Low Oil pressure still!!!!

[MalcDogg]

I have 08 Tahoe 5.3L

Changed the Oil pressure sensor, Pick up tube, High volume oil pump installed and pressure relieve valve and still getting low pressure anyone got any info?

I did notice the pan was dirty I’m reading about the oil filter to use the AC Delco filter

 

[Fless]

Moved you here from the General Discussion area.

 

[Dustin Jackson]

@MalcDogg If you have already started a thread about this I would recommend continuing on that thread instead of starting a new one or else I will have to ask a bunch of questions again LOL Can you link it here at least?

 

[lspann3525]

Has the oil pressure sensor filter been replaced or removed?

 

[Tonyv__]

I have 08 Tahoe 5.3L

Changed the Oil pressure sensor, Pick up tube, High volume oil pump installed and pressure relieve valve and still getting low pressure anyone got any info?

I did notice the pan was dirty I’m reading about the oil filter to use the AC Delco fil

I think some of these engines have a small screen under the pressure sensor that gets clogged, did you check for that? Also try to confirm with a manual gauge

 

[OR VietVet]

Sure would help to know what the oil pressure was before all this work and what the pressure is now. Plus, what was the oil pressure when you were satisfied with it before you noticed a "problem" and decided that you needed to do all this work? Did you change the screen for the oil pressure sensor?

@lspann3525 and @Tonyv__ both beat me to it while I was typing. The screen question, that is.

 

[Trey Hardy]

I’ve changed my screen 3-4 times already in the past 100,000 miles I’d check that first as it’s the cheapest to fix it’s just a pain to get too but it’s manageable. I’ve got it down pat now where I can get it done within a hour start to finish
Lil screen under the oil pressure sensors you need a angled pick to get it out

 

[strutaeng]

If it's not what has been already mentioned, it's most likely bearings, either rod, main or cam.

Was the oil pressure loss slow or all of the sudden it happened? You didn't see any glitter on the pan when you removed it or on the oil?

 

[Tonyv__]

If it's not what has been already mentioned, it's most likely bearings, either rod, main or cam.

Was the oil pressure loss slow or all of the sudden it happened? You didn't see any glitter on the pan when you removed it or on the oil?

This was gonna be my next comment. If the screen doesn’t fix issue, might have to chalk it up to worn internals.

I’m in the same boat with my (ly6) 6.0, has low miles but a TON of idling hours. Oil pressure hovers around 10psi. Replaced all of the above, has to be worn internally. However, I’ve had it close to 4 years and put 40k miles on it with this oil pressure.

 

[strutaeng]

This was gonna be my next comment. If the screen doesn’t fix issue, might have to chalk it up to worn internals.

I’m in the same boat with my (ly6) 6.0, has low miles but a TON of idling hours. Oil pressure hovers around 10psi. Replaced all of the above, has to be worn internally. However, I’ve had it close to 4 years and put 40k miles on it with this oil pressure.

Interesting on the idle hours. But I guess a lot of idle wears engines, any engine.

My 4.3 Vortec in my 99 Silverado NBS slowly started to drop oil pressure. I think I noticed after I did the intake manifold, which was in the winter. By summer my check gauges were coming on. I drained the oil at some point and saw like a faint layer of glitter, so I knew it was on its last legs.

At the time I didn't have money because I was in the middle of a large home renovation project, so I just dumped 50 weight oil and kept on trucking. Oil pressure increased another 2-3 psi to about 8 psi. I ran it another 8-10 k miles. It still ran fine, no knocking.

After I retired the engine I tore it down and all bearings had severe wear: main, rods and cam. Clearances were 5-6 thousands compared to about 1.5-2.0 thousands specification. Probably could have overhauled it, but a junkyard 5.3 was much cheaper and a good upgrade from the V6.

Not saying that's your case (hopefully not), but may want to think about your options if it is.

 

[Tonyv__]

Interesting on the idle hours. But I guess a lot of idle wears engines, any engine.

My 4.3 Vortec in my 99 Silverado NBS slowly started to drop oil pressure. I think I noticed after I did the intake manifold, which was in the winter. By summer my check gauges were coming on. I drained the oil at some point and saw like a faint layer of glitter, so I knew it was on its last legs.

At the time I didn't have money because I was in the middle of a large home renovation project, so I just dumped 50 weight oil and kept on trucking. Oil pressure increased another 2-3 psi to about 8 psi. I ran it another 8-10 k miles. It still ran fine, no knocking.

After I retired the engine I tore it down and all bearings had severe wear: main, rods and cam. Clearances were 5-6 thousands compared to about 1.5-2.0 thousands specification. Probably could have overhauled it, but a junkyard 5.3 was much cheaper and a good upgrade from the V6.

Not saying that's your case (hopefully not), but may want to think about your options if it is.

I commented about it before in other threads. I have 88k miles and roughly 9000hr on the 6.0 and that’s equivalent to like 3-400k driving miles. The oil doesn’t look to bad though, I should consider sending it into blackstone for a professional opinion.


In my mind Ive accepted that the engine is running on borrowed time. I’ll replace it when the time comes, just have to decide if I’m gonna go with a junkyard engine or reman

 

[MalcDogg]

Has the oil pressure sensor filter been replaced or removed?

Yes has a new screen and sensor

 

[MalcDogg]

Moved you here from the General Discussion area.

Ok thx

 

[MalcDogg]

@MalcDogg If you have already started a thread about this I would recommend continuing on that thread instead of starting a new one or else I will have to ask a bunch of questions again LOL Can you link it here at least?

This is a new thread

 

[Dustin Jackson]

@MalcDogg How low is your oil pressure?

 

[MalcDogg]

@MalcDogg How low is your oil pressure?

 

[MalcDogg]

Starts high but after driving for 30min it goes low never to zero

 

[MalcDogg]

I took off the valve covers and I don’t have the updated valve covers
Order them today

The oil pressure starts between 20-40 then after driving for 30min it goes below 20 never gets to zero I do get a lot smoke from tail pipe on start up that’s it goes away after 5min engine is running fine but the low gets low after a few days have to add a quart or so

 

[Roger906]

This was gonna be my next comment. If the screen doesn’t fix issue, might have to chalk it up to worn internals.

I’m in the same boat with my (ly6) 6.0, has low miles but a TON of idling hours. Oil pressure hovers around 10psi. Replaced all of the above, has to be worn internally. However, I’ve had it close to 4 years and put 40k miles on it with this oil pressure.

If it doesn't have lifters ticking ( they get oil first) there isn't much advantage to rebuilding it right away.....run it!

 

[BG1988]

I have 08 Tahoe 5.3L

Changed the Oil pressure sensor, Pick up tube, High volume oil pump installed and pressure relieve valve and still getting low pressure anyone got any info?

I did notice the pan was dirty I’m reading about the oil filter to use the AC Delco filter

you didn't install the gen4 (as seen in the "corvette" gen 5 engines) tahoe hybrid Variable oil pump that baby is putting out 45psi at idle hot and 60psi at 1800 rpm


Put some MotorKote in it... that stuff will run with water in the engine..(use oil though )