P0306 NO MATTER WHAT I DO

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Nickct203

Member
Joined
Feb 2, 2018
Posts
86
Reaction score
49
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.
 

Foggy

Full Access Member
Joined
Jul 25, 2019
Posts
1,093
Reaction score
1,403
Location
KS
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
 

OR VietVet

Multnomah Falls
Supporting Member
Military
Joined
Oct 8, 2014
Posts
20,710
Reaction score
36,491
Location
Willamette Valley
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.
 
OP
OP
N

Nickct203

Member
Joined
Feb 2, 2018
Posts
86
Reaction score
49
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.
 

OR VietVet

Multnomah Falls
Supporting Member
Military
Joined
Oct 8, 2014
Posts
20,710
Reaction score
36,491
Location
Willamette Valley
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?
 
OP
OP
N

Nickct203

Member
Joined
Feb 2, 2018
Posts
86
Reaction score
49
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
 

Forum statistics

Threads
132,301
Posts
1,865,637
Members
96,885
Latest member
BinOdhaib
Top