I been having some issues with my motor. I rebuilt it with a new crank bearings rings stock rods pistons. The issue was after the rebuild the valves was noisy. After a while I noticed my oil pressure would drop to almost 0 after warmed up unless you revved it. Like a dumb ass I reused the old oil pump didn't change the cam bearings or lifters. So I was hoping it was the oil pump and lifters or push rods cause I didn't mal which way they came out. So I just went to the junk yard and got a set out of a explorer making sure everything was in order. Put the new pump in. Installed rods lifters rockers. Started it and still noisy as hell. The oil pressure at idle was 25 psi. I noticed when I revved it the oil pressure stays exactly the same! Wtf. I pulled the valve cover while running on pass side and no oil was coming out the rod into the rocker. After I let it run for about 3 mins or so like 3 had very little oil coming out which I'm assuming is why they're noisy as hell. Just wondering if anyone had any idea what might be causing this. I've read online people having a similar issue as far as oil pressure staying the same and it was there filter. Never had a issue with fram filler. Which is what I'm using. Any suggestions?
Engine oil pressure issues
- Thread starter mr2gq
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So you put a used set of lifters and pushrods in the motor? Was the oil pump new or used? Fram filters are the worst BTW. Look for pics of a fram vs a motor craft there is no comparison as far as quality.
mikestang63
SN Certified Technician
Buddy, not to beat you up by WHY would you go through rebuilding a motor and cheap out on the most important piece- a new $30 oil pump? Also, did you reuse the old cam- trying to figure out why you reused the lifters and pushrods. You took out the old oil pump and installed a JY one along with JY lifters and pushrods? Your post is very hard to understand.
Fram filter? Were your cam bearings scored/nicked/worn. What about the rod and main bearings- New? used? Did you measure tolerances and fit them?
Low oil pressure could be from a number of things, but from the start it sounds like you have many issues already that are contributing to the problem. How many times do you want to rebuild this motor. Just do it right the first time and be done with it. New oil pump, lifters, pushrods, a good filter like Wix or FL1A.
Fram filter? Were your cam bearings scored/nicked/worn. What about the rod and main bearings- New? used? Did you measure tolerances and fit them?
Low oil pressure could be from a number of things, but from the start it sounds like you have many issues already that are contributing to the problem. How many times do you want to rebuild this motor. Just do it right the first time and be done with it. New oil pump, lifters, pushrods, a good filter like Wix or FL1A.
Lifters rarely go bad, unless you add quite a bit of rpm to the setup, there is nothing wrong with reusing them.
Cheaping out on the pump, well not such a great idea, although oil pumps usually work or they don't, and they really aren't known for failing although people here seem to think low oil pressure is because of a worn pump, that's almost never the case.
This is why i tell people instead of messing with rebuilding a 302, just buy a $500 explorer engine. At this point your rebuild may be so screwed up, an explorer 5.0 still may be a viable option.
Cheaping out on the pump, well not such a great idea, although oil pumps usually work or they don't, and they really aren't known for failing although people here seem to think low oil pressure is because of a worn pump, that's almost never the case.
This is why i tell people instead of messing with rebuilding a 302, just buy a $500 explorer engine. At this point your rebuild may be so screwed up, an explorer 5.0 still may be a viable option.
Sorry. I bought a new crank kit. Came with the correct rod and main bearings. All brand new. The cam bearings looked ok. They wasn't down to the copper or scored or anything. Si I didnt want to take it to a machine shop and have thrm put in the cam bearings. I just bought a used set of rockers push rods and lifters. Bought a BRAND NEW. Oil pump and installed everything and now its having the issue I described previously. It was falling to 0 after ran for a min and would move when revved. Now its just staying around 24psi. I used the old pump cause it felt tight and new from previous owner. Also as I said I been reading where people have the issue with pressure stsying constant after changing oil and filter then they put a new filter on and fixed it. My luck is pretty slim so I doubt that's my case but im going to replace the fram with a motor craft
ratio411
Founding Member
The only problem I see outright is reusing the old oil pump.
I make it a habit to replace oil pumps in old engines when they ever come out of the vehicle, or if I buy a salvage engine to install... I would never consider reusing one. That said, it's unlikely to be your problem, assuming it was reinstalled properly.
The issue you are having could be any one of a million oversights or errors on your part, and/or one of dozens of parts failures due to cheap parts or mismatched parts. It's almost too much to list.
Personally I wouldn't really suspect cam, cam bearings, pushrods, or lifters.
I would bet on something eles, such as failure to check bearing clearances and endplay.
It's also possible to have left a galley plug out or loose.
Fram filters are poor quality. I am not saying that is your issue, but they are known for having substandard internals.
Good luck. I hope it's something simple.
I make it a habit to replace oil pumps in old engines when they ever come out of the vehicle, or if I buy a salvage engine to install... I would never consider reusing one. That said, it's unlikely to be your problem, assuming it was reinstalled properly.
The issue you are having could be any one of a million oversights or errors on your part, and/or one of dozens of parts failures due to cheap parts or mismatched parts. It's almost too much to list.
Personally I wouldn't really suspect cam, cam bearings, pushrods, or lifters.
I would bet on something eles, such as failure to check bearing clearances and endplay.
It's also possible to have left a galley plug out or loose.
Fram filters are poor quality. I am not saying that is your issue, but they are known for having substandard internals.
Good luck. I hope it's something simple.
Okay maybe someone can in lighten me. I go home change oill filter unhook the aftermarket electric gauge and put mechanical gauge on start it up and now it's reading 0 oil pressure. Idk if the electric one is messed up or what. Take the distributor out turn it with the drill oil pressure shoot up to like 45psi or so drill maxes out at 2500 rpms. Lifters fill up oil comes out every where. Put distributor back in crank it up and it's still reading 0 pressure. Wtfff?? Can anyone tell me why it's getting pressure with the drill but not being turned by the distributor??
Ok, did you check your main bearing clearance on the new crank? How about lower rod bearing clearance? How worn are the cylinders? How worn are the old cam bearings? Old oil pump? How did the crank endplay look after installing new bearings? Measurements?
No didn't really check clearances. Just installed perbook instructions. Like the number 3 main bearing. It was a complete crank kit. And what about the old oil pump, I just put a new one in? Already described cam bearing. And the end play was fine. The cylinders looked fine as well. Hardly no ring at the top and could still see crosshatch
Yes sir I made perfectly sure double checked all bearing were installed properly and that the bearings with oil passages went to the corresponding side. Makes no sense to me it will get prefect pressure with a full but when running shoe none at all. I check the shank on the dis and it's fine.you can clearly see the shank on the oil pump is high enough to meet shank on the dis. It's a brand new dis. And If the cam wasn't turning the dis properly it wouldn't run right. But it runs perfectly fine
Possibly the wrong size shaft? There is a size difference in oil pump shaft size from 302 to 351. Just thinking?
mikestang63
SN Certified Technician
Considering no clearances or tolerances were checked, we are all stabbing in the dark here. Did you reuse the old pickup screen and tube and if so did you get it squeaky clean. Did you put any RTV on the oil pump base or just the gasket/o ring? Did you also test the oil pressure sending unit?
My guess at this point is either the bearing/camshaft tolerances are out of whack, a faulty/stuck/clogged/ oil pump pressure relieve valve, a leaking oil pump pickup tube or oil pump.
My guess at this point is either the bearing/camshaft tolerances are out of whack, a faulty/stuck/clogged/ oil pump pressure relieve valve, a leaking oil pump pickup tube or oil pump.
ratio411
Founding Member
You turned the pump with a drill and got oil pressure.
When the engine runs though, no oil pressure.
So there is an issue with the distributor.
Is the hex rounded out inside the distributor.
The end of the shaft is bascially a socket turning the hex head.
Sockets can crack and/or round out... hex heads round off.
When the engine runs though, no oil pressure.
So there is an issue with the distributor.
Is the hex rounded out inside the distributor.
The end of the shaft is bascially a socket turning the hex head.
Sockets can crack and/or round out... hex heads round off.
Yes it gets pressure when I pull the dis and turn with a drill my drills Max rpm is 2500 and I get over 45psi. Ive pulled the dis 3 times and did this. My tool I use to prime pump fits the original oil pump shank as well as the new oil pump shank. So they are the same size. And I took the old shank and got it into my new dis nice and tight. So I don't think my dis is broke. Thanks for the replies
I pulled dis this am before work real quick. Its not rounded. Put the old oil pump shank just barely in the tip ,just incease its nit going down real far, and it's nice and tight. Also again my tool im using on the drill fits the old shank and new shank. So t they're not different sizes. I'm going to pull the gear off the dis, put the dis back in with out the gear and see if I can turn it with my drill just to make 100% sure it's making contact with the oil pump shank
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