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2002 Silverado 5.3 - oil pressure problem

K5_Fla

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Location
FLORIDA
2002 Silverado 5.3 - 160K miles.
Issue –

Started the truck today and the oil pressure was at 0…. Warning light came on saying low oil pressure. Shut it down… waited a second and restarted… pressure “caught” and went up to normal. Drove the truck as normal, but it oil pressure seemed to move around more than normal. Got home… Stated it back up.. same thing keep happening….0 and then I give it gas and it catches… goes up to 40-60psi.

Someone told me a check a few things.

1.Change the oil filter….it could be collapsing. ( even though I just changed oil and filter a month ago) I got a new oil filter… will be changing as soon as the truck cools down some.

2. Something about a O ring on the plastic pickup tube?? Can someone explain this in detail? How to do it? Part number needed?
 
There is a oring on the pickup tube that goes into the oil pump. The pickup is metal not plastic all you have to do us drop the oil pan to replace the oring.
 
I changed the oil filter... no dice. I guess the issue is that o ring. How hard is it to drop the pan and get to it?
 
Had an issue here not long ago with the '05 5.3 in the Avalanche, it would always read pegged out, max, but if you got on the throttle and got the motor revving, the pressure gauge would just drop to zero and set off the dash bells.

I replaced the oil pressure sensor on the back/top of the motor, all has been fine since.

Be the first place I would cheack really before pulling pans and all the hard work.
 
Yep, like he said. I was going to suggest you check it with a mechanical gauge or a different sending unit, but I got sidetracked on another thread.

One thing you can try. Turn off any noise makers. Fan, radio, and let the engine idle for a few seconds with the 0 pressure.

Unless you have a modified high RPM motor with solid lifters, you are going to start hearing a clatter fairly quickly if you really do not have any pressure.

Hydraulic lifters must have some oil pressure to stay pumped up. If they lose pressure, they collapse and put lots of slack in the valve train resulting in a clattering noise.
Doesn't hurt anything, they pump right back up when they get oil again, but it is a definite sign you have lost pressure.


Heck, before you even do that, check the wire going to the sender unit. It sounds like it just might be loose.
Or the little resistor inside the sender has gone bad on the lower end of the scale. So that it does not start reading until the pressure gets up to about 40 or so.

Of course, running it long without pressure will start to damage things, but it normally starts with no pressure and relies on the oil film to keep things lubed until the pressure builds up.

That is why I have always wanted a preluber to build up pressure on my engines before I cranked them, but never got around to buying one.
 
I would verify that the gauge cluster is not faulty. VERY common on these. Does the computer read the oil pressure and turn on the indicator, or does the gauge cause that? I have seen Faulty clusters showing no gas, gas light on, hit the dash, or drive a bit and it goes back to normal, gas light off.
 
Here's A video I took back when I had issues with this one here.

Still, I'd be replacing the sender really, I know they aren't really cheap, but much easier to rule out with a new one, easier to replace than the work involved dropping a pan and even then possibly realizing THAT wasn't the problem.

 
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From my research it seems the sender issue is related to erratic high pressure readings. Anyway.. I changed the oil filter yesterday and initially there was no change. However… today I started the truck up and worked just like it should… immediately had oil pressure. I drove around for a while and everything worked like it should. I shut down a few times and started it back up… worked great. Looks like it was probably clogged or something and it fixed itself???
 
yes... somthing else.. i detailed the truck today.. cleaned the engine bay, etc. I wonder if I moved a certain wire... .because it started running right after I cleaned the truck. Maybe the truck was just happy because it hasnt been washed in a year.
 
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