Ratchet23

ok so i finally got done swapping my 350 in for my 305, the motor is a 84 truck engine. well i pulled the oil pressure sending unit to scrape the block clean and me bein dumb i forgot to put it back when i drove the car home. (short drive like 20 min) well i got home ad realized what i did, bought a new sending unit and installed it started it and no pressure. figured it was the wiring or something so i disconnected it and the gauge moved so i pulled the valve cover. and there was oil up top the valve ad eveything, so i cranked over with the cover off and no oil came up. so now im dumbfounded on what could be wrong i had the oil pan off when i had the engine out and the oil pump looked fine, nothing was cloggin the screen and it seemed good or else i would have changed it. i just am looking for some ideas on what could be wrong

Thanks in advance

Chris

paulo57509

I think it's a bit late to look for what could be wrong. That already happened when you didn't replace the sending unit. You ran the engine with a huge oil leak (for 20 minutes ) and it eventually drained the crankcase of oil.

Anything you inspected before this incident happened is irrelevant.

I'm surprised the engine didn't seize.

Ratchet23

i drained the oil after i got home, there was at least 4 quarts of oil in the engine if not more.

Lurbie

iTrader: (3)

If you pulled the oil pressure sensor, drove it for 20 minutes and still had oil, then your pump wasn't pumping, or you didn't pull the oil pressure sensor, or the oil pressure sensor was in the wrong spot. It would've emptied the engine in a matter of minutes and you would've been puking smoke and oil behind you the whole way. Sounds like it's time to pull the engine back out.

Ratchet23

I know what an oil pressure sending unit is..... I definitely pulled it and had oil should I assume the oil pump is bad? I can get one today if that's what you would assume

Confuzed1

iTrader: (4)

I don't even understand this whole thing….

You say that you drove the car for 20 minutes with no oil pressure sending unit screwed into the hole.
-No mention if you were leaving an oil trail, whether you found oil all over the rear of the engine, no mention of the engine making funny noises or smoke rolling out from under the hood.

But you say you removed the oil filter, and there was at least 4 quarts of oil in the engine. So - the oil that drained out...was it nice and clean? Like new clean? Or was the oil was all sparkly with bearing pieces?

Here's what I'd do... make sure it has 4 quarts of oil in the oil pan, fill a new oil filter with oil and screw it on. Then start the engine with the valve cover off - then see if you're getting any oil at all up to the head. Since you've apparently ran the thing already without any oil pressure for 20 minutes….what additional damage could you do?….none.

Lurbie

iTrader: (3)

Didn't mean to sound like you didn't know, just saying those are the possibilities, sorry. I wouldn't say it's the oil pump. I'd pull the oil pan and drop the pump to see what's going on first. Could be a broken pump drive shaft, busted distributor gear, broken oil pump shaft, or a combination of those things. When I lost pressure on mine, it had busted one of the two fingers off the pump shaft, so the plastic broke off the drive shaft, and the part of the driveshaft that was supposed to fit between the fingers just starting spinning around the pump shaft, instead of spinning the pump. I wouldn't buy anything till you get it apart to see what's up. But honestly, if you drove this for 20 minutes with little or no oil pressure I really fear you've ruined your bearings. You may or may not have seen the silver flake in the oil when you drained it because if the pump wasn't working at all then the bearing material won't have made it to the pan yet. Then you may assume no metal is good, spend $100 or more on a pump and driveshaft or whatever's wrong and that new pump will wash all that bearing material down and you'll see it then. There's no easy way to check cam bearings, but when you drop the pan, you should drop a main or two and maybe a couple of connecting rod caps to check those bearings. Best of luck on this one, but I really think your engine may be toast. Hope I'm wrong.

Ratchet23

Last night when I was looking all over the place for an answer I saw something about the oil pump drive shaft and I pull my dizzy and the oil pun looked really far away so I just went out and bout the intermediate shaft, and the oil had a little sparkle in it but not too much honestly

Parrydise7

iTrader: (1)

Not sure I am following this, but it sounds like you are relying on the oil pressure gauge, which may be inaccurate. So, first, check to make sure that your gauge is accurate. If it is accurate, then check the pump and go from there.

I don't understand how you could still have four quarts of oil in that engine if the sending unit was not in place.

Lurbie

iTrader: (3)

So... are you saying the intermediate shaft isn't there? Was it there when you had the pan off before you put it the engine the car? If that things takes a couple trips around your crankshaft it won't end pretty.
Either way, you drove this for 20 min with no oil pump. Won't hurt anything but your wallet to buy another and see what happens, but I'd be planning a rebuild in your very near future.

Ratchet23

got it all back together and it has a slight piston wrap. i assume i hurt some bearing, will be doing a bearing in kit in the near future, well ill ever forget to check the oil pump again. they say you learn from your mistakes, im 17 im sure i have a lot more mistakes to make