What does a failing oil pump act like? Got a Ford 302, and when I cold start it, it's about a full second of no oil pressure. It's long enough that I can hear it make noise. Full of oil on the dipstick, and it's not very old. A warm startup is instant normal pressure. About 18lbs at warm idle, about 45-50lbs at 60mph (3000rpm). Unknown age on the motor, but it doesn't smoke at all, ever, and the plugs are always clean. Never makes any bearing or lifter noise, even at a full stop punch up to 4000rpm. I seem to lose some oil, but not while parked. Lots of mist around the PVC on the valve cover, but it was replaced about a year ago. If that info helps at all. Any ideas??? This is a strong running motor, i'd like to keep it running!
when was the last time you changed the oil? Usually when the oil pump on the SB fords **** the bed, the oil pump drive shaft twists up or breaks, leaving your car dead. Maybe pull the distributor to see if it is starting to twist. It was a recommended replacement item at a certain mileage. If all are good, and new oil does not or did not help, pull the pump and replace it.. Less than a hundred buck fix, or a new engine... easy answer for me. I can help you change it if you want. Also catch up with me on the Mustang.. I need to move it to a different location. Ray
Mine did that, lifter rattle on startup, full oil pressure takes a couple seconds...I changed the oil to 40w70....no more low oil pressure!
my 460 did that...when i got the truck with 91,000 miles on it did that ..still did it with 321,000 on it..i thinks its a ford thing
My 302 in the Falcon gets pressured up before i can get my fingers off the key when i start it ,so im not certain its a Ford thing.Mine was rebuilt about 10 K ago and it runs 40 pounds of presure at a warm idle and 60 pounds on the high way with 10/40 Valvoline .I think you have a weak oil pump or some bearing journals or bearings that are out of spec ...
It could also be the oil filter. They have anti drainback valves. Some of the cheaper ones use cardboard. When they drain, the pump takes a second or tow to refill the filter again. Change it for a Purolator or Pure 1 filter and see if that doesn't help.
As mustangsix suggested, try the filter, it sounds like a drain back problem. My first 302 had about 2-3 psi at idle about 20 at speed. The only time I got lifter noise was when I would punch it, never at startup. I drove it that way for 2 years, toward the end at warm idle the idiot light would flash every once in a while also. I was doing about 60 when I finally lost a rod bearing and ruined every part of the motor. I got another one and refreshed it with new bearings, rings and pump, it ran strong with lots of pressure. After about 5 years I had the pump shaft twist as was described above also, still was a strong motor, but I drove the car home about 2 miles with no oil pressure. Pulled the pump and installed the old one with an old shaft from the previous motor (man I am a pack rat). Started it up and got lifter noise for a short time then had a good runner for several more years. I took the pump apart to see what was up. The housing was cracked. Inside the pump I found what I think was a small chunk of gasket material. I don't remember if I had determined a culprit gasket, but from what I saw I wouldn't think that a bad pump is going to cause the shaft to twist and break. A weak shaft might under load, or a pump that doesn't spin freely might cause it. But from what I have seen when the pump wears out it gets looser not tighter.
The twisted shaft and jammed pump was usually caused by broken valve stem seals or nylon from the timing gears. I've bought plenty of early Mustangs with broken oil pump shafts, put pumps in them with new screens. Would run fine.
I don't mean to hijack the thread. I'd like to avoid any potential problems with my oil system... Can anyone tell me if the 5.0 roller motor uses a high volume oil pump? I've read that the 302 can have a weak oil system and a high volume pump and heavy duty shaft is recommended... thanks
I'm not sure if it's required, but I put a high volume pump and shaft in mine when I rebuilt the motor last year. I get about 40 psi at idle and 60 psi on the highway. Just make sure your valve covers have baffles because those pumps sling a LOT of oil! Besides, they're about the same price as the standard pump, so you might as well. Concerning the original post - I would try the filter first...always try the cheapest/easiest fix and work your way toward more expensive/difficult. I've been using Mobil1 filters recently - pricey, but I like 'em.
Definitely try the filter, but if the problem isn't new to you, take a look at where the pressure pickup is. Might take a second to read pressure even though the pump is pushing.
A full second doesn't sound all that long, really. Many engines are slow to build pressure initially. I don't know that a new pump will help, but filter might depending on the drainback valve found in some...
It's got about 8000 mi on the oil, I was going to change it and the filter here soon, looks like i'll do it real soon. No Fram ever, only Motorcraft or Purolator. I had some distributor problems last summer and switched to a Duraspark 2. I made sure that it matched the shaft correctly. I'll pull it out and see if I can see that shaft out too. Is it hard to get back in? I noticed this morning on a cold start about 50 degrees out, it jumped up to 20lbs before the engine even lit, so it was almost instant. I only notice it when the motor has cooled down to around 100-150, and it's been sitting for about a half hour or hour. Any time shorter or longer, and it's fine. If I replace that pump, a hi-volume is ok then? Glad Meteor asked, I was wondering the same thing!
As odd as it may sound, you're oil may be too 'heavy'. I was getting what I would call a "long light" on startup on my DD. Changed to 5W30 from 10W30 and problem solved. Same brand filter (Pure 1). My theory is that it flows "faster". Who knows, I just know the oil light doesn't come on now on startup.
On the 289/302/5.0 the end of the oil filter is tipped down when its attached directly to the block....most of the oil in the filter can't drain back into the block on these motors. -Bigchief.
8000 miles on an oil change is a lot. Change the oil and install a good quality filter to start with.
SBF's have fine oiling systems (like the SBC) and don't required high volume pumps until you REALLY push the motor (like 500hp/7000+ RPM) and even then its debateable. The only thing a HV pump is good for is drying out the oil pan in a hurry which WILL kill the motor. A good rule of thumb is that you shouldn't run a HV pump without running an oil pan with extra capacity. The pump shafts in these motors are not up to the task and should definitely be swapped out but the stock pump and oiling system in general is good to go. -Bigchief.
I don't think you can swap the pump shaft out from the top - it should have a star washer on it to keep it from coming out (unless it was removed during rebuild). I don't think you have a problem.
Correct....you gotta drop the pan and pull the pump to swap out the OEM shaft with the new one. ...and hopefully the spring clip is still on it before you pull the dizzy, if not you get that aweful pit in your stomach right after you hear the shaft fall into the pan. Argh!
Could be the oil pickup tube(depending on the pan it can be a long tube) leaking down and the pump is loosing it's prime. The tube seals with a gasket. Also if you run any oil additives that have the viscocity of STP they can plug a filter in short order. Sounds like the pump is loosing prime to me. Jeff
Just as a follow-up, a oil and filter change fixed the problem! Never, ever heard of oil or a filter causing something like this, so it's been a education. Thanks everyone, for the input!
i beg to differ i own 7 fox body mustangs all are v8 cars and these 5.0s have terrible oiling systems go buy 3 used small block chevs and 3 used small block fords and compare oil pressure numbers.but let a sbc get below 10lbs of oil press and see how long it last ive got on sbf that carries 5lbs and has for 35000 miles now it just wont die.
Oil pressure & oiling systems aren't necessarily the same thing - by your own observation, the SBF is a better system as it provides proper lubrication at lower pressures than SBC. Glad to hear the problem was sorted...I knew there was no problem!
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