Projects HELP! SBC Oil Pressure is going HAYWIRE!

I'd be checking the bearings when I pulled the pan and a set of new bearings doesn't cost that much nor take that much time to change while you are at it if they look the least bit suspect.

Along with inspecting the oil pump and pickup tube as you originally intended.

 

Fram filter on a Chevrolet should not cause a oil pressure drop the bypass valve is in the motor not the filter. Most of the problem with Fram was the bypass valve not closeing rendering the filter usless.

 

frams worst issue a collapsed filter element that caused a catastrophic failure due to loss of oil pressure.

 

Here's some helpful filter info.

http://mechdb.com/index.php/Oil_filters

 

when you have the pan off pull the center main and look it over real good. Dirty Old Man has a point about main bearings. Probably not but it can't hurt to check while you are in there.


Tim

 

Scruffy, just a thought, regardless of brand of filter you have, might cut it open and see if the interior reflects what you found on the drain plug. An old GI can opener, available at most sporting goods store...in the camping stuff, will open it without adding any debris. It will give you a better picture of whats inside. As far as the galley plugs, if they came out, your pressure would always be in the shitter, but if you have to tear the engine down, it would be good to stake them anyway. Out of reading all this, I think the broken spring sounds like the most viable option, buy yeah, ditch the fram if you are using one...

 

Sorry but this ain't my problem.

 

I guess you are gonna drop the pan some day, let us know what you see.....

 

overfill by 3 qts . if it's fixed, your pump pick up has fallen off. that's the easiest way to check that

 

debris of some sort in the oil pressure gauge and or line?..... Seems checkin the easy stuff first would be the way to go on this and i've seen cheap oil pressure gauges do some strange things, both mechanical and electric types.

 

Ok, I know I took long enough, but things have been a little busy. I dropped the pan, which required removing the front crossmember and undoing the front brake lines, and undoing the exhaust to raise the engine far enough to clear the mounts.

Pulled the pan, and the mains. Mains looked good, found very little crud in the oil/ pan. I am kinda embarrased to say what I found in the oil pump, but here it goes. There was a plastic spark plug wire seperator in the pickup. Must have fallen in there as I pulled the dist a couple of months ago. It definitely went down there with the dizzy out, as it was not even scuffed up. Changed the oil pump anyways, just took it for a cruise, and seems to be doing fine.

I will be cutting the filter open sometime just to see what was in there. And no, it is not a Fram!

 

Haha, it's not like none of us have ever done anything like that ! Glad you found it was something simple. Happy motoring.

Don

 

Thats funny now that you know you didn't do any damage.. To this day i have a flat blade bit rollin around my pan from when it fell off the extension i was using to pre-oil.... I figure its small and heavy so maybe it'll come out someday during an oil change.

 

A long time ago, my dad told me to ALWAYS cover any open holes.
If I didn't boy would I get the lecture. I figured I didn't need to cover them all of the time.
Now I make sure open holes are covered. Not because of the lectures or years of experiencemy dad was passing down, but because when I didn't cover them shit falls in. Cost me plenty of time getting them out.
Turns out as a younger man my dad had a few things fall in that cost him dearly.

This is the kind of thing that you hear a million times but don't always listen too until it costs you.
Glad you found it early.

Now you are one of the experienced who can say cover the open holes.

 

Glad you found the problem, and I'm glad it wasn't the main bearings I suspected.
Dave

 

Thanks for the help everybody!

@ 31 Vicky: I had covered everything up, so the only chance I had to drop it in would've been when I pulled the distributor! I have been preached the same lesson, and this may have been the first time I listened. Haha.

The flat screwdriver bit reminds me of a story that my grandfather, a career shadetree mechanic, told me. A neighbor had bought a 1979 F100, brand new, and had always brought it to him for oil changes. While it was still under warranty, the owner noticed a rattle and took it, repeatedly to the local Ford store, only for them to find nothing. Once, during an oil change, my grandfather dropped the pan and found a 3/8 bolt laying in the pan, rounded off on all sides from dancing around in the bottom of the motor. Apparently Ford built it that way!

 

HAHA a spark plug separator. Good for you.
I worked in a shop with this idiot "Master engine super wrench, do it in his sleep, already forgot more than you'll ever know" type of high hat dude. He left a red mechanic's rag in the pan of a 389 the owner was putting in his 64 Catalina. Started it up, ran great. Got it on the freeway and the rag came out from under the windage tray. Destroyed. I got to tear it down because I was the FNG and I could learn from the tear down. Mostly I learned put your own stuff away.

 

Just remember to take the red rags out of the intake before putting the carb back on..............seen the aftermath of this twice...not good either time

 

Good one. I have learned alot from working in powerhouses and chem plants, especially turbines. Everything gets a cover, take off your ring and watch before you take anything apart.

I can already see where this thread is going. Can we re-title it "Dumb Shit I Dropped In My Motor?
"

 

I bought a 66 GTO convertible from a buddy one time because he was tuning it up and had replaced the lost carb wing nut with a square hardware store nut. The aircleaner was off, the motor was running, and he was screwing the nut back on the stud when it fell right into the carb. Before he could shut it off it had swallowed it and noise and smoke started coming out of the engine.

In frustration he told me I could have it for $ 800 bucks so I bought it. When I tore the head off there was a perfectly punched square hole in the top of one of the pistons, it looked like a machine had punched it there. I think a new piston was something like $11 plus a few gaskets and rings and it was back on the road, good as new. It was a 4 barrel Goat and ran as quick as my tripower one and sure cost me a lot less.

Don

 

X 2 Seen this myself also,this is my quess ,if the pick up tube fell off you would have to add 5 gal of oil for it to get any oil and it wouldnt be up/down ,just be zero. Also ive never seen one suck air that wasnt low on oil or driving normal.good luck let us know.

 

Congrats,should of read the rest of post before posting,see i learned something too.I had a simular thing in a fuel tank from a pack of matches that was put in the gas tank.Only had problem when i guess i stirred it up when filling up.............YG

 

It is interesting that GM built millions of sbc's with pressed in oil pump pick up tubes that didn't fall out Now it seems stupid not to weld or, mechanically secure them in.

 

Glad you got your situation fixed!....I've seen some similar things happen to Small Block Chevy’s....low oil pressure problems. Spun cam bearings, rear cam bearing not installed far enough to cover groove. Oil galley press-in plugs popping out....in the front and under the rear main cap. Cracked main webs......all doing what you describe. Reading this reminded me of a carb wing nut story!...sharing a garage with a asphalt racer....lost his carb wing nut! Did you see my baseball? (wing nut)....nope!....he started it up!...TING!....BANG!....PING!....I yelled over the noise " I FOUND IT! "

 

Glad it was an easy fix.

COMMENT: It's funny how many times I see posts from people who OBVIOUSLY do not read the entire thread before posting. This is definitely one of them.........

 

I don't think the plastic piece in the pickup was the problem though. I am thinking the problem was the relief valve in the pump sticking or broken spring as mentioned before. So you did good by replacing the pump.

wrenchn
Unless it was big enough to cut the flow down

 

My thought was that I was seriously reducing my risk of having to drop the pan again by replacing anything in the system that I could not guarantee was good. Melling hi-vol oil pump, pickup, and shaft was less than $40. You wouldn't pay me $40 to pull that motor again!

 

Main bearings. Goose it, the pressure pushes the crank downward from the extra load, oil pressure drops, let off, less pressure, crank is pushed upward, oil pressure rises.

 

I see you have 48 posts Eric, not trying to stir shit, but I suggest that you read all the posts before posting on a thread.
Way back in this thread I posted the same theory as yours, but the OP has pulled pan and checked mains and says they are OK.
I can accept his diagnosis of clogged oil pickup tube although I have to be puzzled as to how that pluq wire seperator got inside the pickup tube unless he was running without a screen on the tube!
Dave

 

Fixed it.