2007 Low oil pressure
 

I have a 2007 Silverado Max with 6.0L. The other night while driving home the check engine light came on and I noticed the oil pressure was at 20 psi, which is unususally low for the truck. The next day I drove down the road for about 2 miles and the oil pressure went to 0 and the warning message to shut engine off came on. Pulled over and checked oil and it was full. Cranked truck and message went off and had 15 psi of oil pressure. Drove truck home and oil pressure went to 0 again as I pulled in driveway. Truck has 62000 miles and oil has been changed regularly. Called the dealer and he said it would only be covered under warranty if its internal engine problem. So I went ahead and put a new oil sending unit on and its still doing the same thing. Crank truck and it has 15 - 20 psi oil pressure until you run it for a little while and it goes to 0. Dealer says to figure out what it is and bring it to them if its internal. The engine is not clicking or making any kind of bad racket. I also changed the oil just to make sure the filter did not have a clog or something. Anyone have any ideas? Should I just tow it to the dealer and absorb the cost if its not under warranty?

could be the pump. if the dealer pulls the pan just to check the pump, does warranty cover that? if so, have them do that.

I went ahead and put a new oil sending unit on and its still doing the same thing.

IMO theres an internal problem then.

oil pressure
 

did you ever find the problem?

My 2001 (143k) Tahoe with the 5.3 is doing the same... I also replaced the pressure sending unit and it still is at less than 3 at idle (oil pressure light on) with the max at 22 psi at 1500 - 2000 rpm at speed. Did you ever find out what the problem was??

My low oil problem happened while on a trip I pulled it in to a oil change shop and had the oil changed and that fix my problem. I dont understand how some GM engineer figured a small oil filter is what they needed on these big V-8's.

If you've already changed the filter and sending unit and still have this problem then a true low oil scenario like mine you experience serious valve lifter tapping and hard running at idle. If this isn't the case then you could have wiring issues. A mechanical gauge can verify you have pressure but its not a fix since it wont run electrical to the ECM to keep the light off. Would just be something to let you know where you stand at less the cost of 1hr of dealer labor.

Low or no oil pressure in Silverado
 

I have the same 07' Silverado with the 6.0 & 65K miles and am having the same issues. I did change the oil sending unit back in Feb. and that solved the problem until now. I tried to change it again but the problem has not changed. I decided to use the process of elimination and add a manual oil pressure guage to verify if I have pressure or not. If I do have pressure with that guage then I know that the problem is not with the pump, but with the factory guage itself. I was told at the dealership that the cluster will have to be pulled and sent for repair. Cost? Not sure. So my advise is to buy a cheap SunPro guage and T that you can use the factory sending unit and aftermarket guage unit to verify pressure.

See my reply below. MAX 6.0

thicker oil?
 

what about running thicker oil?