Guy I need help on this Where is the oil pump located on a 5.9 and the Oil pressure releif valve? I am doing some rework on my 5.9 Dealer.

They said they replaced my Oile pump and I would like to know if they did. I know they did not do the Oil and filter My gauge is acting up I know they are dummy gauge but this is the first time this happened. I tink my Oil pressure releif valve is stuck because at idle it is low but as soon as you touch the throttle it back up high. Somebody help me please. Thanks J,C,

 

Oil pump is located behind the timing cover. It is driven by the crankshaft gear. I would use mechanical gauge to verify oil pressure first. Possible bad sending unit giving inacurate pressure reading.

Engine Oil Pressure (MIN)
At Idle 68.9 kPa (10 psi)
At 2500 rpm 206.9 kPa (30 psi)


1 - OIL FILTER
2 - PLUG
3 - GASKET
4 - SPRING
5 - VALVE


Disconnect the battery negative cables.
Remove the threaded plug (2), spring (4) and valve (5). Insert a finger or a seal pick to lift the plunger from the bore.
NOTE: If the plunger is stuck in the bore, it will be necessary to remove the filter head.

INSPECTION




Inspect the plunger and plunger bore for cracks and excessive wear. Polished surfaces are acceptable. Verify that the plunger moves freely in the bore.

Check the spring for height and load limitations. Replace the spring if out of limits shown in the figure.

 

Thank you BigIron7,
Where would you start? They did replace the sending unit to and oil pump. The truck holds in the middle the at full operating temp it falls down to the Low side. The far let black line. Thanks J,C,

 

Depends on how many miles on truck, any engine noises example excessive rod clearance will give audible engine knock. Did they check with mechanical gauge first? Does oil pressure go below min oil pressure spec? You have the proper oil in the engine. Recomend 15w40 for diesel engine. Although it rarely happens a oil galley plug could have come out. This will reduce oil pressure more at idle since the oil pump cannot keep up with the leakage. If the oil pressure at Idle drops to zero most likely oil galley plug has come out or relief valve is stuck open. The only way to verify is with accurate mechanical oil pressure gauge and test the pressure at idle. Donot run the engine if mechanical gauge reads zero or you will do internal engine damage in few minutes of running.

 

Truck has 67K on it and I run Shell 15/40 in it. Motor sounds Great I just don't like the gauge dropping down. I will go over to the auto parts stor tomorrow and get a gauge to check it. What is a good range to look for?

 

If it's not below min when engine is hot. 30 to 45 psi would be best for a engine with under 100k miles. Bearing wear causes the oil pressure to be lower over 100 k miles.