Oil pressure drops after warm up on 2007 5.3L Suburban, 128k

[Robco1000]

Hello, exact same problem on 2012 5.3 avalanche with 170k.  Just did the DOD lifters incl. oil pump and drops below 20 at idle, runs at 20 on freeway at 1700 RPM.  Doing filter now, but anyone had any luck on this thread yet?  Going to 10w30 as well. 

[Allen B]

Hi there,

 

I'm having the same problem. 2011 Chevy Silverado, 5.3 150k. 

 

Dod delete (Comp)cam stage 2 .597 

Ls7 Lifters

AMF oil galley plugs

Non-AMF Valley plate 

Upgraded Rocker Arm Bearings

High Volume 18% Oil Pump

Camshaft Gear and GM Cam Bolt

Timing chain and Camshaft Plate

GM Oil Pressure Switch 

Ac Delco Oil Filter

Mail Order Email Tune GREAT TUNER

 

The engine runs smooth with a little chop. But I have a ton and valve train noise on both banks. My rod and main bearings look great. I bore scoped the camshaft bearings; they looked good. My oil pressure at the filter is 45 psi cold and the same at the oil pressure switch, the oil pressure drops to 20 psi at idle warm. The valve train noise get worse has the Engine gets warm and with RPM. No misfires. I talked to my tuner thinking it maybe the VVT solenoid dumping oil pressure due to tune. Nope! 

The only thing I can come up with is the camshaft bearings must have enough clearance that I'm dumping oil pressure at the cam besrimgs and my lifters are starving for oil. 

 

I'm going to pull the valve covers back off and hang the coils up and run the engine to see if I have oil coming through the push rods. If there is no oil making it up to the rocker arms it has to be the camshaft bearings. Does this make sense?? 

 

 

[Boss bigblock]

On 8/21/2021 at 10:14 PM, Johnnyblazed said:

Im having similar issue on 2007 envoy.denali 5.3l. I installed a new mellings high volume pump, with the higher pressure spring as well. Cold it runs beautiful, NEVER any noise regardless of pressure. I checked.pressure with mechanical gauge to.confirm my cluster wasnt bad as i was told the clusters do go bad as well and could generate a false condition so it is important to hook up a mechanical gauge, dont trust the dash gauge, or scanners due to the fact some.may read data from the dash. My performance engine guy and gm tech are suggesting worn cam bearings, while another guy i work with who does.all the engine rebuilding (im a transmission specialist) is suggesting to replace valley plate expeccialy due tonthe fact it is leaking from the rear side. If the gasket is to worn he said it may be leaking to much internally at the seals, at idle 0, stayed 0 while moving prior to oil pump upgrade but now it will increase once rpms are up until it gets even hotter before then it stays at 0 with the rpm increase. If you have afm/dod it may be worth a shot. Another engine guy that does High Performance Engine also suggested a different melling's pump that could possibly patch the problem he said it runs about 75 PSI cold and I would probably still hold 20 to 30 hot but I really do not want to change the oil pump again as it is incredibly difficult while keeping the oil pan on I did it once already and I do not want to do it again the 4 x 4 version is very labor-intensive to drop the pan on my Envoy I am going to try a new Valley plate and see what happens

 

[Labrat0116]

Try 20W-50 oil.

[TazVet]

I've noticed the same problem with my 2007 Silverado LT Ext. Cab 5.3L with 109,000 miles. At high RPM pressure is over 40lb, but at a idle at at stop light it drops to around 20lb or lower. When you get on it pressure goes way up. Doesn't make any noise at anytime. I think I'll try changing the oil pressure switch screen, seems like that's the culprit and it's the cheapest fix.