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OIL PRESSURE

NJK1500

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NJK1500 Enthusiast

NJK1500

Posted
Posted

I have a 94 K1500 5.7 with 230,000 miles on the motor. Recently lost oil pressure at idle. Ideas? Motor still runs good, uses about a quart of oil between changes, power is good. Should I just replace the oil pump and if so how hard is it to do. Thanks.

snoman Senior Enthusiast

snoman

Posted
Posted

If oil pressure really is zero at a idle, it is probaly a combination of pump and engine bearings. You could try a aftermarket high capacity oil pump to help boost pressure with worn bearings and DO NOT use 5w30. Given engines age you might even try 15w40 oil. 5w30 can have terrible oil pressure in worn engines. YOu could evenntry some STP or Motor Honey (which can boost oil pressure by 5 to 10 psi) and a change to 15w40 before you change pump.

SteveCZ Enthusiast

SteveCZ

Posted
Posted

Could it be that, or could it just be the oil pressure sending unit?

 

I know that went on my dads old 94 blazer.... as soon as you hit the gas, it jumped back up to where it should be, and the motor ran fine...

 

I think the Sending Unit is easier and cheaper to replace than the oil pump...

 

Just my $0.02

snoman Senior Enthusiast

snoman

Posted
Posted
Could it be that, or could it just be the oil pressure sending unit?

 

I know that went on my dads old 94 blazer.... as soon as you hit the gas, it jumped back up to where it should be, and the motor ran fine...

 

I think the Sending Unit is easier and cheaper to replace than the oil pump...

 

Just my $0.02

I would check this but given the mileage, I think it is a wear problem and heavier oil and "honey" will keep it going for a few more years maybe.

awdvkd Enthusiast

awdvkd

Posted
Posted

Did this ocur over a long period or abruptly. It it happened quickly I would think its the sending unit or gauge. If its due to worn parts in the engine it would happen over a longer period of time. Plus if it has oil pressure when its cold and the oil is thick and then thins out as it gets hot it most likely due to wore engine parts. Good luck

NJK1500 Enthusiast

NJK1500

Posted
  • Author
Posted

My son is using the truck and I have not seen it first hand but it seem that the pressure drops when the truck heatsup. This happened Thrusday of last week. Up until then the truck had 35-40 pound of pressure at idle. I think I will try the sending unit and then the thicker oil before looking at the pump. Can the pan be removed easy? Thanks to all for your help

snoman Senior Enthusiast

snoman

Posted
Posted
My son is using the truck and I have not seen it first hand but it seem that the pressure drops when the truck heatsup. This happened Thrusday of last week. Up until then the truck had 35-40 pound of pressure at idle. I think I will try the sending unit and then the thicker oil before looking at the pump. Can the pan be removed easy? Thanks to all for your help

Good plan! I have never pulled a pan on a OBS 4x4 truck in the truck so I cannot comment on that but it seems that the front diff may cause some problems but maybe not.

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