I drive a 2014 prostar with Cummins engine and I been having low oil pressure around 21 psi when the engine is fully warm but when the engine is cold i get 40 psi. I have put in 2 gallons of oil thinking I had let the oil get to low which caused the low oil pressure. Even when my truck had it’s oil changed and after driving about 6 hours or so the oil psi drops below 40 psi. Then I also started having abs module warning light(tractor only) come on with a upside down triangle which will disappear if I let the tractor rest for a few mins .
I have already taken the truck to the dealership twice already. First dealership said the truck was low on oil but didn’t tell me anything about the abs module warning light. Second dealership only spent a few hours working on it but didn’t really do anything as the oil pressure is still going low below 40 psi and the abs module warning light still comes on once in a while when i am usually stuck in heavy traffic but this morning it came on then disappear when I let the truck sit to go inside the truck stop for coffee or breakfast.
Any ideas what could be causing these problems as I haven’t seen any oil leaks or the truck burning oil and when the engine is warm the oil dipstick shows the oil level near full But showing empty with the engine cold and after adding two gallons of oil.
Should a truck be losing nearly 2 to 4 gallons of oil a week after a oil change?
