Cm871 oil pressure loss

[Murray Farms]

After watching "1 million mile rod and main bearings"I decided to pull the oil pan. Virtually no sediment, using a magnet, picked up metal filings totaling less than 1/8 of a teaspoon. Performing pressure coolant test now. Pickup tube o-ring is a very loose fit, is this common? Has putting dimes under the oil pump spring been beneficial? Anything else I need to examine?

[Signature620]

The oil pump can get a lip where the pickup oring sits and allow the pump to suck air. It could contribute to your low oil pressure but it's unlikely.

[Murray Farms]

Thanks Signature 620! there is a deep groove in one side of the aluminum as if the pickup tube was not centered properly. New pump is cast iron and does not require shimming. Backlash must be between .003 to .022 in. I'll post the outcome in soon.

[Signature620]

If there was a large P clamp securing the pickup tube to the block stiffener plate, discard it. Hopefully aerated oil is the root of your problem!

Let us know.

[slowpoke]

just curious why the P clamp should be removed, is that for all cm871's

[Signature620]

The P clamp tends to help create those grooves in the oil pump by holding the pickup off centre in the pump housing.

The pickup is best left to find it's own centre without the clamp.

[Murray Farms]

Oil pressure is now 26 PSI at idle 39 going down the road with oil temperature at 190°. noticed when I tightened the P clamp it pulled the tube sideways in the pump inlet. I Elongated the holes and was cautious to keep tube in the center when tightening the clamp.Unfortunately I already had the pan on when I read your suggestion to delete the clamp. Thanks again!

[david24]

(09-28-2019 )Rawze Wrote:  replace the oil filter and see if you have same problem.

BTW: Fleetguard filters do not have any pressure loss problems --- SOOT-PACKED ENGINES CAUSE PLUGGED OIL FILTERS! -- And if the factory brand of oil filter cannot keep up with it -- YOU HAVE SEVERE ENGINE PROBLEM, NOT A FILTER PROBLEM!!!

If A FILTER SOLVES IT, then the engine is severely soot-packed and needs not only an oil change again to remove some of the soot, but someone needs to find out why the engine is getting soot packed and making way too much soot!. - that problem can kill the engine in no time.


lastly --- WHO IS THE MORON WHO WOULD DRIVE THE DAMN THING KNOWING THE PRESSURE IS BELOW 30 PSI (should be 34-36 psi though) GOING DOWN THE ROADS --- I SUPPOSE SOMEONE JUST DON'T CARE THAT IT COULD SPIN A BEARING OR WORSE???--- SOMEONE NEEDS TO NOT DRIVE THAT THING LIKE THAT!!!!!!!!!!!!!!! -- IF I HAD A DRIVER THAT DID THAT TO MY TRUCK I WOULD HAVE FIRED HIM ON THE SPOT!@

if the oil filter does not fix the oil pressure loss issue then someone needs to find out where that thing is hemorrhaging oil internally. Start by looking under the valve cover with the enigne running... http://rawze.com/forums/showthread.php?t...1#pid41261

next... would be this list of stuff...
http://rawze.com/forums/showthread.php?t...9#pid31999

If oil pressure is above 36 going down the road is that a problem? Say around 40 psi

[Lonestar10]

New Cummins oil pumps are rated at higher pressure