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We have a 2000 mack ch600. With a mack engine. We lose oil…

We have a 2000 mack...
We have a 2000 mack ch600. With a mack engine. We lose oil pressure when the unit warms up. We have already pulled the main and rod bearingas and inspected no damage or wear. What could be the source of the drop in oil pressure?
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Answered in 4 hours by:
1/15/2013
Technician: Cat Man, Cat Engine Expert replied 9 years ago
Cat Man
Cat Man, Cat Engine Expert
Category: Medium and Heavy Trucks
Satisfied Customers: 10,344
Experience: I am ASE Master Truck Certified.
Verified

Hi Terry. Thanks for using JA! I will try and help you out.

 

If the rod and main bearings are OK, I would suspect you have a oil filter relief valve in the oil filter housing that is opening, or the relief valve in your oil pump is opening. I have seen this before. When the oil is cold and thick, the open valve will not cause the pressure to drop until the oil gets hot and thins out.

 

Since you have removed the oil pan and inspected the bearings, you may also want to take a look at the cooling jets for the cylinders and make sure they are all intact.

 

Please reply back if you need more help or have more questions. I am happy to assist.

Cat Man
Cat Man, Cat Engine Expert
Category: Medium and Heavy Trucks
Satisfied Customers: 10,344
Experience: I am ASE Master Truck Certified.
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