no oil pressure need help

[#2875]

ok so i built a 4.3 engine, started it, had insane oil pressure (pegged) at 1000 rpms and it ran like shit. next time i start it there is NO oil pressure. so i pull the dist, hook up my drill primer and pull the lines off of the remote oil filter housing.

when i turn the pump with no lines plugged oil gushes out of the supply line. when i plug the supply line oil runs out of the return line. when i plug both i can feel pressure on both. WTF is going on?

also i don't know if it is related but the fuel pump kicks on when i spin the pump with the drill. has me totally baffled.

can anyone shed some light on my situation?

 

[myclone]

Re: no oil pressure need help

I had more info typed out but I got booted off the interweb when I submitted it...UGH!!

Short version is everything you describe with plugging hoses/checking pressure by feeling the hoses sounds normal due to the way the oil pressure bypasses in the block and oil pump are configured.

If youre using the stock gauge to monitor oil pressure then youre going to be pulling youre hair out. Get an aftermarket oil pressure gauge to verify the pressure readings youre seeing are correct.

The fuel pump turning on once the oil pressure comes up is normal. GM built it that way so that if the fuel pump relay craps out the truck will still start after you crank it for a while and the oil pressure comes up which turns on the fuel pump

 

[bezerk]

Re: no oil pressure need help

i believe it ain''t normal that you get pressure at both ports of the adapter under the block.

there is a plug under the rearmain cap, that devides the deliver and return oilchannel at the filter.
this way,your oil is making it to the cooler and filter, instead of bypassing it.

but like myclone said, get an aftermarket gauge

 

[myclone]

Re: no oil pressure need help

i believe it ain''t normal that you get pressure at both ports of the adapter under the block.

there is a plug under the rearmain cap, that devides the deliver and return oilchannel at the filter.
this way,your oil is making it to the cooler and filter, instead of bypassing it.

Bezerk is correct (dunno what I was thinking :roll: ) in that there is a galley plug in the block that keeps the supply/return from cross feeding. If that galley plug has came loose and moved moved far enough up in its passage due to pressure/improper install it can block the oil feed to the engine but youll get oil pressure out of both supply and return lines to the remote filter.

get an aftermarket gauge

Do the above ASAP and plumb it into the oil pressure port behind the intake so see if youre getting oil pressure there. If youve got oil pressure there then the rest of the motor should have oil pressure.

 

[#2875]

Re: no oil pressure need help

i have an old autometer i'll hook up this afternoon. with the 18V drill turning the pump should i be able to hold back that kind of pressure with my thumb? that's got to be at least engine idle speed or maybe more.

 

[#2875]

Re: no oil pressure need help

where is the plug?

 

[nightdiver]

Re: no oil pressure need help

had insane oil pressure

how much was it ?

The plug Rene talks about is in the first hole , left, as you look the engine form behind , upsidedown :roll: under the main cup

 

[#2875]

Re: no oil pressure need help

it was maxed out, 60 i think. is the plug accessable without pulling the engine?

 

[#2875]

Re: no oil pressure need help

also, since i obviously didn't know what that plug was for what are the chances i botched the install?

 

[bezerk]

Re: no oil pressure need help

normally the don't take the plug out.
you could remove your oilpressure sender unit from the block, and feel with a thin pen.
read the measurments and i can go into my garage and do the same with a block which i know has the plug in it.
if the plug is missing you will get about 3" more measurement.

this plug is really a tight fit, i can't think of any reason why it should move

 

[#2875]

Re: no oil pressure need help

i'll measure tonight. i did a little reading up on this plug. seems to be quite a bit of debate over it. pretty sure mine is in now that i know a little more. i was thinking it was a screw-in plug.

anyway i hooked up another gauge and found out that it was making oil pressure. it still sounds like shit and tries to shut off. not to mention my oil pressure gauge is now just a pretty decoration.

 

[nightdiver]

Re: no oil pressure need help

Lucky you..............my oil pump pick up went off and then i broke a hydro lifter and the pump sucked the little wire that keeps the internals of the lifter in place. The pump gears got some damage and the little shaft that drives one of the gears bended. Then it started eating the pumps housing and finally no oil pressure

 

[bezerk]

Re: no oil pressure need help

my story is much worse.....LOL