new 347 lost all oil pressure

dcurtis · Feb 22, 2012

First actual drive after installing the new 347, I drive about 5 or 6 miles and its running perfect, get about a mile from home and my oil pressure just instantly drops, was hoping it was just the gauge, but it isn't,t getting oil to the rockers, I pulled my distributer to see if maybe the shaft broke, its fine, its an arp and the pump is a new melling m-68, I guess the pump went bad, how hard would it be to pull the pump while still in the car?

txstang84 · Feb 22, 2012

Ouch...well, you can do it, but it sucks. The engine will still need to come up out of the mounts a few inches. I did it a looooong time ago with a floor jack and some wood chunks (2x4s and 4x4s)

Are you sure there isn't some kind of blockage? it would seem really odd to me that a new pump would be bad already-unless the over pressure plug popped. Do you have access to a priming shaft? Maybe the filter is clogged?

I take it the rockers/valvetrain got really noisy before you shut it down? Did you have a complete loss of pressure, or just temp/partial?

dcurtis · Feb 22, 2012

Yeah, it seems odd that a pump could do that too, everything is brand new so I'm pretty sure it isn't clogged, I was actually cruising in 2nd or 3rd and stomped for a split second, long enough for the tires to turn over and let out the second it broke loose and instantly the pressure was gone, drove about 3/4 of a mile home, no clattering of any kind, let it sit over night and fired it back up so I could look through the breather hole to see if i could see any oil and didn't, no noise at all though, don't really want too pull the entire engine as I just put it in Sunday night.

txstang84 · Feb 23, 2012

I'm going to make an assumption here and guess you're still using the factory gage... When you say you didn't see oil at the rockers-I take it you mean it was dry up top? was there no oil at all, or just very little? I'd still recommend using a priming shaft to find out if your pump just decided to go bad or if perhaps your sending unit came disco'd or maybe the wire is burned. There are other plugs inside the engine from the lifter galleys-I've had one of them pop out on me before (the one that is directly behind where the distributor sits in the b-dumps oil onto the dizzy if it's not installed). I'd get oil to the top of the engine, but not as much as I believe it needed...surely caused my lifters to die an early death too.

dcurtis · Feb 23, 2012

I'm gonna go ahead and pull a valve cover to see better and then try to see if it will prime with a drill and my old dizzy.

nine3cobra · Feb 23, 2012

this exact same issue happened to my engine when it was new and what it ended up being was one of the freeze plugs at the front of the engine next to the cam. it pushed out of the block under load and the oil system could not build any pressure. there were no oil leaks outside the motor since it was just venting back into the crankcase behind the timing cover.

txstang84 · Feb 23, 2012

nine3cobra said:
this exact same issue happened to my engine when it was new and what it ended up being was one of the freeze plugs at the front of the engine next to the cam. it pushed out of the block under load and the oil system could not build any pressure. there were no oil leaks outside the motor since it was just venting back into the crankcase behind the timing cover.

Those were the plugs I mentioned-they're not freeze plugs, but oil galley plugs to cap off the lifter galleys. I had one pop out as well...I still had pressure, but not enough.

dcurtis · Feb 23, 2012

That's some helpful info on the oil galley plugs, I would much rather pull my accessories than the pan, may do that since I would need to pull most of them to lift it any how, did you have any pressure at your gauge, mine doesn't even try to move.

dcurtis · Feb 23, 2012

I am using the stock gauge at this time, will buy a mechanical one Monday after I cash my check, what would cause the plug to pop out, just crankcase pressure, or oil pressure pushing it out, I did get on it the second before I lost pressure.

txstang84 · Feb 24, 2012

Well, I had pressure but it was somewhat diminished...I think the fact that I had an hv pump might have had something to do with that, but I don't know. But, I'd check that oil is pouring out of places it shouldn't be before pulling the front end of the engine.

The plug falling out could be just as simple as it wasn't pressed in straight, wasn't pushed in enough, or was over pressured. In my case, it was a little simpler-the <ahem> people who performed the machinework on my block installed press in plugs where it was threaded for pipe plugs (I had a Mexican block at the time, and they had threaded oil galleys). And I was a little too excited to put the engine together that I overlooked it.

Depending on how high you spun it, it may have popped out, but verify that you indeed do not have oil pressure and not just a bad gage, wiring, or sending unit before you start tearing into the engine...and using the priming rod (or old dizzy as you mentioned) will alleviate you from having to actually run the engine and potentially cause further damage.

Rick 91GT · Feb 24, 2012

That is one reason I switched and thread those oil passages on all the motors I do..... That sounds like the issue as long as the pump still spinds freely, amke sure you prime in a Counterclockwise motion.

dcurtis · Feb 24, 2012

Pump still spins free

Rick 91GT · Feb 24, 2012

If u pull the dist you can look with a flashlight and see if oil is coming out of the front of the block

txstang84 · Feb 25, 2012

...that's how I figured out mine was popped...but I used a priming rod instead of a dizzy, so I saw the oil gushing out like a damn geyser...

dcurtis · Feb 26, 2012

well, today I twisted my oil pressure sending unit and fired it up and it is now showing pressure, almost in the red at idle and rises with throttle.

Boydster · Feb 27, 2012

Sounds like a nice cheap fix then!

dcurtis · Feb 28, 2012

Well, bought a good mechanical gauge and pressure acts the same, barely any at all at idle and rises slightly with throttle, still no ticking. Have all ready pulled ac and power steering, and fan, gonna remove the balancer and then the timing cover here in just a minute, lot of work but I hope its just one of the galley plugs, hell, the shop that done my machine work forgot to install the cam plug at the rear of the block, so maybe they didn't install the galley plugs right either. Truthfully already aggravated with it, its all brand new with less than 20 miles on it.

dcurtis · Feb 28, 2012

Got the timing cover pulled, a pain with a one piece gasket, one of the oil galley plugs did pop out, havnt found it yet but still looking, should be running strong tomorrow, again.

dcurtis · Feb 29, 2012

Oh, when I pulled my timing cover off the front part of the basket stuck in the timing cover to pan rail, do you think it would work again with some sealant where it come apart.

Rick 91GT · Feb 29, 2012

It may, but I always buy the timing cover kit that comes with the new end rails. EVEN with the 1 pc gasket I snip it off with a pair of tin snips, and use ther replacement rail with "The Right Stuff" and let it set up over night.

Take a flat blade screw driver or a flat blade punch and stake the press in plugs in around the edges in three spots, this will help retain them.

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