
Yeah, this is a head-scratcher. Haven't heard of a pump loosing prime after it has gotten going. Just some thoughts... Have your opened up the pump to see it it is really bad scored inside? What oil filter are you using? Is it a stock oil pan and the pickup is fully immersed in the oil? Could be a chunk of silicone or carbon in the oil passage between the pick up and the pump that gets lodged after the engine runs a little. Distributor has its retainer and is tightened down? Pressure relief valve limits pressure to 40 lbs, but I don't know if it being bad can reduce pressure. Oil filter by-pass valve could be stuck, that would keep oil out of the filter. Is the sending unit good?
I had this happen on a V6. I was doing an oil change. put the new filter on and filled with oil. Then would not prime. The timing gear teeth plugged the pickup screen. You could run the engine with no oil filter on it and not 1 drop of oil.
