Bad Oil Pump

[mpd13078]

So my ole blue is parked till spring as a project now. Made these videos & showed them to an ASE Master Mechanic I know, with him confirming 99.9% without working on it, it's the oil pump. Oil level is good, oil dipstick has no fuel smell, no head gasket floaties in the coolant. Been paid off a long time so I'll fix it when weather permits. Time to buy another vehicle.

 

[littleblazer]

I'm not sure how the oil pump operates on these but if it's like an ls... it could just be the bypass is stuck. Videos some times exaggerate noises, is it actually knocking or clunking that bad? It does sound like it but I just want to double check.

 

[mrrsm]

I actually favor @littleblazer 's theory here... but to cover two other possibilities, I'll mention here that before 2004... there were some sketchy events with Failed Oil Pump Pick Up "O"Ring Gaskets that seal the Oil Pump Pick-Up Tube to the lower pocket base of the Gerotor Style Oil Pump. These images will show how the smaller Center Gear wrapped so snugly about the nose of the Crankshaft is damned near in a "Solid State" condition and when married to the eccentric Outer Gear... is an almost Bullet-Proof method for reliable Oil Delivery that is almost impossible to "break" in the classical sense. Ergo... if the Oil Pump By-Pass Valve Spring Tensioned Cylinder gets stuck inside the Oil Pump Housing...the Oil would immediately dump right back inside the Crankcase.

But... if the "O" Ring Gasket itself either ruptured or the Fastener holding it in came loose... no oil would be available to get pulled up from the Crankcase... because it would be impossible to pull a vacuum with the seal broken. You can easily demonstrate this principle by nicking a small hole in a Soda Straw and then try to sip on a McDonald's Diet Coke... and see what happens.

The images I have attached are of the Updated 2004 Gerotor Pump with some additional explanatory documentation on WHY they made these changes to their design and stress the fact that the New Gerotor Oil Pump will NOT work with the Old Style Oil Pick-Up Tube. The most critical problem though is wondering how long the engine was running before it was finally shut off... and because unlike most people facing this difficulty... you instead have enough Faith in your 2003 "Baby Blue Trailblazer" not to give up on it... and so THIS is a very solvable problem... but it is quite an involved Repair:

 

[Mooseman]

I haven't heard of any of these pumps failing outright. If you're getting a low oil pressure condition and the noise is not as it sounds in the video, it could be the oil pressure switch. Next, as @MRRSM indicated, a bad O-ring is possible. Since the oil pan has to be dropped at this point, might as well change the oil pump just in case.

 

[mpd13078]

It's as bad as it sounds. Knocking like a diesel. Glad the videos uploaded, my first time doing that.