Loud knocking noise that intensifies when accelerating

SSEELEY1

MEMBER
2013 GMC YUKON
5.3L
V8
2WD
AUTOMATIC
107,000 MILES

My vehicle is making a loud knocking noise and it intensifies when I step on the gas. The code that came up when my check engine light came on is P0307 which is a misfire on the seventh cylinder. I replaced the coil and the spark plug and that didn't stop the knocking sound. My guess is that the lifter has completely collapsed and needs to be replaced.

I have access to a facility with all the tools necessary to fix this problem myself. Can you please give me a list of all the parts I'll need to complete this repair?

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,758 POSTS

Welcome to 2CarPros.

I will be happy to help, but we need to know what is happening first. First, I really feel you need to check compression in that cylinder to see if there is an issue with a bearing or if it is related to the lifter. Or, you could remove the valve cover to see if the valves are moving when you crank the engine.

First, take a look through this link. It discusses different sounds that are made by an engine. See if there is something that mirrors what you hear. My biggest concern is that it is a connecting rod bearing or even a cam lobe that is bad. You would need to remove the valve cover to see if the valves are moving. If they aren't, then the intake has to come off to see if it is a lifter or the cam. You know, there is even a chance the rocker may have failed.

I have the directions for any of the things that it could be, but I would hate to give you directions for a lifter only to find out the noise is still there once you do all the work. As I mentioned, a knock is usually related to a connecting rod bearing or even a main bearing in the engine.

Take a look through this link and let me know your thoughts so I can provide the correct directions.

https://www.2carpros.com/articles/engine-noises

Let me know,
Joe