No oil pressure at idle

[96redchev]

So I have a 96 5.0 with 226k I just replaced the oil pressure sensor when idling at operating temp it says check gurgles shows no pressure I idle at about 650 700 if I bump the throttle to take it to 1000 I have about 15 to 20 psi running down the road at 70 it’s steady at 40 I don’t know if the sensor is tight,loose,faulty im at a loss it recently skipped time something terable so possibly did something when that happened it’s made no noise tho changed oil today and maybe 15 specs of metal on the plug magnet

 

[GoToGuy]

I would get a mechanical known good gauge, plumb it in and verify what is actually going on, pressure wise. Factory spec is no less than 6 psi hot at idle. You may have a bad transmitter,. Do you have low oil press light?

 

[96redchev]

I would get a mechanical known good gauge, plumb it in and verify what is actually going on, pressure wise. Factory spec is no less than 6 psi hot at idle. You may have a bad transmitter,. Do you have low oil press light?

Yes once I come to a stop of let it idle in park the light comes on

 

[movietvet]

I hate assuming but did you replace the sensor because of what? Light was on and replaced and light is STILL on? Clattering knocking noises? Pics of the 15 specs of metal would be good. You actually could be losing enough bearing material that you don't read good oil pressure till off idle. BUT, at idle you should likely be hearing noises or will real soon. Like @GoToGuy said, get a gauge on it, not on the dash gauge, and see what is actually there.

 

[96redchev]

I would get a mechanical known good gauge, plumb it in and verify what is actually going on, pressure wise. Factory spec is no less than 6 psi hot at idle. You may have a bad transmitter,. Do you have low oil press light?

Yes once I come to a stop of let it idle in park the light comes on but

I hate assuming but did you replace the sensor because of what? Light was on and replaced and light is STILL on? Clattering knocking noises? Pics of the 15 specs of metal would be good. You actually could be losing enough bearing material that you don't read good oil pressure till off idle. BUT, at idle you should likely be hearing noises or will real soon. Like @GoToGuy said, get a gauge on it, not on the dash gauge, and see what is actually there.

so when it jumped timing( was not aware it was out of timing when this occurred ) I lost all pressure and parked it immediately. I assumed the sensor was bad since it is the original. no bad noises. But the bearing on the bottom pulley is beginning to make some noise. The light only shows up when the motor is warm and it’s at a stoplight or when idling in park

 

[movietvet]

Bearing on bottom pulley? You mean the front crank bearing? How do you know it jumped time? Pics of the metal on drain plug, or did that get thrown away? If you have bearing material showing up, then oil pressure can be effected and then noises and then kaboom....

 

[96redchev]

Bearing on bottom pulley? You mean the front crank bearing? How do you know it jumped time? Pics of the metal on drain plug, or did that get thrown away? If you have bearing material showing up, then oil pressure can be effected and then noises and then kaboom....

Yes that’s what I meant unfortunately I threw it away the metal was extremely fine. I figured out it jumped timing when I went to replace the sensor and the entire distributor assembly came strait up part of the plastic ring was snapped off in return it was refusing to turn over I have two yellow top gel cells in it so I knew that wasn’t the cause and the starter teeth looked fine

 

[movietvet]

I am sorry, I am completely confused. can you supply pics? Threw the bearing away??????

 

[11bravo]

I believe it was the plug he was referring to that had the shavings on it, and maybe he cleaned it up. Hard to follow all of this.

 

[1998_K1500_Sub]

I figured out it jumped timing when I went to replace the sensor and the entire distributor assembly came strait up part of the plastic ring was snapped off in return it was refusing to turn over...

IIRC 1996 and certainly later engines used a crank trigger to control the timing, so I can't fathom how the timing ever "jumped"... unless the distributor somenow got turned SO far out of spec that the spark was jumping to the wrong tower in the cap (and thus firing the cylinders with grossly advanced or delayed timing).

Otherwise, distributor only plays a subordinate role.

See https://www.gmt400.com/threads/98-5-7-k2500-timing.66119/post-1386186 and the posts there.

I assume the "sensor" you mention here is the "oil pressure sensor".