[BrokeFang]

Ok so this is the first time asking for help on the internet, but I am completely out of ideas and desperate to get my truck running right.

i drive a 06 extended cab silverado with the 5.3 vortex engine. it has 300,933 miles on it. iv owned the truck for almost 2 years and purchased it from an old man who used it to travel from California to Missouri and back.

when i first got the truck it ran like brand new. it recently ran a knock sensor code so i replaced the knock sensors in the valley (the second time after buying cheap sensors on amazon. CHEAP PARTS EQUALS BAD TIMES!!) after replacing the sensors spark plugs and wires (and im not sure if doing all that is related) it begun running rough. its what the shop told me, miss firing on cylinder 7. at about 60 mph or more it jerks (hard jerking at times) town speed around 45mph it seems to run fine. its not a constant jerk and most happens going up hill.

please if anyone can give me ideas of what to do i would really appreciate it. im running out of money and ideas.

I also have a suspicion that it might be the trans or rear axle area. but im unsure at this time

 

[xPosTech]

Any codes after the knock sensor swap? Since you had the intake apart it's important to use the best intake gasket you can. It's also important to torque it to specs. These composite intakes are easy to flex a little if uneven torque. I would check fuel delivery and possible intake vacuum leak.

Ted

 

[BrokeFang]

I haven't had any codes thrown since then. I also checked the intake 4 times for possible leaks. I made so the gasket was good and even silconed the intake gaskets the 4 time removing it to see if that works.

 

[xPosTech]

What about fuel trims? Is the PCM trying to compensate a lean condition in cyl 7 by increasing the fuel trims on that bank?

Ted

 

[j cat]

when you change parts like spark plugs/wires these have to be inspected. did you measure the new wires [ohms ] and compare to new ?

what spark plugs did you install ? IMO ac delco iridium is the correct plug.
then the coils the connections to them can get corroded . the use of silicone dielectric grease is required . I buy tubes of it and place a good amount in the boot ends so I can remove the plug wires easier...

the engine oil to use is synthetic on these engines .. if dino oil then many have suffered failures.

never wash these engines or you will have KS failures ..they have felpro gasket kits much better then GM part ..
at this mileage could be a bad injector or connections to it etc..

 

[BrokeFang]

I'm not sure. I have no advanced tools to do such things

What about fuel trims? Is the PCM trying to compensate a lean condition in cyl 7 by increasing the fuel trims on that bank?

Ted

 

[j cat]

I'm not sure. I have no advanced tools to do such things

many do ask for a one answer solution. with NO testing info so what happens is no help . testing then data posted , then a cheaper faster fix......... new parts and install can cause more problems..