Oil Pressure Gone To *Jeet*

[VBH289]

I need some help, my 289 looses oil pressure and drops well below 20psi sometimes, is that bad? Down the road it is about 30, and I did use thicker oil to help, what should I do?

 

[edjolly]

Check it with a hand held oil pressure gage to make sure it's that low. Do your lifters clatter?

If it is in fact that low, and the 289 pressure specs are similar to the 302, you'll need a rebuild eventually--hard to say how long though. I've heard of guys running quite a long time on engines with oil pressure that low, but I think they're the exception.

Ed

 

[351YJ]

Used to have the same problem w/ my 351W. Cruising it would maybe hit 35psi when hot, and idle it would bounce between 0-10psi. This is with an Autometer mechanical gauge, so it was pretty accurate. I started running a Purolator filter and 10w-40 and that boosted my oil pressure to the good range. Originally I ran a Fram til I started hearing how crappy they are.

 

[Dennis]

Low oil pressure is usually a sign of worn crank bearings.

 

[74bronc]

I am driving around in my dad's 1990 Ch*#y pickup right now and I only have 30psi going down the freeway and about 20 at idle. That's running 20W50 oil in it. Been driving it like that for about 1 year (since he bought it) and 9K miles. The motor has 200K on it and runs strong. The SBF is also supposed to have a better oiling system in it than the SBC. i would run it till it dies but have "rebuild" in your mind or go ahead and rebuild it now.

 

[choppy]

What is considered "normal" oil pressure, (i know this depends on the oil pump i.e. high volume, high pressure, etc.) say for a stock 5.0 efi engine.

 

[ca1a73]

I have the same oil pressure problem....20-25 while driving...0-10 at idle. I tried stp, and 20w 50. I was told it was 99% my bearings. I drive it around town fine, but don't take it over 25miles... It oly chatters when starting up........slight ticking when warmed up.

 

[BoltBuster]

Whats wrong with Fram?

Thats not a defensive question- ;D

 

[74bronc]

[quote author=BoltBuster link=board=5;threadid=15660;start=0#msg118650 date=1048696846]
Whats wrong with Fram?

Thats not a defensive question- ;D
[/quote]

Basically they suck....there are many better filters out on the market. I personally have had 2 Fram failures over the years.

http://www.math.uwaterloo.ca/~rblander/FRAM_recall.html

http://www.frankhunt.com/FRANK/corvette/articles/oilfilterstudy/oilfilterstudy.html

 

[BoltBuster]

Thanks

*runs out side and changes oil and oil filter*

 

[351YJ]

I've just heard of a bunch of Fram failures on EB boards and on the Jeep boards I'm on. Convinced me not to buy another one.

 

[MUDDY68]

Had the same prob. with my 302. It is the crank and rod bearings. (99%) Drop your oil pan and pull a crank bearing out. See if it is "brassy" colored. If so there is your problem. The next thing to do is flip the bearing over and see what the back of the bearing says. Hopefully it will say FORD. Normally, if that is the case your crank has not been turned. Take the bearing to a GOOD autoparts store and get them to get you a set of standard bearings, if your crank has not been turned. While there you should also get some rod bearings. Install all of the new parts and you should see a dramatic difference in oil pressure. It should take you about 4 hours to do the whole job. Just make sure you torque everything back down to spec. Used to run 7 psi at idle when warm now run 38 psi when warm, no tapping. If you need any help or have any questions let me know.

 

[76Broncofromhell]

With a high volume pump and a new motor, I run about 85 lbs down the freeway and 70 lbs at idle with 20w-50 and an FL1 Motorcraft filer. I would say you OP might reflect on the necessity of a rebuild in the near future.

 

[tcjones76]

[quote author=MUDDY68 link=board=5;threadid=15660;start=0#msg118819 date=1048735691]
Had the same prob. with my 302. It is the crank and rod bearings. (99%) Drop your oil pan and pull a crank bearing out. See if it is "brassy" colored. If so there is your problem. The next thing to do is flip the bearing over and see what the back of the bearing says. Hopefully it will say FORD. Normally, if that is the case your crank has not been turned. Take the bearing to a GOOD autoparts store and get them to get you a set of standard bearings, if your crank has not been turned. While there you should also get some rod bearings. Install all of the new parts and you should see a dramatic difference in oil pressure. It should take you about 4 hours to do the whole job. Just make sure you torque everything back down to spec. Used to run 7 psi at idle when warm now run 38 psi when warm, no tapping. If you need any help or have any questions let me know.
[/quote]

My 302 has the same oil pressure issues, and you are saying that I can change both crank and rod bearings from under the truck thru the oil pan? Any clearance issues I need to worry about?

 

[Broncobowsher]

Depends on how hard you run it. My parents had a small block that would idle at around 10 and cruise 20 to 25. It ran for 100k+ and never had a problem. Sold it that way. The lifters didn’t tick. It got some workouts. It would tow the boat and family through mountains. Hauled me and all my stuff to and from school. I last used it to move I ½ filled it and it was sitting on the bumpstops. I then finished filling it and the oversized tires would squat like they had 10 PSI in them. Never left the bumpstops for 120 miles, except for 1 cloverleaf. Never hurt the motor. Also never raced it. I don’t think that engine ever saw over 4500 RPM in its life. The Vehicle was an ’84 econoline with a 302.

If it ain’t clattering and you don’t plan to race it. It will probably live for a long time. Pick up a 351 and spend a year piecing it together.

 

[supermottl]

How would one get the upper halves of the bearings out with the crank sitting there???

 

[Dennis]

You drop it. Replace rod and crank bearings. Although I've heard of people carefully sliding the old ones out without undoing the rods. I've never tried it myself.

 

[74bronc]

[quote author=Dennis link=board=5;threadid=15660;start=15#msg118950 date=1048786635]
You drop it. Replace rod and crank bearings. Although I've heard of people carefully sliding the old ones out without undoing the rods. I've never tried it myself.
[/quote]

I just pull the motor out and do a quickie on it...oil pump, bearings, seals etc. Much less of a PITA if you have the means

 

[Dennis]

And thus starts that neverending spiral that sucks us all in. If I'm gonna do this, I may as well do that while I'm at it. If I'm gonna drop the pan, I may as well do the bearings. If I'm gonna do bearings, I should just slap some new rings in also. If I freshen up the bottom, I mayas well do the heads. If I do the engine, I should do that tranny swap at the same time. The engine and tranny are out, no time like the presant for that new atlas.............. It never ends. You better look for a new job now.

Seriously, drop the pan and replace your bearings and your oil pressure should come back up. If you can afford it, freshen the whole engine up.

 

[Rustytruck]

If you start your engine and let it get to water temp and look at your oil pressure guage and then Drive the truck for an hour and the pressure gets significantly lower then it is probably your bearings if the pressure still reads about the same then try changing your oil filter brand. I read all of the reports on oil filters and differences on the way they were built and looked at what I was using and what was easily available to me and made a change. I use to you use fram and changed to a motorcraft and my pressure raised more than 10 PSI especially at freeway speeds. My engine is the same one the was put in the truck from ford and has never had the pan off. I run 20-50 Valvoline oil. Watch out for funny oil pressure readings with Casterol oil it is a good brand of oil but reacts to viscosity changes very rapidly which is why they like it in 4 cylindar engines and motorcycles. But your oil pressure guage readings will drive you nuts. If your lifters and valve train are not clacking and you have some oil pressure at freeway speeds you will be fine for a very long time. Of course if a cheep pulls alon side and you want to prove your metal you are on your own. I've seen babbied pieces of sh*t last forever and expencive built engines blow at the touch of a hat.