Hi everyone. I just joined the group hoping to find a group of people willing to help me out and answer some questions I have now and in the future as well. I bought an 08 Tahoe LT 4wd back in November and I’m absolutely in love with it. On the other hand it has given me some trouble occasionally but most recently my oil pressure sending unit went out. Due to me not having the tools to repair it myself (I’m no car mechanic but YouTube has a tutorial for anything) I took it to a shop and had it replaced back on the 11th this month. Well today my check engine light popped back up and my oil pressure went to zero so I’m assuming it went out again. Does anyone have any idea why it is having an issue again after having been replaced less than a month ago? I appreciate any advice.
Welcome to the forum from Iowa.
First piece of advice is, didn’t assume a sensor is bad when it shows a fault. If the oil pressure sensor is showing low oil pressure, you could very well have low oil pressure. You didn’t mention anything about confirming good or bad pressure with an analog pressure gauge. Did the shop that replaced it check this or did they just replace the sensor because you asked them to replace it?
A common cause of low oil pressure readings on these vehicles is a dirty screen that is located right below the oil pressure sensor. Did the shop that replaced the oil pressure sensor say anything about checking, cleaning or replacing that screen?
Another common cause of low oil pressure is a bad o-ring on the oil pickup tube on the oil pump. This is where the o-ring fails and the oil pump can’t get a good suction to draw oil from the oil pan.
I would not continue to drive the vehicle until you can confirm that you either have good oil pressure and it is indeed a bum sensor or that you actually have a working sensor and you have low oil pressure and need to find the cause.