Oil pressure slow to build at startup

[Matthew Jeschke]

For what it's worth

@62f ambient

Thanks! That is super helpful. That pump is pretty awesome. Mine is around a second or 2 slower but you're right is probably fine

I became really attentive to startup pressure as I pulled valve covers off and cleaned up lifters. I was worried running all that cleaner through motor might change my clearances on main bearings. (Probably just rumor that it could do that on high mileage motor).

I just want motor to last till I can find a 6.0 to swap in


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[SnowDrifter]

Not unless ya washed the oil out of the main bearings, which would be difficult. In which case put the pedal to the floor and crank it for 15 seconds. Barring that, an couple short oil changes to get the solvent out and Bob's your auntie

 

[rockola1971]

Oil pressure looks good but that delay in the pressure coming is weird. Ive never had a GM (And thats just about all ive ever owned) do that. My (2) 2003 Tahoes and my 2005 Yukon Denali do not do what yours is doing. Mine come up immediately without any delay. That looks like it could possibly be in the oil pressure gauge. If it were me I would get a mechanical gauge on it to check to see if the oil pressure is actually doing that. Could be the oring on the pickup tube getting ready to dump on you.

 

[Matthew Jeschke]

Good points. I think I'll start with the sensor.

 

[rockola1971]

Good points. I think I'll start with the sensor.

Oil pressure sending unit, wire connection at sending unit check for corrosion, oil pressure gauge itself, connection to instrument cluster for oil pressure gauge check for oxidation or corrosion then the nasty stuff like pickup tube oring, bypass device in oil filter adaptor, internal engine fault (bearings) or ????.

 

[dougo]

Typical varnish build up in the oil passages I would add Marvel Mystery oil at your next oil change some people use sea foam use per the directions ,

 

[cam3439]

Based on your oil pressure and oil weight that you’re running, I don’t think your bearings are shot.

If you’re going to tear the front apart to change the o-ring on the pickup tube, I’d recommend changing the oil pump, since you’re already in there. The pump does eventually wear out and can allow oil to bleed through; not to mention the pressure relieve valve possibly being slightly stuck open (debris or a scratch along the cylinder can cause this).

My 2005 Tahoe historically sat at 30-32psi when I bought it, but I changed out the pickup tube, o-ring and pump. Now my oil pressure picks up and idles like normal.