74 dart project

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Dallasfromdallas

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Sep 29, 2019
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Dallas Texas
Hey there everyone I just acquired a 74 dart swinger. Description is in my signature. But the engine is suffering from low oil pressure. I bought this car to learn how to work on cars for myself and I already have a few books on the way about small block mopars, a bodies in general, and some others. Really just posting this to see if anyone can help me with this low oil pressure problem. Thanks!
 
Please define "low". Is it low at idle, all the way thru the RPM's. Have you tried a different gauge? Changed oil and filter? Is pressure low at operating temperature or all the time?
 
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I’ve tested it with multiple gauges yes. And after start it’s around 15-20 psi and after warming up it lies around 5 psi. Haven’t changed oil or filter yet as I haven’t had the time too. Will maybe try that first. Just trying to get an idea of what I’m working with. As I said this is my first classic car and I bought it to learn on/make a daily driver
 
That's pretty low, do you know what weight oil is it? How many miles are on the bearings? Any noise/rattles at start up?
 
No rattles Or anything starting up. Just sounds really sluggish. Sounds out of time to me (not 100% sure it’s un-timed that’s just my untrained ear) i. Also have no knowledge of oil weight. The gentleman I bought the car from said the engine was freshly rebuilt. Hadn’t driven it at all so no miles on the bearings. I’m thinking he may have put in the wrong bearings?
 
Well the no rattles is good. Incorrect bearings could be a possibility, but just guessing, I would think their would be a little noise. Freshly rebuilt? Now we may be getting somewhere... I don't know where all are located, but I know their are a few plugs that must go back in the block, or you will end up with low oil pressure. The search function will come in handy for this, but hopefully someone who knows more will pop in.
 
In the meantime, for ***** and giggles, I would grab a new filter and some decent 10w-40 and see what happens.
 
Sounds like a typical worn out engine with bearing clearances worn beyond their service life. I don't want to be the bearer of bad news, but I have been there two or three times and tried new bearings, oil pumps and thicker oil to no avail.

The real solution is to rebuild the engine, turn or polish the crank, new bearings and new oil pump.

Left alone expect it to get worse and progress into a rod knock.
 
Might have to check out those plugs and make sure they’re all in there. That is a possibility. And I work all weekend but when I get back in the shop I’ll swap the oil and see if anything changes
 
d55dave said:
Sounds like a typical worn out engine with bearing clearances worn beyond their service life. I don't want to be the bearer of bad news, but I have been there two or three times and tried new bearings, oil pumps and thicker oil to no avail.

The real solution is to rebuild the engine, turn or polish the crank, new bearings and new oil pump.

Left alone expect it to get worse and progress into a rod knock.
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I’m not running or driving the car so it won’t develop into anything... the engine is freshly rebuilt with a machined crank, bored .030 over.. how could the bearings be worn beyond their service life if they haven’t even had a life. The engine has maybe 500 miles on it
 
Dallasfromdallas said:
I’m not running or driving the car so it won’t develop into anything... the engine is freshly rebuilt with a machined crank, bored .030 over.. how could the bearings be worn beyond their service life if they haven’t even had a life. The engine has maybe 500 miles on it
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Sorry, didn't realize it was a fresh engine. If it is a backyard rebuild it could still have an undersized crank, and worn out cam bearings. You should probably drop the pan, look at the oil pump and check the condition of the crank journals and bearings.
 
d55dave said:
Sorry, didn't realize it was a fresh engine. If it is a backyard rebuild it could still have an undersized crank, and worn out cam bearings. You should probably drop the pan, look at the oil pump and check the condition of the crank journals and bearings.
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Okay sounds good. I’ll post again when I can get into the shop and get some work done. For now back to bartending. Thanks everyone
 
So a little update. Haven’t been on the site in a while but I got around to checking out the valve train and noticed that there is an insane amount of clearance on all of my rocker arms. Both sides of the engine. Anybody have any ideas as to what could cause this? And is this a possible source of low oil pressure?
 
Not sure about your rocker arms, but I had a similar issue with a 360 that had low oil pressure. I installed a high volume Melling pump and it's got great oil pressure now. Maybe a standard oil pump would be fine too but I really do believe oil pumps need replacing sometimes. Of course a full tear down is great but sometimes its just not in the budget. Good luck with your car!

Cley
 
89on35s said:
Not sure about your rocker arms, but I had a similar issue with a 360 that had low oil pressure. I installed a high volume Melling pump and it's got great oil pressure now. Maybe a standard oil pump would be fine too but I really do believe oil pumps need replacing sometimes. Of course a full tear down is great but sometimes its just not in the budget. Good luck with your car!

Cley
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The guy I bought it from installed a high pressure/high volume pump, Not sure if it was a melling pimp though I’ll have to look at the receipts he gave me. And as far as a full tear down goes, I really hope it doesn’t come to that as the engine basically was freshly rebuild by the previous owner. I’ve got a big stack of receipts for it. But i really have no idea if it was PROPERLY rebuilt. Thanks for wishing me luck! I’m going to need it chasing after all of the loose ends on this car. Need to get the engine running right so I can at least drive it before I start worrying about all the wiring issues under the dash
 
"The gentleman I bought the car from said the engine was freshly rebuilt. Hadn’t driven it at all so no miles on the bearings. I’m thinking he may have put in the wrong bearings?"

The block has been bored.
So when they went to rebuild this did they put the plug in the driver side rear oil galley? That will make for major low oil pressure and is a common mistake that is made.

Another thing that you need to look for is was the oil pump mounted flush to the rear main cap. This is something that is also sometimes overlooked. If there is no gasket make sure that both surfaces the one on the pump and the one on the main cap are completely flat so that they seal. Personally I use the gasket between them.

Your lifters are not pumping up because your oil pressure is so low and that's why you're having so much play on your rocker arms.

I would pull the distributor and the intermediate shaft and run a primer rod down in there and spin it with a drill and watch what's your oil pressure gauge does then. Pull the valve covers an watch as you slowly rotate the engine.
Also check underneath the oil pressure sending unit down about seven and a quarter inches and make sure that they put that plug that diverts the oil flow to the filter back in.

I would NOT start this engine up and let it run until I find out where my oil pressure is.
 
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I will definitely contact him and ask about the rear oil gallery. And correct me if I’m wrong but I believe the engine has solid lifters in it which wouldn’t be affected by low oil pressure..? I definitely will pull the pan off and check the oil pump mating surface at some point. And I have already cranked the engine with the distributor plug off to check clearance on the rockers and every single one has clearance it shouldn’t have. Is there a possibility the rods could be too short? Would adjustable rockers fix this problem? Sorry if my questions don’t make any real sense. This is my first engine to really get my hands on and work on so I’m learning all of this for the first time. Thanks for the help
 
If the engine does not have adjustable rocker arms on it then it has a hydraulic cam in it.

Is this engine under warranty by chance?
 
Even a garage will sometimes have a warranty.

If you have one of those little cameras that you can hook to your cell phone and and run the camera inside the motor. You would pull the distributor out and run the camera over to the back driver side and see if you can see a plug in that oil galley.
 
Jadaharabi said:
Even a garage will sometimes have a warranty.

If you have one of those little cameras that you can hook to your cell phone and and run the camera inside the motor. You would pull the distributor out and run the camera over to the back driver side and see if you can see a plug in that oil galley.
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Haha I meant in the guys own garage not a shop. My bad. And I contacted him and he said that the plug was put back in
 
Personally I would check it anyway if the shop took it out that board the motor he may not even know what you're talkin about.

Now if you're getting oil to the rods the oil pressure should still be up because it's being fed by the main galley but if your gauge is wrong then it could be the number two and number for cam bearings are not lined up correctly to oil your rocker arm assemblies but that would not affect your lifters pumping up.

I would check that plug on the driver side oil Galley and I would check that the oil pump is mounted flat on the rear main after I check to see that the plug is in it. And if you take the oil pressure sending unit out and stick a rod down the hole, it should go down approximately 7 and 1/4 in and stop if it goes beyond 7 and 1/2 in, that means that plug is not in there. And you have to remove the rear main cap in order to put one in it.
 
Btw there is also a plug at the back of the passenger side oil galley. You need to make sure it's in there too.
 
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