2008 tahoe 5.3l. Wife was driving and went to take off from a red light and truck stalled. She got it running and the cel was flashing then on constant, and the service stabilitrak and traction control came on. She limped it home and I got a P0306 code. Did plugs and wires and still P0306. Swapped the coil pack to a different cylinder and still P0306. Changed the fuel injector still p0306. Took off the valve cover off cause it was a mix between a knock and a tick that you clearly can hear what cylinder it was coming from. Saw cylinder 6 valves were not able to move and the rocker arm wasn't touching it. Read that's a common issue with the AFM. Pulled the head and got another 1 from O'Reillys. Got everything back together and guess what still p0306 and still running like crap. Very rough idle, no power, not as bad a sound but can still hear a small tick. Ran a compression test and psi ranges from 125psi to 150 psi. Cyl 6 coil pack has power and ground, cyl 6 has a brand new fuel injector. Also when I pull cyl 6 spark plug it smells like fuel and is a bit wet. I am at a complete loss for what to do next. Can someone please help me.
P0306 NO MATTER WHAT I DO
- Thread starter Nickct203
- Start date
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Your AFM lifter(s) have failed.. That's what needed replacing when you pulley the cylinder head.
Also, if keeping AFM activated, you'll want to replace the VLOM as well or you could be
in the same boat shortly with the new lifters
Also, if keeping AFM activated, you'll want to replace the VLOM as well or you could be
in the same boat shortly with the new lifters
Are you sure you got that compression reading from cylinder #6? I was gonna answer earlier about lifters problems but when I saw the compression reading, I felt like I needed to wait see what the rest of the story is.
I replaced the plugs, wires, took a coil off my silverado and nothing changed. Pulled the valve cover as my buddy suggested and saw that cyl 6 valves were both stuck in the same spot. I bought a head from oreillyauto.com cause that was the only place that i could find that had it in stock. No i didnt replace the lifters. I tested it 4 times just to make sure they didnt sell me a bad head. What i did just notice is with the truck running i unlugged cyl 6 coil pack and it didnt change the way the engine was running. So im assuming cyl 6 is not firing at all.
Ok that definitely my screw up. I'll pay for that 1. Will bad lifters cause the coil not to fire also? And what are the chances that the cam is bad also?
I would do a big tear down and do the other head for balance and get a look at that cam. Any metal in the oil?
No metal at all. Not even a glimmer of metal or glitter. I don't have the time or money to do a full tear down. This sux
Ok, I can swing buying the stuff for the troubled side, just not both. I appreciate the help
I would wait until you can afford it. The cam could be pitted and if that’s the case it will ruin the new lifter and you’ll be doing it all over again. I would tear down both sides that way you can get a good look at the camshaft through the lifter holes while you spin it over.
That is why I recommended what I did about the teardown. Band aids tend to come back and bite you in the ass. Tear it down once and look at it and then KNOW what the cost is to fix it right.
Everything you guys have said has help tremendously. I was looking at the kits, they are not as expensive as I had thought, but there are afm delete kits and regular afm kits. Which is honestly better?
I don't have to deal with AFM on my 2005 but there are bunches and bunches of threads here to read thru about the plus and minus of AFM.
+1. I assembled my own kit so I could get exactly the parts I wanted for my 2012. The kits are composed of compromises to get to a competitive price point. E.g. in my case, they all had cams designed for the 5.3 but were "compatible" with the 6.2. I wanted a cam that was engineered specifically for the 6.2. Since you have the 5.3 though, most of the kits would likely be a good match for yours.
I appreciate all the info you guys have given me. It's definitely made things easier for me. Believe it or not the kits for the afm delete are cheaper. I'm going to pull the valve cover and head on the driverside and see what it looks like. Hopefully the valves and springs are still in good shape. Thanks again for everyone's input. Once I'm finished I'll check back to let everyone know how it went
Good luck and please do let us know what you find.
