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I hope someone on here can help with a big problem in my 2011 GMC 1500. The truck has a 5.3 in it and about a month ago one lifter started tapping. I called a few people and they suggested running some Marvel mystery oil in it for a while and I did and it helped for a while. I pull trailers everyday and last week it started making some noise which I thought was the belt. When I got home the truck had a PO302 code and after some checking I decided it was a lifter noise. To make a long story short I decided to do a afm/dod delete but when I took the cam out the 2 front lobes on #2 were in pretty bad sharp on was one of the lifters. The 3 front cam journals are scored as is the front cam bearing I can’t make out the rest of the bearings. The truck has around 125000 and the oil pressure sitting is around 15 lbs and driving it’s 25 to 30 lbs. What should the oil pressure be on one of these engines? I’ve never worked on one of these motors and I don’t know how thing should look after what happen but I’ve been told to put a cam and lifters in it and run it but I’m old school and I’m wondering if I need to do a complete overhaul.
You already know... It needs at least 10 PSI of oil pressure for each 1,000 RPM. Most LS's I'm familiar with will easily idle at 40 lbs. of pressure at a hot idle and go up from there when the engine is revved. Based on those pics you need a NEW cam, NEW cam bearings, and at least a few new lifters. Since you are deleting AFM/DOD you will need at minimum 8 new lifters (to replace the DOD/AFM lifters) and potentially a few more if any of the other NON-DOD/AFM lifters are damaged. Sorry this has happened to you... and at such low mileage. Has this engine had the oil changed every time the DIC indicated it was time? I can't imagine why it has had such a short life.. Odometer been turned back? Something is not adding up... 125K miles an LS should have few, if any, issues at that low mileage.
Install a new lifter with some motor honey and trade it in. I had a 2006 4x4 1500 with 342k it was getting a rod knock when I went to trade it in. The dealer said it was running so quite and smooth I just smiled and agreed. With that honey in it the pressure was 40 at idle.
What kind of oil have you been using?
Low oil press can be from a number of things, but it can be from that little screen that sits under the oil pressure sender getting clogged up (very common). I've seen much worse cam bearings than what are pictured above.
If it ran good other wise I'd throw a new non-dod cam and lifters in there and enjoy. Had to do that with my 07 Yukon 5.3 when one of the lifters took a **** on me.
Be advised though if you choose to elim the dod, you have to have the computer programmed to run w/o it. There's a guy that does it for like 50.00 including shipping of the computer.
I don’t know much about the truck ,it had 110000 miles on it when I purchased it. My guess is the guy just drove it and probably never change the oil. When I got it the oil was clean like it had be changed, it ran and drove great. I’ve had the truck for 2 years and I’ve been changing the oil every 5000 miles with 5w30 synthetic oil. The engine was Nastier than I expected so I’ve decided to pull it out and rebuild it because I plan on keeping it for awhile. I had the dod programmed out the week after I purchased it. I was hoping the motor would have been cleaner than this or is this normal.
Install a new lifter with some motor honey and trade it in. I had a 2006 4x4 1500 with 342k it was getting a rod knock when I went to trade it in. The dealer said it was running so quite and smooth I just smiled and agreed. With that honey in it the pressure was 40 at idle.
What kind of oil have you been using?
From: Halfway back on the Highway to Hell...again!
Professional advice.
Most likely a lot of metal got through the entire engine and low oil pressure is key sign. If you really want to keep it, you have 2 choices,
1. re bearing and re ring it, new oil pump and cam/lifters and associated parts.
2. Buy a reman engine and keep driving.
But do your research. Many bolts in an LS are TTY.
We'll, you seem very mechanically inclined so keep going and fix it. Would of been nice to do some more checks before tearing into it (like remove the screen i mentioned to see if pressure cam up, etc).
At this point, it may be easier just to take the engine out since your just about there. Everything seems pretty clean inside based on the photos. Check all the bearings, change the pump and run it!!!
Yes
They paid 5k for it 3 years ago. More then a fair price. 2006 4x4 z71 they had it on a lot for 8k. if your buying a 342k truck you can expect it’ll need a motor soon.
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5.3 lifter problem 
