Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
I am sorry your having this problem
is this 5.3 engine a cylinder deactivation engine or also called active fuel management engine where it can shut off cylinders when driving to save fuel ?
where or what area do you hear this knocking noise ?
thank you for that information
where do you hear this noise from ? is it a ticking type noise like a lifter noise ?
any idea what the code numbers are set ?
any local Pep Boys or Auto Zone will scan the codes for free for you
we need to know if this is just 1 or 2 cylinders misfiring or most of the cylinders so we know which direction to take next with this problem
this issue can range from a fuel pressure issue to most common a possible cam shaft or lifter failure which will cause the light to be on and blink and the noise
when the check engine light is blinking there are cylinders misfiring
the 2 things you have going bad for you right now is this noise and a misfire which on these usually ends up being a lifter or cam failure
if you get the codes read and there is a specific 300 code like a 301-308 those are all 8 cylinders
if say you have a code 304 which is cylinder 4 we would need to be sure the park plug is ok if it is remove the valve cover and see if the rockers are opening up correctly if not the lifter and cam shaft is usually the issue
if the rockers are good then swap 4 cylinder injector with 6 and see if the skip moves or stays at 4 cylinder
the MAF can cause most of those codes to be set if it is not sending the correct air flow reading to the computer
the knock sensor is touch and go if the MAF is causing that code as we have had knock sensors going bad and the wiring harness to them from under the intake manifold
if the fuel pressure tests good and hold pressure i would replace the MAF and the connector at the MAF and shrink wrap in the new wires one at a time so you do not mix them up then clear all the codes and see how it runs and which if any codes come back
yes it could be
you need to be sure the grounds are all clean and tight on the engine and the ground # ***** in this picture must be clean and tight and the grounds on the drivers side lower of the engine where the negative battery cable connects to the engine there should be the negative cable and another small ground together