No Oil Pressure 03 Suburban

krandall · January 21, 2008

My wife went to start her suburban this morning to warm it up. By the way it is 3 degrees this morning but it was 20 below yesterday and there was no trouble. Anyway she we went back out 15 min. later and her warning buzzer was dinging , cluster was saying low oil pressure , and the gauge was reading practically 0 . I think if it ran that long something should of happened. There is no noise in the engine.No knocking or lifter ticking.It has 68K miles on and never had any problems. Yesterday I did syncro another key fob and I did not start it after that, but I would think that would of caused this. I just started it again and the oil pressure gauge just slightly moves .

MountaineerTom · January 21, 2008

That year and engine is it?

If it's the 5.3, I would check the oil level to make sure it's correct. If it is, you might consider changing out the oil pressure sending unit. If i remember correctly, it's located on the driver's side back of the engine, near the firewall. It should be a relatively easy swap. Should just be a connector to disconnect, screw it out, screw a new one in, reconnect connector. Having clearance to get to it may be the biggest problem. I had to change one on my '91 with a 350 and I had to take the distributor out to do it. If it's a 5.3, it won't have a distributor, so it may be a lot easier.

If it's the oil pump going bad, thats a different story. The oil pan has to be pulled off to change it out. It still can be done by a do-it-yourselfer, but a little more involved.

Good luck.

I found a picture I scanned from my Haynes manual years ago of where the oil pressure sending unit is on the 5.3.

krandall · January 21, 2008

Oil level is full. I was wondering if a scan tool would tell the correct pressure even if the sender was bad.

MountaineerTom · January 21, 2008

i'm not sure if they do or not. Some auto parts stores will let you use a scan tool free of charge to find out what the problem is. Auto Zone does it in the area I live it. If you have one of those you could see if they do it in your area too, or call around some other parts stores to see if they offer that.

krandall · January 21, 2008

I went to move the suburban into the shop to take a look at it and I noticed someting else. I have lost all gauge functions . No speedo, tach amp temp or oil pressure. The good news is I am not worried about the engine anymore. Does this sound like a faulty cluster?

MountaineerTom · January 21, 2008

It could be I guess. I had to have the cluster changed out of my '99 after about a year, but the only thing not working on mine was the lights in the odometer/gear selector screen. If you have to get a new cluster, look into getting one from a 2/4 ton, Denali or Escalade. They have a trans temp guage and if her Suburban is like my truck, the wiring is all ther, so the guage will work when plugged in. You will have to have the milage programmed into the new cluster no matter which kind goes in.

krandall · January 21, 2008

I started it up again and now everything is ok. I guess this is just one of those possessed vehicles. But I am pretty sure this is not over yet .

Draenor · January 21, 2008

Check the connections going to the cluster. Either The cluster is defective, something is loose, or there is a grounding problem.

krandall · January 28, 2008

Our luck could not get any worse. She was driving today and the oil gauge was going thru its little phase again. She called me and I said you might as well keep going. I talked to the service manager of a GM dealership last week and he thought it sounded like a bad connection in the fuse block or a bad cluster but it should be okay to drive it until it gets looked at.She called me back 1 min later and said it acted like it missed for a second and then it died. I went to look at it figuring there was going to be a short or bad connection but as soon as I turned the key I knew it was bad. The motor would not turn over and I am unable to manually turn it over. The belt moves so far and thats it. I would assume the oil pump failed and locked the motor up. If it was not for that stupid cluster acting up last week I would of told her to shut it off and do not drive it anymore. I never would of guessed that you could have an electrical or cluster problem and a bad oil pump in the same week but I guess it has to happen to somebody.

HawkScot · January 28, 2008

I wouldn't give up so fast. You may still have an electrical issue. I have run into motors that I could not budge with the belt and they were fine. You didn't describe what happened when you turned the key, nothing or clicking may be no voltage. Of course if you heard the starter engage, but not turn the motor, then that could certainly be mechanical... Let us know what you find out.