Oil pressure problem
Thread Starter
Le Mans Master
Joined: Feb 2008
Posts: 5,638
Likes: 1,187
From: Lake Worth Beach, Florida
Oil pressure problem
I've owned my 08 since new and monitor the gages when I drive (160K). The normal oil pressure at 80MPH and 1275RPM is 38Lbs. I recently replaced the radiator and on a recent drive about 1 1/2 hours after the drive I noticed that the engine was still exceptionally hot. I opened the hood and the engine cooled down quickly. The next day I noticed my oil pressure was reading lower at 32Lbs at the same speed. No bad sounds coming from the engine, I am concerned I may have overheated the oil sender switch. Anyone have any ideas what might have occurred. Hoping this one is not expensive.
Pro
Joined: Dec 2010
Posts: 601
Likes: 40
Doubt you overheated the oil pressure switch as the oil usually runs hotter than the coolant. Did you use an "air lift" tool pull a vacuum on the cooling system to help eliminate air pockets in the cooling system while refilling it? Make sure the fans and fan switches are working properly after the install of a new radiator.
Race Director
Joined: Dec 2013
Posts: 12,502
Likes: 3,631
Oil pressure sensor is on the back of the motor, under the windshield cowling.
Mirror and some contortion will allow you to replace it without having to remove the intake manifold.
As for radiator fluid change, chances are, had air in the system still by not putting a vacuum on the tank to dry the last of it out, and why it was reading high until the system purged the last of the air out of the system.
Here is the location of the radiator temp sensor, and with air in the lines, where the air will be trapped in the heads to cause the temp to read high on the sensor.
As for wet sump motor, oil pressure over 30 at idle,and would just call it good enough as is. GM states that lower is fine, but like to use the 30lbs at idle with hot oil the bench ok mark isntead. Lower than this and the sensor good, then it time to find the motor parts wear that is causing the lower pressure instead.
And for the Love of Christ, don't hack a hole in the cowling to change the oil pressure sensor out that way,
Mirror and some contortion will allow you to replace it without having to remove the intake manifold.
As for radiator fluid change, chances are, had air in the system still by not putting a vacuum on the tank to dry the last of it out, and why it was reading high until the system purged the last of the air out of the system.
Here is the location of the radiator temp sensor, and with air in the lines, where the air will be trapped in the heads to cause the temp to read high on the sensor.
As for wet sump motor, oil pressure over 30 at idle,and would just call it good enough as is. GM states that lower is fine, but like to use the 30lbs at idle with hot oil the bench ok mark isntead. Lower than this and the sensor good, then it time to find the motor parts wear that is causing the lower pressure instead.
And for the Love of Christ, don't hack a hole in the cowling to change the oil pressure sensor out that way,
