I feel like we have tried everything. My 2007 silverado has low oil pressure at idle. New oil pump new oil sending unit new o ring bearings look fine no engine noise. Tried thicker oil still when warmed up oil pressure light comes on at idle. when RPMs higher oil pressure goes up. We did check with a gauge and it drops to 0 when warm. I really need help.

 

What's the history? Did this happen all at once or has it been getting progressively worse over time? Worse when hot than cold?

Allan

 

How many miles on the truck? Sounds like you are ready for an engine rebuild. Worn main or cam bearings could cause this problem. In the old days when this occurred, we used STP oil treatment. It would make the oil thicker and increased oil pressure. This would only be a stop gap. It would still need rebuilding.

 

The low oil pressure problem started one evening, no warning. the truck has 136000 kms In the three years since I have owned it I did routine oil changes and really babied the truck. We have only put 36000 kms on truck since purchased. I would have thought if it was bad main or cam bearing I would be getting engine noise. Low oil pressure light comes on only once warm and at idle if the rpms are up the oil pressure is up.

 

I am having the same issue with my 04 Silverado. Just found out today that is the Cam Bearing and now i'm looking to put a new 5.3L in because it seems to be more affordable. Unfortunately i am not set up to do the work my self. Hope things work out for you if it hasn''t worked out already.

 

While the car is idling, the engine is turning a certain RPM depending upon the idle RPM setting. The speed that is turning, is fast enough to keep the oil pressure at a level high enough not to trigger the light. When you place the car in idle (obviously RPM and due to that engine slows down) thus the oil pressure drops to a point low enough to trigger the light. Once you accelerate, the speed of the engine, it warms up and brings up the oil pressure.

 

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Possibly a stuck oil pressure bypass plunger? Just a suggestion. Have you had the vehicle inspected by a certified technician?

Louis
GM Customer Service