Timburnswood

Hey everyone just did head gaskets on my 2000 Silverado 5.3l went perfectly good enough. Was hoping the blow head gasket was why I had low oil pressure. Which the coolant getting into the oil and all. But.... didnt help at all checked with a mechanic gauge had 10psi at the oil sending unit at a cold start with 5w-30 fresh oil. Not good. Today I dropped the oil pan and found some junk clogging up the pick up tube. Fix the oil problem right? I wont know if I have pressure until tomorrow gotta get the gasket and o ring. Any input on the sizable amount of metal shavings? Being that I had low oil pressure there is a little bit of noise but not to bad I would think for a truck with about 230,000 miles. 5.3 ML7 thanks if you have any thought please share.
Low oil pressure issues and this is what i found in my pick up tubes filter

oilcanhenry

The anti-freeze will eat up engine bearings like mad. Likely need to replace or overhaul your motor.

Craig0320

Yup. Your screwed. That is from most likely from all the bearings holding stuff together. How long did you run it with water in the oil?

Timburnswood

Honestly not sure how long I ran the motor with the coolant mixed in the oil I didnt drive with much after I heard a bit of a knock I parked it then maybe had 2 hours of run time my best guess trying to figure out the issue. Today i did the oil pan and mechanical gauge says 9psi lost a psi after cleaning the pick up tube. Then installed the oil sending unit and it was holding at 20 at cold start and at 3,000 rpms around 40psi then got it up to about 120 temp then she dropped back down to 10psi or less. Doesn't say no oil pressure any more just tells me to check oil pressure needless to say I dont hear much of a knock on the low end but the passenger side head has a decent tap thought it's kinda weird only on the one side of the engine sounds noticeable bad.

Craig0320

I have personally seen,drove, and repaired several over 200-260k. Not once did I see any 00-06 nbs with less than 35 psi hot idle. Cold startup is usually around 48-60 range. That motor is on borrowed time. Usually the first main behind the oil pump takes the beating. My first crank journal had to welded just to turn it .010 over when I bought the truck from my uncle after a shop botched a lifter install(ran motor without oil). Had about .030 thousanths of scoring dug into it. I'm just letting you know. Be prepared to drop a used engine in it or spend 2500 and have the machine work done.

Timburnswood

I believe it. After I collected all the metal bits it was the size a dime almost a nickle. Any thoughts if I should even try adding some thicker oil or just get another motor and drop it in? Good thing 5.3l are everywhere and kinda cheap

Craig0320

You can always experiment. Thicker oil may help some but the damage has been done. The bearings have most likely started eating groves in some of the journals. Once they start it just keeps getting worse. Hell through some lucas oil treatment in it with some 10w40 and see what happens.

Timburnswood

At this point is pretty messed up so cant hurt it to much I'll toss in some Lucas and update if it did anything worth wild. If I can get it to a few art shows I'd be happy lost alot of time and money trying to fix something I didnt properly diagnose. Lesson learned...

Craig0320

Everyone makes mistakes. Like you said lesson learned. I was going to comment that a faulty head won't affect oil pressure but the side affects(antifreeze) will. I had to make many mistakes over the years to get where I am.