thesiren74
Well-Known Member
Sounds like a pump issue.
Oil pressure drops to 0
- Thread starter Craig Burriss
- Start date
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69FBCuda
Stand back 10' for your viewing pleasure & Safety
Could the Pickup be bottomed out? Is it a stock pickup. Pressure valve in the pump sticking? Does the pressure gauge line go thru another fitting, t-pipe maybe? You need to be very careful when using tape with oil and gas fittings one little piece can reek havoc. Are you positive about the amount of oil in the pan(sucking air) Is the oil returning to the pan correctly. In line cooler?
It’s a 440 source pickup and pan, they fit fine when I installed them. I haven’t removed the pump yet, the oil line goes straight from the block to the gauge (I tried two different lines and gauges), I was very careful to not block the ports with any thread tape too. When I drained the oil out it had 6qts. No inline cooler.
Alaskan_TA
Well-Known Member
You already proved the oil pump was working -
Daves69
Well-Known Member
IMO, Anything large enough that gets into the rotor set can stop the pump from pumping (turns the outer and inner as though it was one piece) .......and still not break the pump drive tip off. Had a friend use a block under his 440's sump and damaged his stock pickup screen. We found what we thought was part of an umbrella jamming the rotors.
Rare instances an inner rotor can spin on the shaft if it's only a press fit / no pin.
Take a good look at that drive as well.
Out of the box.....
uncovering a crack in the pickup tube as oil is pumped to the top end.
lifter out of a bore
Rare instances an inner rotor can spin on the shaft if it's only a press fit / no pin.
Take a good look at that drive as well.
Out of the box.....
uncovering a crack in the pickup tube as oil is pumped to the top end.
lifter out of a bore
512Stroker
We are all here because we are not all there.
Well if you primed it with a drill and it maintained 70 psi there is nothing wrong with the oil pump, filter or engine. It must be in the oil pump drive.
Take the distributor back out and start over double/triple inspect everything.
Take your time
Good luck
Nothing is wrong with the pump shaft. I just removed the oil pump and realized that the drivers side of the engine was not even resting on the motor mount, but instead on the pressure spring cap of the oil pump.
The spring cap was not even finger tight. It wasn’t leaking though.
The only thing inside the pump is oil.
I’ve ordered a new spring just because they’re cheap and why not do it while I’m in there. I should probably order a new cap too, and figure out why the engine is riding on it.
The spring cap was not even finger tight. It wasn’t leaking though.
The only thing inside the pump is oil.
I’ve ordered a new spring just because they’re cheap and why not do it while I’m in there. I should probably order a new cap too, and figure out why the engine is riding on it.
Well that is a new one but I can see how that would cause a problem. That nut looks really beat up. You're lucky the oil stayed inside the engine. That could've sheared off and dumped all of your oil on the ground.
512Stroker
We are all here because we are not all there.
That is a problem and needs repair.
I dont understand how that could cause your issue.
Daves69
Well-Known Member
While it's apart, you might take a good look at that inner rotor shaft. Chuck the rotor up between a couple pieces of soft wood in a vice and see if that shaft will spin with a 5/16" allen wrench and a little hurt applied.
The inner on this rotor set out of a Melling M-63 pump I have is pinned.
The inner on this rotor set out of a Melling M-63 pump I have is pinned.
I’ll have to look at that. Thanks.
Damn, you stated that you didn't want to pull the motor again. How many times have you had the motor out? I'm more curious about how it sat in there like that. Must've been banging pretty good.
Probably like 5 times. I wouldn’t really care if I had to pull it again if I had a place to do it. But the car sits on the uneven asphalt driveway with no roof over it. And there’s so many cracks in the driveway it’s almost impossible to roll the cherry picker anywhere. But that’s getting too off topic. I’m guessing it’s my Transdapt motor mounts. I’m not sure what else would cause this.
it’s mostly hitting the lower plate of the motor mount, and barely touches the Kmember
512Stroker
We are all here because we are not all there.
You may have to shim the mounts to correct it.
Daves69
Well-Known Member
Are you leaning toward the mount / relief plug contact causing the pump to fail?
Release that mounts and space it up temporarily to clear the plug completely. Re-test for pressure loss.
Pay attention to your hood and fan clearance!
If it's any use, my 402 pan lowest edge of the lip / K member clearance is 1-3/8". The hood clears the six pack air cleaner on my 69 Barracuda (barely).
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Change the oil pump. Kim
I’m going to try to get a new cap for the pump and get the engine to sit right and then hook up two pressure gauges at the same time to see if it could be something in that back oil passage blocking the gauge. I can’t really go up any higher with the engine because my big K&N air cleaner is about 1/8” away from touching my hood scoop. But I might can play around with the fitment.
I’m not sure what else it could even be.
That’s the only thing I’ve found wrong with anything.
If u change to a stock/high pressure pump will u have clearance cause it is shorter than the hv pump? I still would replace the pump. Kim
I’ve never compared them so I don’t know if there’s a size difference. But if I can do something simple and keep using this pump (only 200 miles on it) I’d rather do that than spend any money, especially in these times.
Ok so I have a theory. These oil pumps basically work like a rotary engine, when they spin, they create vacuum on one side of the “lobe”, and pressure on the other side. Because the pressure relief spring cap was loose, it could have been causing a vacuum leak in the pump, causing the pressure to drop off.
I’ve found the instructions to my motor mount kit on Summit and found that the drivers side mount may need to be trimmed.
So I’ve removed the mount and plan on trimming it. I’ll get a new cap from somewhere and reinstall everything to see if that’s the issue.
Don’t know when I’ll post the results as so many things are shut down right now. I may just reuse my cap if I can’t find one.
I also checked to make sure the inner pump “rotor” hadn’t came loose from it’s pin.
I’ve found the instructions to my motor mount kit on Summit and found that the drivers side mount may need to be trimmed.
So I’ve removed the mount and plan on trimming it. I’ll get a new cap from somewhere and reinstall everything to see if that’s the issue.
Don’t know when I’ll post the results as so many things are shut down right now. I may just reuse my cap if I can’t find one.
I also checked to make sure the inner pump “rotor” hadn’t came loose from it’s pin.
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Nice, hopefully you be back in the drivers seat and off of the cracked driveway from here on out.
yellow rose
Overnight Sensation
I’ve used a couple of this transdapt kits before but I never used the rubber mounts on them. I don’t like the way the mount is forced to hold the engine. I always used the Moroso solid mounts instead.
maddawg57
Member
Craig I had the same problem a few years back with a 71GTX 515 stroker . I did all the stuff that you have done to no avail. So i pulled the engine , 440 source pan and pickup on it also . When i pulled the pan and inspected the pickup n pickup tube i found the pickup tube had a crack in it. Replaced with new pickup tube put it back together and in car problem solved. My symptoms were exactly the same as yours. Sucked having to pull the motor but a relief it wasn't something costly . Hope this helps.
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