oil pressure reading and low alarm is going off on Chevrolet Tahoe?

This is either a faulty oil pump or a restriction of the oil pick up tube.most likely the oil pump pressure relief valve. If there was no knocking or engine noise most likely the bearings are good.Do not run engine for extended time without oil pressure.here is how I would diagnose & repair.

Oil Pressure Diagnosis and Testing

Tools Required

•	Pressure Gauge

•	Oil Pressure Tester

1. With the vehicle on a level surface, run the vehicle for a few minutes. Allow adequate drain down time, 2-3 minutes, and measure the oil level.
2. If required, add the recommended grade engine oil and fill the crankcase until the oil level measures full on the oil level indicator.
3. Run the engine briefly, 10-15 seconds, and verify low or no oil pressure on the vehicle gauge or light.
4. Listen for a noisy valve train or a knocking noise.
5. Inspect for the following conditions:

   •	Oil diluted by water or glycol antifreeze

   •

   Foamy oil

6. Remove the oil filter and install

1. Install the special tool.
2. Run the engine and measure the engine oil pressure.
3. Check oil pressure specifications
4. If the engine oil pressure is below specifications, inspect the engine for 1 or more of the following conditions:

   •	Oil pump worn or dirty

   .

   •	Oil pump-to-engine block bolts loose

   •	Oil pump screen loose, plugged, or damaged

   •	Oil pump screen O-ring seal missing or damaged

   •	Malfunctioning oil pump pressure relief valve.

   •	Excessive bearing clearance

   •	Cracked, porous, or restricted oil galleries

   •	Oil gallery plugs missing or incorrectly installed

   .

   •	Broken valve lifters

   Repair as necessary.

5. If the oil pressure reading is within specifications, inspect for the following conditions:

   •	Plugged or incorrect oil filter and/or malfunctioning oil bypass valve

   •	Malfunctioning oil pressure gauge or sensor

   Repair, as necessary.

The repairs can be done with the engine in the vehicle.

do i have to remove everything off the front of the engine to access the pump which i beleive is under timing chain cover?

So yes, you have to remove.

taking off bottom pulley

The crankshaft pulley bolt is removed by turning counter clockwise.

Remove the crankshaft balancer bolt.

Do not discard the crankshaft balancer bolt. The balancer bolt will be used during the balancer installation procedure.

Now remove and replace the pump.Put everything back and oil pressure should be fine.

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Car no start:--

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